Welcome to Cilium’s documentation!¶
The documentation is divided into the following sections:
- Getting Started Guides: Provides a simple tutorial for running a small Cilium setup on your laptop. Intended as an easy way to get your hands dirty applying Cilium security policies between containers.
- Concepts: Describes the components of Cilium, and the different models for deploying Cilium. Provides the high-level understanding required to run a full Cilium deployment and understand its behavior.
- Architecture: Describes the components of the Cilium architecture and how these components integrate with existing architectures, such as Kubernetes.
- Installation : Details instructions for installing, configuring, and troubleshooting Cilium in different deployment modes.
- Policy Enforcement Modes : Detailed walkthrough of the policy language structure and the supported formats.
- Monitoring & Metrics : Instructions for configuring metrics collection from Cilium.
- Troubleshooting : Describes how to troubleshoot Cilium in different deployment modes.
- BPF and XDP Reference Guide : Provides a technical deep dive of BPF and XDP technology, primarily focused at developers.
- API Reference : Details the Cilium agent API for interacting with a local Cilium instance.
- Developer / Contributor Guide : Gives background to those looking to develop and contribute modifications to the Cilium code or documentation.
Introduction to Cilium¶
What is Cilium?¶
Cilium is open source software for transparently securing the network connectivity between application services deployed using Linux container management platforms like Docker and Kubernetes.
At the foundation of Cilium is a new Linux kernel technology called BPF, which enables the dynamic insertion of powerful security visibility and control logic within Linux itself. Because BPF runs inside the Linux kernel, Cilium security policies can be applied and updated without any changes to the application code or container configuration.
Why Cilium?¶
The development of modern datacenter applications has shifted to a service-oriented architecture often referred to as microservices, wherein a large application is split into small independent services that communicate with each other via APIs using lightweight protocols like HTTP. Microservices applications tend to be highly dynamic, with individual containers getting started or destroyed as the application scales out / in to adapt to load changes and during rolling updates that are deployed as part of continuous delivery.
This shift toward highly dynamic microservices presents both a challenge and an opportunity in terms of securing connectivity between microservices. Traditional Linux network security approaches (e.g., iptables) filter on IP address and TCP/UDP ports, but IP addresses frequently churn in dynamic microservices environments. The highly volatile life cycle of containers causes these approaches to struggle to scale side by side with the application as load balancing tables and access control lists carrying hundreds of thousands of rules that need to be updated with a continuously growing frequency. Protocol ports (e.g. TCP port 80 for HTTP traffic) can no longer be used to differentiate between application traffic for security purposes as the port is utilized for a wide range of messages across services.
An additional challenge is the ability to provide accurate visibility as traditional systems are using IP addresses as primary identification vehicle which may have a drastically reduced lifetime of just a few seconds in microservices architectures.
By leveraging Linux BPF, Cilium retains the ability to transparently insert security visibility + enforcement, but does so in a way that is based on service / pod / container identity (in contrast to IP address identification in traditional systems) and can filter on application-layer (e.g. HTTP). As a result, Cilium not only makes it simple to apply security policies in a highly dynamic environment by decoupling security from addressing, but can also provide stronger security isolation by operating at the HTTP-layer in addition to providing traditional Layer 3 and Layer 4 segmentation.
The use of BPF enables Cilium to achieve all of this in a way that is highly scalable even for large-scale environments.
Functionality Overview¶
Protect and secure APIs transparently¶
Ability to secure modern application protocols such as REST/HTTP, gRPC and Kafka. Traditional firewalls operates at Layer 3 and 4. A protocol running on a particular port is either completely trusted or blocked entirely. Cilium provides the ability to filter on individual application protocol requests such as:
- Allow all HTTP requests with method
GETand path/public/.*. Deny all other requests. - Allow
service1to produce on Kafka topictopic1andservice2to consume ontopic1. Reject all other Kafka messages. - Require the HTTP header
X-Token: [0-9]+to be present in all REST calls.
See the section Layer 7 Policy in our documentation for the latest list of supported protocols and examples on how to use it.
Secure service to service communication based on identities¶
Modern distributed applications rely on technologies such as application containers to facilitate agility in deployment and scale out on demand. This results in a large number of application containers to be started in a short period of time. Typical container firewalls secure workloads by filtering on source IP addresses and destination ports. This concept requires the firewalls on all servers to be manipulated whenever a container is started anywhere in the cluster.
In order to avoid this situation which limits scale, Cilium assigns a security identity to groups of application containers which share identical security policies. The identity is then associated with all network packets emitted by the application containers, allowing to validate the identity at the receiving node. Security identity management is performed using a key-value store.
Secure access to and from external services¶
Label based security is the tool of choice for cluster internal access control. In order to secure access to and from external services, traditional CIDR based security policies for both ingress and egress are supported. This allows to limit access to and from application containers to particular IP ranges.
Simple Networking¶
A simple flat Layer 3 network with the ability to span multiple clusters connects all application containers. IP allocation is kept simple by using host scope allocators. This means that each host can allocate IPs without any coordination between hosts.
The following multi node networking models are supported:
Overlay: Encapsulation based virtual network spawning all hosts. Currently VXLAN and Geneve are baked in but all encapsulation formats supported by Linux can be enabled.
When to use this mode: This mode has minimal infrastructure and integration requirements. It works on almost any network infrastructure as the only requirement is IP connectivity between hosts which is typically already given.
Native Routing: Use of the regular routing table of the Linux host. The network is required to be capable to route the IP addresses of the application containers.
When to use this mode: This mode is for advanced users and requires some awareness of the underlying networking infrastructure. This mode works well with:
- Native IPv6 networks
- In conjunction with cloud network routers
- If you are already running routing daemons
Load balancing¶
Distributed load balancing for traffic between application containers and to external services. The loadbalancing is implemented using BPF using efficient hashtables allowing for almost unlimited scale and supports direct server return (DSR) if the loadbalancing operation is not performed on the source host. Note: load balancing requires connection tracking to be enabled. This is the default.
Monitoring and Troubleshooting¶
The ability to gain visibility and to troubleshoot issues is fundamental to the
operation of any distributed system. While we learned to love tools like
tcpdump and ping and while they will always find a special place in our
hearts, we strive to provide better tooling for troubleshooting. This includes
tooling to provide:
- Event monitoring with metadata: When a packet is dropped, the tool doesn’t just report the source and destination IP of the packet, the tool provides the full label information of both the sender and receiver among a lot of other information.
- Policy decision tracing: Why is a packet being dropped or a request rejected. The policy tracing framework allows to trace the policy decision process for both, running workloads and based on arbitrary label definitions.
- Metrics export via Prometheus: Key metrics are exported via Prometheus for integration with your existing dashboards.
Integrations¶
- Network plugin integrations: CNI, libnetwork
- Container runtime events: containerd
- Kubernetes: NetworkPolicy, Labels, Ingress, Service
Getting Started Guides¶
The following is a list of guides that help you get started with Cilium. The guides cover the installation and then dive into more detailed topics such as securing clusters, connecting multiple clusters, monitoring, and troubleshooting. If you are new to Cilium it is recommended to read the Introduction to Cilium section first to learn about the basic concepts and motivation.
Installation¶
Getting Started Using Minikube¶
This guide uses minikube to demonstrate deployment and operation of Cilium in a single-node Kubernetes cluster. The minikube VM requires approximately 5GB of RAM and supports hypervisors like VirtualBox that run on Linux, macOS, and Windows.
Install kubectl & minikube¶
- Install
kubectlversion >= v1.10.0 as described in the Kubernetes Docs. - Install
minikube>= v0.33.1 as per minikube documentation: Install Minikube.
minikube version
minikube version: v0.33.1
- Create a minikube cluster:
minikube start --network-plugin=cni --memory=4096
Note that in case of installing Cilium for a specific Kubernetes version, the
--kubernetes-version vx.y.z parameter can be appended to the minikube start
command for bootstrapping the local cluster. By default, minikube will install
the most recent version of Kubernetes.
Install Cilium¶
Install Cilium as DaemonSet into your new Kubernetes cluster. The DaemonSet will automatically install itself as Kubernetes CNI plugin.
kubectl create -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.15/cilium-minikube.yaml
kubectl create -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.14/cilium-minikube.yaml
kubectl create -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.13/cilium-minikube.yaml
kubectl create -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.12/cilium-minikube.yaml
kubectl create -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.11/cilium-minikube.yaml
kubectl create -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.10/cilium-minikube.yaml
Next steps¶
Now that you have a Kubernetes cluster with Cilium up and running, you can take a couple of next steps to explore various capabilities:
Getting Started Using MicroK8s¶
This guide uses microk8s to demonstrate deployment and operation of Cilium in a single-node Kubernetes cluster. To run Cilium inside microk8s, a GNU/Linux distribution with kernel 4.9 or later is required (per the System Requirements).
Install microk8s¶
Install
microk8s>= 1.14 as per microk8s documentation: MicroK8s User guide.Enable the microk8s DNS service
microk8s.enable dns
Configure microk8s to use CNI and allow Cilium to register as that CNI:
echo "--allow-privileged" >> /var/snap/microk8s/current/args/kube-apiserver sed -i 's/--network-plugin=kubenet/--network-plugin=cni/g' /var/snap/microk8s/current/args/kubelet sed -i 's;--cni-bin-dir=${SNAP}/opt;--cni-bin-dir=/opt;g' /var/snap/microk8s/current/args/kubelet sed -i 's;bin_dir = "${SNAP}/opt;bin_dir = "/opt;g' /var/snap/microk8s/current/args/containerd-template.toml rm /var/snap/microk8s/current/args/cni-network/cni.conf curl https://raw.githubusercontent.com/cilium/cilium/v1.5/plugins/cilium-cni/05-cilium-cni.conf > /var/snap/microk8s/current/args/cni-network/05-cilium.conf systemctl restart snap.microk8s.daemon-containerd.service systemctl restart snap.microk8s.daemon-apiserver.service systemctl restart snap.microk8s.daemon-kubelet.serviceInstall or configure
kubectl.Microk8s provides a version of kubectl, so if you don’t otherwise have it installed then you can simply alias the microk8s version:
snap alias microk8s.kubectl kubectl
Alternatively, if you already have kubectl installed then you can simply point it at the microk8s version of the kubernetes API server:
export KUBECONFIG=/snap/microk8s/current/client.config
Install etcd¶
Install etcd as a StatefulSet into your new Kubernetes cluster.
kubectl create -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/addons/etcd/standalone-etcd.yaml -n kube-system
Install Cilium¶
Install Cilium as a DaemonSet into your new Kubernetes cluster. The DaemonSet will automatically install itself as Kubernetes CNI plugin.
kubectl create -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.15/cilium-microk8s.yaml
kubectl create -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.14/cilium-microk8s.yaml
kubectl create -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.13/cilium-microk8s.yaml
kubectl create -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.12/cilium-microk8s.yaml
kubectl create -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.11/cilium-microk8s.yaml
kubectl create -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.10/cilium-microk8s.yaml
Next steps¶
Now that you have a Kubernetes cluster with Cilium up and running, you can take a couple of next steps to explore various capabilities:
Self-Managed Kubernetes¶
Installation using kubeadm¶
Instructions about installing Cilium on Kubernetes cluster deployed by kubeadm are available in the official Kubernetes documentation.
Standard Installation¶
This guides takes you through the steps required to set up Cilium on Kubernetes using the cilium-etcd-operator. The cilium-etcd-operator replaces the requirement for an external kvstore. You can learn more about it in the section What is the cilium-etcd-operator? It is suitable for small and medium scale deployments where etcd performance is not absolutely essential. Please refer to the Limitations section below to learn about the exact limitations of this deployment method.
Should you encounter any issues during the installation, please refer to the
Troubleshooting section and / or seek help on the Slack channel.
Requirements¶
Make sure your Kubernetes environment is meeting the requirements:
- Kubernetes >= 1.9
- Linux kernel >= 4.9
- Kubernetes in CNI mode
- Running kube-dns/coredns (When using the etcd-operator installation method)
- Mounted BPF filesystem mounted on all worker nodes
- Enable PodCIDR allocation (
--allocate-node-cidrs) in thekube-controller-manager(recommended)
Refer to the section Requirements for detailed instruction on how to prepare your Kubernetes environment.
For CoreDNS: Enable reverse lookups¶
In order for the TLS certificates between etcd peers to work correctly, a DNS
reverse lookup on a pod IP must map back to pod name. If you are using CoreDNS,
check the CoreDNS ConfigMap and validate that in-addr.arpa and ip6.arpa
are listed as wildcards for the kubernetes block like this:
kubectl -n kube-system edit cm coredns
[...]
apiVersion: v1
data:
Corefile: |
.:53 {
errors
health
kubernetes cluster.local in-addr.arpa ip6.arpa {
pods insecure
upstream
fallthrough in-addr.arpa ip6.arpa
}
prometheus :9153
proxy . /etc/resolv.conf
cache 30
}
The contents can look different than the above. The specific configuration that
matters is to make sure that in-addr.arpa and ip6.arpa are listed as
wildcards next to cluster.local.
You can validate this by looking up a pod IP with the host utility from any
pod:
host 10.60.20.86
86.20.60.10.in-addr.arpa domain name pointer cilium-etcd-972nprv9dp.cilium-etcd.kube-system.svc.cluster.local.
Deploy Cilium + cilium-etcd-operator¶
The following all-in-one YAML will deploy all required components to bring up Cilium including an etcd cluster managed by the cilium-etcd-operator.
Note
It is important to always deploy Cilium and the cilium-etcd-operator together. The cilium-etcd-operator is not able to bootstrap without running Cilium instances. It requires a CNI plugin to provide networking between the etcd pods forming the cluster. Cilium has special logic built in that allows etcd pods to communicate during the bootstrapping phase of Cilium.
kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.15/cilium.yaml
kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.14/cilium.yaml
kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.13/cilium.yaml
kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.12/cilium.yaml
kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.11/cilium.yaml
kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.10/cilium.yaml
kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.15/cilium-crio.yaml
kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.14/cilium-crio.yaml
kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.13/cilium-crio.yaml
kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.12/cilium-crio.yaml
kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.11/cilium-crio.yaml
kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.10/cilium-crio.yaml
kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.15/cilium-containerd.yaml
kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.14/cilium-containerd.yaml
kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.13/cilium-containerd.yaml
kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.12/cilium-containerd.yaml
kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.11/cilium-containerd.yaml
kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.10/cilium-containerd.yaml
Validate the Installation¶
You can monitor as Cilium and all required components are being installed:
kubectl -n kube-system get pods --watch
NAME READY STATUS RESTARTS AGE
cilium-etcd-operator-6ffbd46df9-pn6cf 1/1 Running 0 7s
cilium-operator-cb4578bc5-q52qk 0/1 Pending 0 8s
cilium-s8w5m 0/1 PodInitializing 0 7s
coredns-86c58d9df4-4g7dd 0/1 ContainerCreating 0 8m57s
coredns-86c58d9df4-4l6b2 0/1 ContainerCreating 0 8m57s
It may take a couple of minutes for the etcd-operator to bring up the necessary number of etcd pods to achieve quorum. Once it reaches quorum, all components should be healthy and ready:
cilium-etcd-8d95ggpjmw 1/1 Running 0 78s
cilium-etcd-operator-6ffbd46df9-pn6cf 1/1 Running 0 4m12s
cilium-etcd-t695lgxf4x 1/1 Running 0 118s
cilium-etcd-zw285m6t9g 1/1 Running 0 2m41s
cilium-operator-cb4578bc5-q52qk 1/1 Running 0 4m13s
cilium-s8w5m 1/1 Running 0 4m12s
coredns-86c58d9df4-4g7dd 1/1 Running 0 13m
coredns-86c58d9df4-4l6b2 1/1 Running 0 13m
etcd-operator-5cf67779fd-hd9j7 1/1 Running 0 2m42s
Troubleshooting¶
Make sure that
kube-dnsorcorednsis running and healthy in thekube-systemnamespace. A functioning Kubernetes DNS is strictly required in order for Cilium to resolve the ClusterIP of the etcd cluster. If eitherkube-dnsorcorednswere already running before Cilium was deployed, the pods may be managed by a former CNI plugin.cilium-operatorwill automatically restart the pods to ensure that they are being managed by the Cilium CNI plugin. You can manually restart the pods as well if required and validate that Cilium is managingkube-dnsorcorednsby running:kubectl -n kube-system get cepYou should see
kube-dns-xxxorcoredns-xxxpods.In order for the entire system to come up, the following components have to be running at the same time:
kube-dnsorcorednscilium-xxxcilium-etcd-operatoretcd-operatoretcd-xxxAll timeouts are configured that this will typically work out smoothly even if some of the pods restart once or twice. In case any of the above pods get into a long
CrashLoopBackoff, bootstrapping can be expedited by restarting the pods to reset theCrashLoopBackofftime.
What is the cilium-etcd-operator?¶
The cilium-etcd-operator uses and extends the etcd-operator to guarantee quorum, auto-create certificates, and manage compaction:
- Automatic re-creation of the etcd cluster when the cluster loses quorum. The standard etcd-operator will refuse to bring up new etcd nodes and the etcd cluster becomes unusable.
- Automatic creation of certificates and keys. This simplifies the installation of the operator and makes the certificates and keys required to access the etcd cluster available to Cilium using a well known Kubernetes secret name.
- Compaction is automatically handled.
Limitations¶
Use of the cilium-etcd-operator offers a lot of advantages including simplicity of installation, automatic management of the etcd cluster including compaction, restart on quorum loss, and automatic use of TLS. There are several disadvantages which can become of relevance as you scale up your clusters:
- etcd nodes operated by the etcd-operator will not use persistent storage. Once the etcd cluster looses quorum, the etcd cluster is automatically re-created by the cilium-etcd-operator. Cilium will automatically recover and re-create all state in etcd. This operation can take can couple of seconds and may cause minor disruptions as ongoing distributed locks are invalidated and security identities have to be re-allocated.
- etcd is very sensitive to disk IO latency and requires fast disk access at a certain scale. The cilium-etcd-operator will not take any measures to provide fast disk access and performance will depend whatever is provided to the pods in your Kubernetes cluster. See etcd Hardware recommendations for more details.
Installation with external etcd¶
This guide walks you through the steps required to set up Cilium on Kubernetes using an external etcd. Use of an external etcd provides better performance and is suitable for larger environments. If you are looking for a simple installation method to get started, refer to the section Standard Installation.
Should you encounter any issues during the installation, please refer to the Troubleshooting section and / or seek help on Slack.
Requirements¶
Make sure your Kubernetes environment is meeting the requirements:
- Kubernetes >= 1.9
- Linux kernel >= 4.9
- Kubernetes in CNI mode
- Running kube-dns/coredns (When using the etcd-operator installation method)
- Mounted BPF filesystem mounted on all worker nodes
- Enable PodCIDR allocation (
--allocate-node-cidrs) in thekube-controller-manager(recommended)
Refer to the section Requirements for detailed instruction on how to prepare your Kubernetes environment.
Configure the External Etcd¶
When using an external kvstore, the address of the external kvstore needs to be configured in the ConfigMap. Download the base YAML for the version of Kubernetes you are using:
wget https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.15/cilium-external-etcd.yaml
wget https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.14/cilium-external-etcd.yaml
wget https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.13/cilium-external-etcd.yaml
wget https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.12/cilium-external-etcd.yaml
wget https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.11/cilium-external-etcd.yaml
wget https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.10/cilium-external-etcd.yaml
- Open
cilium-external-etcd.yamland find thecilium-configConfigMap and edit theendpoints:to include the list of all your etcd endpoints or a service IP that will load-balance to all etcd endpoints.
etcd-config: |-
---
endpoints:
- https://etcd1.deathstar.empire:2379
- https://etcd2.deathstar.empire:2379
- https://etcd3.deathstar.empire:2379
- Create a Kubernetes secret with the root certificate authority, and client-side key and certificate of etcd:
kubectl create secret generic -n kube-system cilium-etcd-secrets \
--from-file=etcd-client-ca.crt=ca.crt \
--from-file=etcd-client.key=client.key \
--from-file=etcd-client.crt=client.crt
- In case you are not using a TLS-enabled etcd, comment out the configuration options in the ConfigMap referring to the key locations like this:
# In case you want to use TLS in etcd, uncomment the 'ca-file' line
# and create a kubernetes secret by following the tutorial in
# https://cilium.link/etcd-config
#ca-file: '/var/lib/etcd-secrets/etcd-client-ca.crt'
#
# In case you want client to server authentication, uncomment the following
# lines and create a kubernetes secret by following the tutorial in
# https://cilium.link/etcd-config
#key-file: '/var/lib/etcd-secrets/etcd-client.key'
#cert-file: '/var/lib/etcd-secrets/etcd-client.crt'
Deploy Cilium¶
kubectl create -f cilium-external-etcd.yaml
Validate the Installation¶
Verify that Cilium pods were started on each of your worker nodes
kubectl --namespace kube-system get ds cilium
NAME DESIRED CURRENT READY NODE-SELECTOR AGE
cilium 4 4 4 <none> 2m
kubectl -n kube-system get deployments cilium-operator
NAME READY UP-TO-DATE AVAILABLE AGE
cilium-operator 1/1 1 1 5m25s
Managed Kubernetes¶
The following guides cover the installation steps for managed Kubernetes environments as offered by cloud providers. If a particular offering is not covered, the guide Standard Installation has a good chance of working out of the box as well.
Installation on AWS EKS¶
Create an EKS Cluster¶
The first step is to create an EKS cluster. This guide will use eksctl but you can also follow the Getting Started with Amazon EKS guide.
Ensure your AWS credentials are located in ~/.aws/credentials or are stored
as environment variables .
Next, install eksctl :
curl --silent --location "https://github.com/weaveworks/eksctl/releases/download/latest_release/eksctl_$(uname -s)_amd64.tar.gz" | tar xz -C /tmp
sudo mv /tmp/eksctl /usr/local/bin
brew install weaveworks/tap/eksctl
Ensure that aws-iam-authenticator is installed and in the executable path:
which aws-iam-authenticator
If not, install it based on the AWS IAM authenticator documentation .
Create an EKS cluster with eksctl see the eksctl Documentation for details on how to set credentials,
change region, VPC, cluster size, etc.
eksctl create cluster
You should see something like this:
[ℹ] using region us-west-2 [ℹ] setting availability zones to [us-west-2b us-west-2a us-west-2c] [ℹ] subnets for us-west-2b - public:192.168.0.0/19 private:192.168.96.0/19 [ℹ] subnets for us-west-2a - public:192.168.32.0/19 private:192.168.128.0/19 [ℹ] subnets for us-west-2c - public:192.168.64.0/19 private:192.168.160.0/19 [ℹ] nodegroup "ng-1e83ec43" will use "ami-0a2abab4107669c1b" [AmazonLinux2/1.11] [ℹ] creating EKS cluster "ridiculous-gopher-1548608219" in "us-west-2" region [ℹ] will create 2 separate CloudFormation stacks for cluster itself and the initial nodegroup [ℹ] if you encounter any issues, check CloudFormation console or try 'eksctl utils describe-stacks --region=us-west-2 --name=ridiculous-gopher-1548608219' [ℹ] creating cluster stack "eksctl-ridiculous-gopher-1548608219-cluster" [ℹ] creating nodegroup stack "eksctl-ridiculous-gopher-1548608219-nodegroup-ng-1e83ec43" [✔] all EKS cluster resource for "ridiculous-gopher-1548608219" had been created [✔] saved kubeconfig as "/Users/tgraf/.kube/config" [ℹ] nodegroup "ng-1e83ec43" has 0 node(s) [ℹ] waiting for at least 2 node(s) to become ready in "ng-1e83ec43" [ℹ] nodegroup "ng-1e83ec43" has 2 node(s) [ℹ] node "ip-192-168-4-64.us-west-2.compute.internal" is ready [ℹ] node "ip-192-168-42-60.us-west-2.compute.internal" is ready [ℹ] kubectl command should work with "/Users/tgraf/.kube/config", try 'kubectl get nodes' [✔] EKS cluster "ridiculous-gopher-1548608219" in "us-west-2" region is ready
Disable SNAT in aws-node agent¶
Disable the SNAT behavior of the aws-node DaemonSet which causes all traffic leaving a node to be automatically be masqueraded.
kubectl -n kube-system set env ds aws-node AWS_VPC_K8S_CNI_EXTERNALSNAT=true
Prepare the nodes for Cilium¶
Deploy the following DaemonSet to prepare all EKS nodes for Cilium:
kubectl -n kube-system apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/node-init/eks-node-init.yaml
This will mount the BPF filesystem and ensures that the filesystem is automatically mounted when the node is rebooted. Due to being a DaemonSet, any new node added to the cluster will automatically get initialized as well.
For CoreDNS: Enable reverse lookups¶
In order for the TLS certificates between etcd peers to work correctly, a DNS
reverse lookup on a pod IP must map back to pod name. If you are using CoreDNS,
check the CoreDNS ConfigMap and validate that in-addr.arpa and ip6.arpa
are listed as wildcards for the kubernetes block like this:
kubectl -n kube-system edit cm coredns
[...]
apiVersion: v1
data:
Corefile: |
.:53 {
errors
health
kubernetes cluster.local in-addr.arpa ip6.arpa {
pods insecure
upstream
fallthrough in-addr.arpa ip6.arpa
}
prometheus :9153
proxy . /etc/resolv.conf
cache 30
}
The contents can look different than the above. The specific configuration that
matters is to make sure that in-addr.arpa and ip6.arpa are listed as
wildcards next to cluster.local.
You can validate this by looking up a pod IP with the host utility from any
pod:
host 10.60.20.86
86.20.60.10.in-addr.arpa domain name pointer cilium-etcd-972nprv9dp.cilium-etcd.kube-system.svc.cluster.local.
Deploy Cilium + cilium-etcd-operator¶
The following all-in-one YAML will deploy all required components to bring up Cilium including an etcd cluster managed by the cilium-etcd-operator.
Note
It is important to always deploy Cilium and the cilium-etcd-operator together. The cilium-etcd-operator is not able to bootstrap without running Cilium instances. It requires a CNI plugin to provide networking between the etcd pods forming the cluster. Cilium has special logic built in that allows etcd pods to communicate during the bootstrapping phase of Cilium.
kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.15/cilium.yaml
kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.14/cilium.yaml
kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.13/cilium.yaml
kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.12/cilium.yaml
kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.11/cilium.yaml
kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.10/cilium.yaml
kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.15/cilium-crio.yaml
kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.14/cilium-crio.yaml
kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.13/cilium-crio.yaml
kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.12/cilium-crio.yaml
kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.11/cilium-crio.yaml
kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.10/cilium-crio.yaml
kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.15/cilium-containerd.yaml
kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.14/cilium-containerd.yaml
kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.13/cilium-containerd.yaml
kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.12/cilium-containerd.yaml
kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.11/cilium-containerd.yaml
kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.10/cilium-containerd.yaml
Note
You may notice that the kube-dns-* pods get restarted. The
cilium-operator will automatically restart CoreDNS if the pods are not
managed by the Cilium CNI plugin.
Validate the Installation¶
You can monitor as Cilium and all required components are being installed:
kubectl -n kube-system get pods --watch
NAME READY STATUS RESTARTS AGE
aws-node-vgc7n 1/1 Running 0 2m55s
aws-node-x6sjm 1/1 Running 0 3m35s
cilium-cvp8q 0/1 Init:0/1 0 53s
cilium-etcd-operator-6d9975f5df-2vflw 0/1 ContainerCreating 0 54s
cilium-operator-788c55554-gkpbf 0/1 ContainerCreating 0 54s
cilium-tdzcx 0/1 Init:0/1 0 53s
coredns-77b578f78d-km6r4 1/1 Running 0 11m
coredns-77b578f78d-qr6gq 1/1 Running 0 11m
kube-proxy-l47rx 1/1 Running 0 6m28s
kube-proxy-zj6v5 1/1 Running 0 6m28s
It may take a couple of minutes for the etcd-operator to bring up the necessary number of etcd pods to achieve quorum. Once it reaches quorum, all components should be healthy and ready:
kubectl -n=kube-system get pods
NAME READY STATUS RESTARTS AGE
aws-node-vgc7n 1/1 Running 0 2m
aws-node-x6sjm 1/1 Running 0 3m
cilium-cvp8q 1/1 Running 0 42s
cilium-etcd-operator-6d9975f5df-2vflw 1/1 Running 0 43s
cilium-etcd-p2ggsb22nc 1/1 Running 0 28s
cilium-operator-788c55554-gkpbf 1/1 Running 2 43s
cilium-tdzcx 1/1 Running 0 42s
coredns-77b578f78d-2khwp 1/1 Running 0 13s
coredns-77b578f78d-bs6rp 1/1 Running 0 13s
etcd-operator-7b9768bc99-294wf 1/1 Running 0 37s
kube-proxy-l47rx 1/1 Running 0 6m
kube-proxy-zj6v5 1/1 Running 0 6m
Installation on Google GKE¶
GKE Requirements¶
- Install the Google Cloud SDK (
gcloud) see [Installing Google Cloud SDK](https://cloud.google.com/sdk/install) - Create a project or use an existing one
export GKE_PROJECT=gke-clusters
gcloud projects create $GKE_PROJECT
- Enable the GKE API for the project if not already done
gcloud services enable --project $GKE_PROJECT container.googleapis.com
Create a GKE Cluster¶
You can apply any method to create a GKE cluster. The example given here is
using the Google Cloud SDK. This guide
will create a cluster on zone europe-west4-a; feel free to change the zone
if you are in a different region of the globe.
export GKE_ZONE="europe-west4-a"
gcloud container --project $GKE_PROJECT clusters create cluster1 \
--username "admin" --image-type COS --num-nodes 2 --zone ${GKE_ZONE}
When done, you should be able to access your cluster like this:
kubectl get nodes
NAME STATUS ROLES AGE VERSION
gke-cluster1-default-pool-a63a765c-flr2 Ready <none> 6m v1.11.7-gke.4
gke-cluster1-default-pool-a63a765c-z73c Ready <none> 6m v1.11.7-gke.4
Create a cluster-admin-binding¶
kubectl create clusterrolebinding cluster-admin-binding --clusterrole cluster-admin --user your@google.email
Prepare the Cluster Nodes¶
By deploying the cilium-node-init DaemonSet, GKE worker nodes are
automatically prepared to run Cilium as they are added to the cluster. The
DaemonSet will:
- Mount the BPF filesystem
- Enable kubelet to operate in CNI mode
- Install the Cilium CNI configuration file
kubectl create namespace cilium kubectl -n cilium apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/node-init/node-init.yaml
Restart kube-dns¶
kube-dns is already running but is still managed by the original GKE network plugin. Restart kube-dns to ensure it is managed by Cilium.
kubectl -n kube-system delete pod -l k8s-app=kube-dns
Deploy Cilium + cilium-etcd-operator¶
The following all-in-one YAML will deploy all required components to bring up Cilium including an etcd cluster managed by the cilium-etcd-operator.
kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.15/cilium-with-node-init.yaml
kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.14/cilium-with-node-init.yaml
kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.13/cilium-with-node-init.yaml
kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.12/cilium-with-node-init.yaml
kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.11/cilium-with-node-init.yaml
kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.10/cilium-with-node-init.yaml
Restart remaining pods¶
Once Cilium is up and running, restart all pods in kube-system so they can
be managed by Cilium, similar to the steps that we have previously performed
for kube-dns
$ kubectl delete pods -n kube-system $(kubectl get pods -n kube-system -o custom-columns=NAME:.metadata.name,HOSTNETWORK:.spec.hostNetwork --no-headers=true | grep '<none>' | awk '{ print $1 }')
pod "event-exporter-v0.2.3-f9c896d75-cbvcz" deleted
pod "fluentd-gcp-scaler-69d79984cb-nfwwk" deleted
pod "heapster-v1.6.0-beta.1-56d5d5d87f-qw8pv" deleted
pod "kube-dns-5f8689dbc9-2nzft" deleted
pod "kube-dns-5f8689dbc9-j7x5f" deleted
pod "kube-dns-autoscaler-76fcd5f658-22r72" deleted
pod "kube-state-metrics-7d9774bbd5-n6m5k" deleted
pod "l7-default-backend-6f8697844f-d2rq2" deleted
pod "metrics-server-v0.3.1-54699c9cc8-7l5w2" deleted
Installer Integrations¶
The following list includes the Kubernetes installer integrations we are aware of. If your preferred installer is not in the list, you can always fall back to the standard Standard Installation guide which works independently any installer.
Installation using Kops¶
As of kops 1.9 release, Cilium can be plugged into kops-deployed
clusters as the CNI plugin. This guide provides steps to create a Kubernetes
cluster on AWS using kops and Cilium as the CNI plugin. Note, the kops
deployment will automate several deployment features in AWS by default,
including AutoScaling, Volumes, VPCs, etc.
Prerequisites¶
Installing kops¶
curl -LO https://github.com/kubernetes/kops/releases/download/$(curl -s https://api.github.com/repos/kubernetes/kops/releases/latest | grep tag_name | cut -d '"' -f 4)/kops-linux-amd64
chmod +x kops-linux-amd64
sudo mv kops-linux-amd64 /usr/local/bin/kops
brew update && brew install kops
Setting up IAM Group and User¶
Assuming you have all the prerequisites, run the following commands to create
the kops user and group:
# Create IAM group named kops and grant access
aws iam create-group --group-name kops
aws iam attach-group-policy --policy-arn arn:aws:iam::aws:policy/AmazonEC2FullAccess --group-name kops
aws iam attach-group-policy --policy-arn arn:aws:iam::aws:policy/AmazonRoute53FullAccess --group-name kops
aws iam attach-group-policy --policy-arn arn:aws:iam::aws:policy/AmazonS3FullAccess --group-name kops
aws iam attach-group-policy --policy-arn arn:aws:iam::aws:policy/IAMFullAccess --group-name kops
aws iam attach-group-policy --policy-arn arn:aws:iam::aws:policy/AmazonVPCFullAccess --group-name kops
aws iam create-user --user-name kops
aws iam add-user-to-group --user-name kops --group-name kops
aws iam create-access-key --user-name kops
kops requires the creation of a dedicated S3 bucket in order to store the
state and representation of the cluster. You will need to change the bucket
name and provide your unique bucket name (for example a reverse of FQDN added
with short description of the cluster). Also make sure to use the region where
you will be deploying the cluster.
aws s3api create-bucket --bucket prefix-example-com-state-store --region us-west-2 --create-bucket-configuration LocationConstraint=us-west-2
export KOPS_STATE_STORE=s3://prefix-example-com-state-store
The above steps are sufficient for getting a working cluster installed. Please consult kops aws documentation for more detailed setup instructions.
Cilium Prerequisites¶
- Ensure the System Requirements are met, particularly the Linux kernel and key-value store versions.
In this guide, we will use etcd version 3.1.11 and the latest CoreOS stable
image which satisfies the minimum kernel version requirement of Cilium. To get
the latest CoreOS ami image, you can change the region value to your choice
in the command below.
aws ec2 describe-images --region=us-west-2 --owner=595879546273 --filters "Name=virtualization-type,Values=hvm" "Name=name,Values=CoreOS-stable*" --query 'sort_by(Images,&CreationDate)[-1].{id:ImageLocation}'
{
"id": "595879546273/CoreOS-stable-1745.5.0-hvm"
}
Creating a Cluster¶
- Note that you will need to specify the
--master-zonesand--zonesfor creating the master and worker nodes. The number of master zones should be * odd (1, 3, …) for HA. For simplicity, you can just use 1 region. - The cluster
NAMEvariable should end withk8s.localto use the gossip protocol. If creating multiple clusters using the same kops user, then make the cluster name unique by adding a prefix such ascom-company-emailid-.
export NAME=com-company-emailid-cilium.k8s.local
export KOPS_FEATURE_FLAGS=SpecOverrideFlag
kops create cluster --state=${KOPS_STATE_STORE} --node-count 3 --node-size t2.medium --master-size t2.medium --topology private --master-zones us-west-2a,us-west-2b,us-west-2c --zones us-west-2a,us-west-2b,us-west-2c --image 595879546273/CoreOS-stable-1745.5.0-hvm --networking cilium --override "cluster.spec.etcdClusters[*].version=3.1.11" --kubernetes-version 1.10.3 --cloud-labels "Team=Dev,Owner=Admin" ${NAME}
You may be prompted to create a ssh public-private key pair.
ssh-keygen
(Please see Deleting a Cluster)
Testing Cilium¶
Follow the Cilium getting started guide example to test that the cluster is setup properly and that Cilium CNI and security policies are functional.
Deleting a Cluster¶
To undo the dependencies and other deployment features in AWS from the kops
cluster creation, use kops to destroy a cluster immediately with the
parameter --yes:
kops delete cluster ${NAME} --yes
Appendix: Details of kops flags used in cluster creation¶
The following section explains all the flags used in create cluster command.
KOPS_FEATURE_FLAGS=SpecOverrideFlag: This flag is used to override the etcd version to be used from 2.X[kops default ] to 3.1.x [requirement of cilium]--state=${KOPS_STATE_STORE}: KOPS uses an S3 bucket to store the state of your cluster and representation of your cluster--node-count 3: No. of worker nodes in the kubernetes cluster.--node-size t2.medium: The size of the AWS EC2 instance for worker nodes--master-size t2.medium: The size of the AWS EC2 instance of master nodes--topology private: Cluster will be created with private topology, what that means is all masters/nodes will be launched in a private subnet in the VPC--master-zones eu-west-1a,eu-west-1b,eu-west-1c: The 3 zones ensure the HA of master nodes, each belonging in a different Availability zones.--zones eu-west-1a,eu-west-1b,eu-west-1c: Zones where the worker nodes will be deployed--image 595879546273/CoreOS-stable-1745.3.1-hvm: Image name to be deployed (Cilium requires kernel version 4.8 and above so ensure to use the right OS for workers.)--networking cilium: Networking CNI plugin to be used - cilium--override "cluster.spec.etcdClusters[*].version=3.1.11": Overrides the etcd version to be used.--kubernetes-version 1.10.3: Kubernetes version that is to be installed. Please note [Kops 1.9 officially supports k8s version 1.9]--cloud-labels "Team=Dev,Owner=Admin": Labels for your cluster${NAME}: Name of the cluster. Make sure the name ends with k8s.local for a gossip based cluster
Installation using Kubespray¶
The guide is to use Kubespray for creating an AWS Kubernetes cluster running Cilium as the CNI. The guide uses:
- Kubespray v2.6.0
- Latest Cilium released version (instructions for using the version are mentioned below)
Please consult Kubespray Prerequisites and Cilium System Requirements.
Installing Kubespray¶
$ git clone --branch v2.6.0 https://github.com/kubernetes-incubator/kubespray
Install dependencies from requirements.txt
$ cd kubespray
$ sudo pip install -r requirements.txt
Infrastructure Provisioning¶
We will use Terraform for provisioning AWS infrastructure.
Export the variables for your AWS credentials
export AWS_ACCESS_KEY_ID="www"
export AWS_SECRET_ACCESS_KEY ="xxx"
export AWS_SSH_KEY_NAME="yyy"
export AWS_DEFAULT_REGION="zzz"
We will start by specifying the infrastructure needed for the Kubernetes cluster.
$ cd contrib/terraform/aws
$ cp contrib/terraform/aws/terraform.tfvars.example terraform.tfvars`
Open the file and change any defaults particularly, the number of master, etcd, and worker nodes. You can change the master and etcd number to 1 for deployments that don’t need high availability. By default, this tutorial will create:
- VPC with 2 public and private subnets
- Bastion Hosts and NAT Gateways in the Public Subnet
- Three of each (masters, etcd, and worker nodes) in the Private Subnet
- AWS ELB in the Public Subnet for accessing the Kubernetes API from the internet
- Terraform scripts using
CoreOSas base image.
Example terraform.tfvars file:
#Global Vars
aws_cluster_name = "kubespray"
#VPC Vars
aws_vpc_cidr_block = "XXX.XXX.192.0/18"
aws_cidr_subnets_private = ["XXX.XXX.192.0/20","XXX.XXX.208.0/20"]
aws_cidr_subnets_public = ["XXX.XXX.224.0/20","XXX.XXX.240.0/20"]
#Bastion Host
aws_bastion_size = "t2.medium"
#Kubernetes Cluster
aws_kube_master_num = 3
aws_kube_master_size = "t2.medium"
aws_etcd_num = 3
aws_etcd_size = "t2.medium"
aws_kube_worker_num = 3
aws_kube_worker_size = "t2.medium"
#Settings AWS ELB
aws_elb_api_port = 6443
k8s_secure_api_port = 6443
kube_insecure_apiserver_address = "0.0.0.0"
terraform init to initialize the following modules
module.aws-vpcmodule.aws-elbmodule.aws-iam
$ terraform init
Once initialized , execute:
$ terraform plan -out=aws_kubespray_plan
This will generate a file, aws_kubespray_plan, depicting an execution
plan of the infrastructure that will be created on AWS. To apply, execute:
$ terraform init
$ terraform apply "aws_kubespray_plan"
Terraform automatically creates an Ansible Inventory file at inventory/hosts.
Installing Kubernetes cluster with Cilium as CNI¶
Kubespray uses Ansible as its substrate for provisioning and orchestration. Once the infrastructure is created, you can run the Ansible playbook to install Kubernetes and all the required dependencies. Execute the below command in the kubespray clone repo, providing the correct path of the AWS EC2 ssh private key in ansible_ssh_private_key_file=<path to EC2 SSH private key file>
We recommend using the latest released Cilium version by editing roles/download/defaults/main.yml. Open the file, search for cilium_version, and replace the version with the latest released. As an example, the updated version entry will look like: cilium_version: "v1.2.0".
$ ansible-playbook -i ./inventory/hosts ./cluster.yml -e ansible_user=core -e bootstrap_os=coreos -e kube_network_plugin=cilium -b --become-user=root --flush-cache -e ansible_ssh_private_key_file=<path to EC2 SSH private key file>
Validate Cluster¶
To check if cluster is created successfully, ssh into the bastion host with the user core.
# Get information about the basiton host
$ cat ssh-bastion.conf
$ ssh -i ~/path/to/ec2-key-file.pem core@public_ip_of_bastion_host
Execute the commands below from the bastion host. If kubectl isn’t installed on the bastion host, you can login to the master node to test the below commands. You may need to copy the private key to the bastion host to access the master node.
$ kubectl get nodes
$ kubectl get pods -n kube-system
You should see that nodes are in Ready state and Cilium pods are in Running state
Demo Application¶
Follow this link to deploy a demo application and verify the correctness of the installation.
Delete Cluster¶
$ cd contrib/terraform/aws
$ terraform destroy
External Guides¶
Security Tutorials¶
HTTP/REST API call authorization¶
If you haven’t read the Introduction to Cilium yet, we’d encourage you to do that first.
The best way to get help if you get stuck is to ask a question on the Cilium Slack channel. With Cilium contributors across the globe, there is almost always someone available to help.
Setup Cilium¶
If you have not set up Cilium yet, pick any installation method as described in section Installation to set up Cilium for your Kubernetes environment. If in doubt, pick Getting Started Using Minikube as the simplest way to set up a Kubernetes cluster with Cilium.
Deploy the Demo Application¶
Now that we have Cilium deployed and kube-dns operating correctly we can deploy our demo application.
In our Star Wars-inspired example, there are three microservices applications: deathstar, tiefighter, and xwing. The deathstar runs an HTTP webservice on port 80, which is exposed as a Kubernetes Service to load-balance requests to deathstar across two pod replicas. The deathstar service provides landing services to the empire’s spaceships so that they can request a landing port. The tiefighter pod represents a landing-request client service on a typical empire ship and xwing represents a similar service on an alliance ship. They exist so that we can test different security policies for access control to deathstar landing services.
Application Topology for Cilium and Kubernetes
The file http-sw-app.yaml contains a Kubernetes Deployment for each of the three services.
Each deployment is identified using the Kubernetes labels (org=empire, class=deathstar), (org=empire, class=tiefighter),
and (org=alliance, class=xwing).
It also includes a deathstar-service, which load-balances traffic to all pods with label (org=empire, class=deathstar).
$ kubectl create -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/minikube/http-sw-app.yaml service/deathstar created deployment.extensions/deathstar created pod/tiefighter created pod/xwing created
Kubernetes will deploy the pods and service in the background. Running
kubectl get pods,svc will inform you about the progress of the operation.
Each pod will go through several states until it reaches Running at which
point the pod is ready.
$ kubectl get pods,svc
NAME READY STATUS RESTARTS AGE
pod/deathstar-6fb5694d48-5hmds 1/1 Running 0 107s
pod/deathstar-6fb5694d48-fhf65 1/1 Running 0 107s
pod/tiefighter 1/1 Running 0 107s
pod/xwing 1/1 Running 0 107s
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/deathstar ClusterIP 10.96.110.8 <none> 80/TCP 107s
service/kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 3m53s
Each pod will be represented in Cilium as an Endpoint. We can invoke the
cilium tool inside the Cilium pod to list them:
$ kubectl -n kube-system get pods -l k8s-app=cilium
NAME READY STATUS RESTARTS AGE
cilium-5ngzd 1/1 Running 0 3m19s
$ kubectl -n kube-system exec cilium-1c2cz -- cilium endpoint list
ENDPOINT POLICY (ingress) POLICY (egress) IDENTITY LABELS (source:key[=value]) IPv6 IPv4 STATUS
ENFORCEMENT ENFORCEMENT
108 Disabled Disabled 104 k8s:io.cilium.k8s.policy.cluster=default 10.15.233.139 ready
k8s:io.cilium.k8s.policy.serviceaccount=coredns
k8s:io.kubernetes.pod.namespace=kube-system
k8s:k8s-app=kube-dns
1011 Disabled Disabled 104 k8s:io.cilium.k8s.policy.cluster=default 10.15.96.117 ready
k8s:io.cilium.k8s.policy.serviceaccount=coredns
k8s:io.kubernetes.pod.namespace=kube-system
k8s:k8s-app=kube-dns
2407 Disabled Disabled 22839 k8s:class=deathstar 10.15.129.95 ready
k8s:io.cilium.k8s.policy.cluster=default
k8s:io.cilium.k8s.policy.serviceaccount=default
k8s:io.kubernetes.pod.namespace=default
k8s:org=empire
2607 Disabled Disabled 4 reserved:health 10.15.28.196 ready
3339 Disabled Disabled 22839 k8s:class=deathstar 10.15.72.39 ready
k8s:io.cilium.k8s.policy.cluster=default
k8s:io.cilium.k8s.policy.serviceaccount=default
k8s:io.kubernetes.pod.namespace=default
k8s:org=empire
3738 Disabled Disabled 47764 k8s:class=xwing 10.15.116.85 ready
k8s:io.cilium.k8s.policy.cluster=default
k8s:io.cilium.k8s.policy.serviceaccount=default
k8s:io.kubernetes.pod.namespace=default
k8s:org=alliance
3837 Disabled Disabled 9164 k8s:class=tiefighter 10.15.22.126 ready
k8s:io.cilium.k8s.policy.cluster=default
k8s:io.cilium.k8s.policy.serviceaccount=default
k8s:io.kubernetes.pod.namespace=default
k8s:org=empire
Both ingress and egress policy enforcement is still disabled on all of these pods because no network policy has been imported yet which select any of the pods.
Check Current Access¶
From the perspective of the deathstar service, only the ships with label org=empire are allowed to connect and request landing. Since we have no rules enforced, both xwing and tiefighter will be able to request landing. To test this, use the commands below.
$ kubectl exec xwing -- curl -s -XPOST deathstar.default.svc.cluster.local/v1/request-landing
Ship landed
$ kubectl exec tiefighter -- curl -s -XPOST deathstar.default.svc.cluster.local/v1/request-landing
Ship landed
Apply an L3/L4 Policy¶
When using Cilium, endpoint IP addresses are irrelevant when defining security policies. Instead, you can use the labels assigned to the pods to define security policies. The policies will be applied to the right pods based on the labels irrespective of where or when it is running within the cluster.
We’ll start with the basic policy restricting deathstar landing requests to only the ships that have label (org=empire). This will not allow any ships that don’t have the org=empire label to even connect with the deathstar service.
This is a simple policy that filters only on IP protocol (network layer 3) and TCP protocol (network layer 4), so it is often referred to as an L3/L4 network security policy.
Note: Cilium performs stateful connection tracking, meaning that if policy allows the frontend to reach backend, it will automatically allow all required reply packets that are part of backend replying to frontend within the context of the same TCP/UDP connection.
L4 Policy with Cilium and Kubernetes
We can achieve that with the following CiliumNetworkPolicy:
apiVersion: "cilium.io/v2"
kind: CiliumNetworkPolicy
description: "L3-L4 policy to restrict deathstar access to empire ships only"
metadata:
name: "rule1"
spec:
endpointSelector:
matchLabels:
org: empire
class: deathstar
ingress:
- fromEndpoints:
- matchLabels:
org: empire
toPorts:
- ports:
- port: "80"
protocol: TCP
CiliumNetworkPolicies match on pod labels using an “endpointSelector” to identify the sources and destinations to which the policy applies.
The above policy whitelists traffic sent from any pods with label (org=empire) to deathstar pods with label (org=empire, class=deathstar) on TCP port 80.
To apply this L3/L4 policy, run:
$ kubectl create -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/minikube/sw_l3_l4_policy.yaml ciliumnetworkpolicy.cilium.io/rule1 created
Now if we run the landing requests again, only the tiefighter pods with the label org=empire will succeed. The xwing pods will be blocked!
$ kubectl exec tiefighter -- curl -s -XPOST deathstar.default.svc.cluster.local/v1/request-landing
Ship landed
This works as expected. Now the same request run from an xwing pod will fail:
$ kubectl exec xwing -- curl -s -XPOST deathstar.default.svc.cluster.local/v1/request-landing
This request will hang, so press Control-C to kill the curl request, or wait for it to time out.
Inspecting the Policy¶
If we run cilium endpoint list again we will see that the pods with the label org=empire and class=deathstar now have ingress policy enforcement enabled as per the policy above.
$ kubectl -n kube-system exec cilium-1c2cz -- cilium endpoint list
ENDPOINT POLICY (ingress) POLICY (egress) IDENTITY LABELS (source:key[=value]) IPv6 IPv4 STATUS
ENFORCEMENT ENFORCEMENT
108 Disabled Disabled 104 k8s:io.cilium.k8s.policy.cluster=default 10.15.233.139 ready
k8s:io.cilium.k8s.policy.serviceaccount=coredns
k8s:io.kubernetes.pod.namespace=kube-system
k8s:k8s-app=kube-dns
1011 Disabled Disabled 104 k8s:io.cilium.k8s.policy.cluster=default 10.15.96.117 ready
k8s:io.cilium.k8s.policy.serviceaccount=coredns
k8s:io.kubernetes.pod.namespace=kube-system
k8s:k8s-app=kube-dns
1518 Disabled Disabled 4 reserved:health 10.15.28.196 ready
2407 Enabled Disabled 22839 k8s:class=deathstar 10.15.129.95 ready
k8s:io.cilium.k8s.policy.cluster=default
k8s:io.cilium.k8s.policy.serviceaccount=default
k8s:io.kubernetes.pod.namespace=default
k8s:org=empire
3339 Enabled Disabled 22839 k8s:class=deathstar 10.15.72.39 ready
k8s:io.cilium.k8s.policy.cluster=default
k8s:io.cilium.k8s.policy.serviceaccount=default
k8s:io.kubernetes.pod.namespace=default
k8s:org=empire
3738 Disabled Disabled 47764 k8s:class=xwing 10.15.116.85 ready
k8s:io.cilium.k8s.policy.cluster=default
k8s:io.cilium.k8s.policy.serviceaccount=default
k8s:io.kubernetes.pod.namespace=default
k8s:org=alliance
3837 Disabled Disabled 9164 k8s:class=tiefighter 10.15.22.126 ready
k8s:io.cilium.k8s.policy.cluster=default
k8s:io.cilium.k8s.policy.serviceaccount=default
k8s:io.kubernetes.pod.namespace=default
k8s:org=empire
You can also inspect the policy details via kubectl
$ kubectl get cnp
NAME AGE
rule1 2m
$ kubectl describe cnp rule1
Name: rule1
Namespace: default
Labels: <none>
Annotations: <none>
API Version: cilium.io/v2
Description: L3-L4 policy to restrict deathstar access to empire ships only
Kind: CiliumNetworkPolicy
Metadata:
Creation Timestamp: 2019-01-23T12:36:32Z
Generation: 1
Resource Version: 1115
Self Link: /apis/cilium.io/v2/namespaces/default/ciliumnetworkpolicies/rule1
UID: 837a2f1b-1f0b-11e9-9609-080027702f09
Spec:
Endpoint Selector:
Match Labels:
Class: deathstar
Org: empire
Ingress:
From Endpoints:
Match Labels:
Org: empire
To Ports:
Ports:
Port: 80
Protocol: TCP
Status:
Nodes:
Minikube:
Enforcing: true
Last Updated: 2019-01-23T12:36:32.277839184Z
Local Policy Revision: 5
Ok: true
Events: <none>
Apply and Test HTTP-aware L7 Policy¶
In the simple scenario above, it was sufficient to either give tiefighter / xwing full access to deathstar’s API or no access at all. But to provide the strongest security (i.e., enforce least-privilege isolation) between microservices, each service that calls deathstar’s API should be limited to making only the set of HTTP requests it requires for legitimate operation.
For example, consider that the deathstar service exposes some maintenance APIs which should not be called by random empire ships. To see this run:
$ kubectl exec tiefighter -- curl -s -XPUT deathstar.default.svc.cluster.local/v1/exhaust-port
Panic: deathstar exploded
goroutine 1 [running]:
main.HandleGarbage(0x2080c3f50, 0x2, 0x4, 0x425c0, 0x5, 0xa)
/code/src/github.com/empire/deathstar/
temp/main.go:9 +0x64
main.main()
/code/src/github.com/empire/deathstar/
temp/main.go:5 +0x85
While this is an illustrative example, unauthorized access such as above can have adverse security repercussions.
L7 Policy with Cilium and Kubernetes
Cilium is capable of enforcing HTTP-layer (i.e., L7) policies to limit what URLs the tiefighter is allowed to reach. Here is an example policy file that extends our original policy by limiting tiefighter to making only a POST /v1/request-landing API call, but disallowing all other calls (including PUT /v1/exhaust-port).
apiVersion: "cilium.io/v2"
kind: CiliumNetworkPolicy
description: "L7 policy to restrict access to specific HTTP call"
metadata:
name: "rule1"
spec:
endpointSelector:
matchLabels:
org: empire
class: deathstar
ingress:
- fromEndpoints:
- matchLabels:
org: empire
toPorts:
- ports:
- port: "80"
protocol: TCP
rules:
http:
- method: "POST"
path: "/v1/request-landing"
Update the existing rule to apply L7-aware policy to protect app1 using:
$ kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/minikube/sw_l3_l4_l7_policy.yaml ciliumnetworkpolicy.cilium.io/rule1 configured
We can now re-run the same test as above, but we will see a different outcome:
$ kubectl exec tiefighter -- curl -s -XPOST deathstar.default.svc.cluster.local/v1/request-landing
Ship landed
and
$ kubectl exec tiefighter -- curl -s -XPUT deathstar.default.svc.cluster.local/v1/exhaust-port
Access denied
As you can see, with Cilium L7 security policies, we are able to permit tiefighter to access only the required API resources on deathstar, thereby implementing a “least privilege” security approach for communication between microservices.
You can observe the L7 policy via kubectl:
$ kubectl describe ciliumnetworkpolicies
Name: rule1
Namespace: default
Labels: <none>
Annotations: kubectl.kubernetes.io/last-applied-configuration:
{"apiVersion":"cilium.io/v2","description":"L7 policy to restrict access to specific HTTP call","kind":"CiliumNetworkPolicy","metadata":{"...
API Version: cilium.io/v2
Description: L7 policy to restrict access to specific HTTP call
Kind: CiliumNetworkPolicy
Metadata:
Creation Timestamp: 2019-01-23T12:36:32Z
Generation: 2
Resource Version: 1484
Self Link: /apis/cilium.io/v2/namespaces/default/ciliumnetworkpolicies/rule1
UID: 837a2f1b-1f0b-11e9-9609-080027702f09
Spec:
Endpoint Selector:
Match Labels:
Class: deathstar
Org: empire
Ingress:
From Endpoints:
Match Labels:
Org: empire
To Ports:
Ports:
Port: 80
Protocol: TCP
Rules:
Http:
Method: POST
Path: /v1/request-landing
Status:
Nodes:
Minikube:
Annotations:
Kubectl . Kubernetes . Io / Last - Applied - Configuration: {"apiVersion":"cilium.io/v2","description":"L7 policy to restrict access to specific HTTP call","kind":"CiliumNetworkPolicy","metadata":{"annotations":{},"name":"rule1","namespace":"default"},"spec":{"endpointSelector":{"matchLabels":{"class":"deathstar","org":"empire"}},"ingress":[{"fromEndpoints":[{"matchLabels":{"org":"empire"}}],"toPorts":[{"ports":[{"port":"80","protocol":"TCP"}],"rules":{"http":[{"method":"POST","path":"/v1/request-landing"}]}}]}]}}
Enforcing: true
Last Updated: 2019-01-23T12:39:30.823729308Z
Local Policy Revision: 7
Ok: true
Events: <none>
and cilium CLI:
$ kubectl -n kube-system exec cilium-qh5l2 cilium policy get
[
{
"endpointSelector": {
"matchLabels": {
"any:class": "deathstar",
"any:org": "empire",
"k8s:io.kubernetes.pod.namespace": "default"
}
},
"ingress": [
{
"fromEndpoints": [
{
"matchLabels": {
"any:org": "empire",
"k8s:io.kubernetes.pod.namespace": "default"
}
}
],
"toPorts": [
{
"ports": [
{
"port": "80",
"protocol": "TCP"
}
],
"rules": {
"http": [
{
"path": "/v1/request-landing",
"method": "POST"
}
]
}
}
]
}
],
"labels": [
{
"key": "io.cilium.k8s.policy.name",
"value": "rule1",
"source": "k8s"
},
{
"key": "io.cilium.k8s.policy.uid",
"value": "837a2f1b-1f0b-11e9-9609-080027702f09",
"source": "k8s"
},
{
"key": "io.cilium.k8s.policy.namespace",
"value": "default",
"source": "k8s"
},
{
"key": "io.cilium.k8s.policy.derived-from",
"value": "CiliumNetworkPolicy",
"source": "k8s"
}
]
}
]
Revision: 7
We hope you enjoyed the tutorial. Feel free to play more with the setup, read the rest of the documentation, and reach out to us on the Cilium Slack channel with any questions!
Locking down external access with DNS-based policies¶
This document serves as an introduction for using Cilium to enforce DNS-based security policies for Kubernetes pods.
If you haven’t read the Introduction to Cilium yet, we’d encourage you to do that first.
The best way to get help if you get stuck is to ask a question on the Cilium Slack channel. With Cilium contributors across the globe, there is almost always someone available to help.
Setup Cilium¶
If you have not set up Cilium yet, pick any installation method as described in section Installation to set up Cilium for your Kubernetes environment. If in doubt, pick Getting Started Using Minikube as the simplest way to set up a Kubernetes cluster with Cilium.
Deploy the Demo Application¶
DNS-based policies are very useful for controlling access to services running outside the Kubernetes cluster. DNS acts as a persistent service identifier for both external services provided by AWS, Google, Twilio, Stripe, etc., and internal services such as database clusters running in private subnets outside Kubernetes. CIDR or IP-based policies are cumbersome and hard to maintain as the IPs associated with external services can change frequently. The Cilium DNS-based policies provide an easy mechanism to specify access control while Cilium manages the harder aspects of tracking DNS to IP mapping.
In this guide we will learn about:
- Controlling egress access to services outside the cluster using DNS-based policies
- Using patterns (or wildcards) to whitelist a subset of DNS domains
- Combining DNS, port and L7 rules for restricting access to external service
In line with our Star Wars theme examples, we will use a simple scenario where the empire’s mediabot pods need access to Twitter for managing the empire’s tweets. The pods shouldn’t have access to any other external service.
$ kubectl create -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes-dns/dns-sw-app.yaml $ kubectl get po NAME READY STATUS RESTARTS AGE pod/mediabot 1/1 Running 0 14s
Apply DNS Egress Policy¶
The following Cilium network policy allows mediabot pods to only access api.twitter.com.
apiVersion: "cilium.io/v2"
kind: CiliumNetworkPolicy
metadata:
name: "fqdn"
spec:
endpointSelector:
matchLabels:
org: empire
class: mediabot
egress:
- toFQDNs:
- matchName: "api.twitter.com"
- toEndpoints:
- matchLabels:
"k8s:io.kubernetes.pod.namespace": kube-system
"k8s:k8s-app": kube-dns
toPorts:
- ports:
- port: "53"
protocol: ANY
rules:
dns:
- matchPattern: "*"
Let’s take a closer look at the policy:
- The first egress section uses
toFQDNs: matchNamespecification to allow egress toapi.twitter.com. The destination DNS should match exactly the name specified in the rule. TheendpointSelectorallows only pods with labelsclass: mediabot, org:empireto have the egress access. - The second egress section allows
mediabotpods to accesskube-dnsservice. Note thatrules: dnsinstructs Cilium to inspect and allow DNS lookups matching specified patterns. In this case, inspect and allow all DNS queries.
Note that with this policy the mediabot doesn’t have access to any internal cluster service other than kube-dns. Refer to Network Policy to learn more about policies for controlling access to internal cluster services.
Let’s apply the policy:
$ kubectl create -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes-dns/dns-matchname.yaml
Testing the policy, we see that mediabot has access to api.twitter.com but doesn’t have access to any other external service, e.g., help.twitter.com.
$ kubectl exec -it mediabot -- curl -sL https://api.twitter.com
...
...
$ kubectl exec -it mediabot -- curl -sL https://help.twitter.com
^C
DNS Policies Using Patterns¶
The above policy controlled DNS access based on exact match of the DNS domain name. Often, it is required to allow access to a subset of domains. Let’s say, in the above example, mediabot pods need access to any Twitter sub-domain, e.g., the pattern *.twitter.com. We can achieve this easily by changing the toFQDN rule to use matchPattern instead of matchName.
apiVersion: "cilium.io/v2"
kind: CiliumNetworkPolicy
metadata:
name: "fqdn"
spec:
endpointSelector:
matchLabels:
org: empire
class: mediabot
egress:
- toFQDNs:
- matchPattern: "*.twitter.com"
- toEndpoints:
- matchLabels:
"k8s:io.kubernetes.pod.namespace": kube-system
"k8s:k8s-app": kube-dns
toPorts:
- ports:
- port: "53"
protocol: ANY
rules:
dns:
- matchPattern: "*"
$ kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes-dns/dns-pattern.yaml
Test that mediabot has access to multiple Twitter services for which the DNS matches the pattern *.twitter.com. It is important to note and test that this doesn’t allow access to twitter.com because the *. in the pattern requires one subdomain to be present in the DNS name. You can simply add more matchName and matchPattern clauses to extend the access.
(See DNS based policies to learn more about specifying DNS rules using patterns and names.)
$ kubectl exec -it mediabot -- curl -sL https://help.twitter.com
...
$ kubectl exec -it mediabot -- curl -sL https://about.twitter.com
...
$ kubectl exec -it mediabot -- curl -sL https://twitter.com
^C
Combining DNS, Port and L7 Rules¶
The DNS-based policies can be combined with port (L4) and API (L7) rules to further restrict the access. In our example, we will restrict mediabot pods to access Twitter services only on ports 443. The toPorts section in the policy below achieves the port-based restrictions along with the DNS-based policies.
apiVersion: "cilium.io/v2"
kind: CiliumNetworkPolicy
metadata:
name: "fqdn"
spec:
endpointSelector:
matchLabels:
org: empire
class: mediabot
egress:
- toFQDNs:
- matchPattern: "*.twitter.com"
toPorts:
- ports:
- port: "443"
protocol: TCP
- toEndpoints:
- matchLabels:
"k8s:io.kubernetes.pod.namespace": kube-system
"k8s:k8s-app": kube-dns
toPorts:
- ports:
- port: "53"
protocol: ANY
rules:
dns:
- matchPattern: "*"
$ kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes-dns/dns-port.yaml
Testing, the access to https://help.twitter.com on port 443 will succeed but the access to http://help.twitter.com on port 80 will be denied.
$ kubectl exec -it mediabot -- curl https://help.twitter.com
...
$ kubectl exec -it mediabot -- curl http://help.twitter.com
^C
Refer to Layer 4 Examples and Layer 7 Examples to learn more about Cilium L4 and L7 network policies.
Clean-up¶
$ kubectl delete -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes-dns/dns-sw-app.yaml $ kubectl delete cnp fqdn
Securing a Kafka cluster¶
This document serves as an introduction to using Cilium to enforce Kafka-aware security policies. It is a detailed walk-through of getting a single-node Cilium environment running on your machine. It is designed to take 15-30 minutes.
If you haven’t read the Introduction to Cilium yet, we’d encourage you to do that first.
The best way to get help if you get stuck is to ask a question on the Cilium Slack channel. With Cilium contributors across the globe, there is almost always someone available to help.
Setup Cilium¶
If you have not set up Cilium yet, pick any installation method as described in section Installation to set up Cilium for your Kubernetes environment. If in doubt, pick Getting Started Using Minikube as the simplest way to set up a Kubernetes cluster with Cilium.
Deploy the Demo Application¶
Now that we have Cilium deployed and kube-dns operating correctly we can
deploy our demo Kafka application. Since our first demo of Cilium + HTTP-aware security
policies was Star Wars-themed we decided to do the same for Kafka. While the
HTTP-aware Cilium Star Wars demo
showed how the Galactic Empire used HTTP-aware security policies to protect the Death Star from the
Rebel Alliance, this Kafka demo shows how the lack of Kafka-aware security policies allowed the
Rebels to steal the Death Star plans in the first place.
Kafka is a powerful platform for passing datastreams between different components of an application. A cluster of “Kafka brokers” connect nodes that “produce” data into a data stream, or “consume” data from a datastream. Kafka refers to each datastream as a “topic”. Because scalable and highly-available Kafka clusters are non-trivial to run, the same cluster of Kafka brokers often handles many different topics at once (read this Introduction to Kafka for more background).
In our simple example, the Empire uses a Kafka cluster to handle two different topics:
- empire-announce : Used to broadcast announcements to sites spread across the galaxy
- deathstar-plans : Used by a small group of sites coordinating on building the ultimate battlestation.
To keep the setup small, we will just launch a small number of pods to represent this setup:
- kafka-broker : A single pod running Kafka and Zookeeper representing the Kafka cluster (label app=kafka).
- empire-hq : A pod representing the Empire’s Headquarters, which is the only pod that should produce messages to empire-announce or deathstar-plans (label app=empire-hq).
- empire-backup : A secure backup facility located in Scarif , which is allowed to “consume” from the secret deathstar-plans topic (label app=empire-backup).
- empire-outpost-8888 : A random outpost in the empire. It needs to “consume” messages from the empire-announce topic (label app=empire-outpost).
- empire-outpost-9999 : Another random outpost in the empire that “consumes” messages from the empire-announce topic (label app=empire-outpost).
All pods other than kafka-broker are Kafka clients, which need access to the kafka-broker container on TCP port 9092 in order to send Kafka protocol messages.
The file kafka-sw-app.yaml contains a Kubernetes Deployment for each of the pods described
above, as well as a Kubernetes Service for both Kafka and Zookeeper.
$ kubectl create -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes-kafka/kafka-sw-app.yaml deployment "kafka-broker" created deployment "zookeeper" created service "zook" created service "kafka-service" created deployment "empire-hq" created deployment "empire-outpost-8888" created deployment "empire-outpost-9999" created deployment "empire-backup" created
Kubernetes will deploy the pods and service in the background.
Running kubectl get svc,pods will inform you about the progress of the operation.
Each pod will go through several states until it reaches Running at which
point the setup is ready.
$ kubectl get svc,pods
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kafka-service ClusterIP None <none> 9092/TCP 2m
kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 10m
zook ClusterIP 10.97.250.131 <none> 2181/TCP 2m
NAME READY STATUS RESTARTS AGE
empire-backup-6f4567d5fd-gcrvg 1/1 Running 0 2m
empire-hq-59475b4b64-mrdww 1/1 Running 0 2m
empire-outpost-8888-78dffd49fb-tnnhf 1/1 Running 0 2m
empire-outpost-9999-7dd9fc5f5b-xp6jw 1/1 Running 0 2m
kafka-broker-b874c78fd-jdwqf 1/1 Running 0 2m
zookeeper-85f64b8cd4-nprck 1/1 Running 0 2m
Setup Client Terminals¶
First we will open a set of windows to represent the different Kafka clients discussed above. For consistency, we recommend opening them in the pattern shown in the image below, but this is optional.
In each window, use copy-paste to have each terminal provide a shell inside each pod.
empire-hq terminal:
$ HQ_POD=$(kubectl get pods -l app=empire-hq -o jsonpath='{.items[0].metadata.name}') && kubectl exec -it $HQ_POD -- sh -c "PS1=\"empire-hq $\" /bin/bash"
empire-backup terminal:
$ BACKUP_POD=$(kubectl get pods -l app=empire-backup -o jsonpath='{.items[0].metadata.name}') && kubectl exec -it $BACKUP_POD -- sh -c "PS1=\"empire-backup $\" /bin/bash"
outpost-8888 terminal:
$ OUTPOST_8888_POD=$(kubectl get pods -l outpostid=8888 -o jsonpath='{.items[0].metadata.name}') && kubectl exec -it $OUTPOST_8888_POD -- sh -c "PS1=\"outpost-8888 $\" /bin/bash"
outpost-9999 terminal:
$ OUTPOST_9999_POD=$(kubectl get pods -l outpostid=9999 -o jsonpath='{.items[0].metadata.name}') && kubectl exec -it $OUTPOST_9999_POD -- sh -c "PS1=\"outpost-9999 $\" /bin/bash"
Test Basic Kafka Produce & Consume¶
First, let’s start the consumer clients listening to their respective Kafka topics. All of the consumer commands below will hang intentionally, waiting to print data they consume from the Kafka topic:
In the empire-backup window, start listening on the top-secret deathstar-plans topic:
$ ./kafka-consume.sh --topic deathstar-plans
In the outpost-8888 window, start listening to empire-announcement:
$ ./kafka-consume.sh --topic empire-announce
Do the same in the outpost-9999 window:
$ ./kafka-consume.sh --topic empire-announce
Now from the empire-hq, first produce a message to the empire-announce topic:
$ echo "Happy 40th Birthday to General Tagge" | ./kafka-produce.sh --topic empire-announce
This message will be posted to the empire-announce topic, and shows up in both the outpost-8888 and outpost-9999 windows who consume that topic. It will not show up in empire-backup.
empire-hq can also post a version of the top-secret deathstar plans to the deathstar-plans topic:
$ echo "deathstar reactor design v3" | ./kafka-produce.sh --topic deathstar-plans
This message shows up in the empire-backup window, but not for the outposts.
Congratulations, Kafka is working as expected :)
The Danger of a Compromised Kafka Client¶
But what if a rebel spy gains access to any of the remote outposts that act as Kafka clients? Since every client has access to the Kafka broker on port 9092, it can do some bad stuff. For starters, the outpost container can actually switch roles from a consumer to a producer, sending “malicious” data to all other consumers on the topic.
To prove this, kill the existing kafka-consume.sh command in the outpost-9999 window
by typing control-C and instead run:
$ echo "Vader Booed at Empire Karaoke Party" | ./kafka-produce.sh --topic empire-announce
Uh oh! Outpost-8888 and all of the other outposts in the empire have now received this fake announcement.
But even more nasty from a security perspective is that the outpost container can access any topic on the kafka-broker.
In the outpost-9999 container, run:
$ ./kafka-consume.sh --topic deathstar-plans
"deathstar reactor design v3"
We see that any outpost can actually access the secret deathstar plans. Now we know how the rebels got access to them!
Securing Access to Kafka with Cilium¶
Obviously, it would be much more secure to limit each pod’s access to the Kafka broker to be least privilege (i.e., only what is needed for the app to operate correctly and nothing more).
We can do that with the following Cilium security policy. As with Cilium HTTP policies, we can write policies that identify pods by labels, and then limit the traffic in/out of this pod. In this case, we’ll create a policy that identifies the exact traffic that should be allowed to reach the Kafka broker, and deny the rest.
As an example, a policy could limit containers with label app=empire-outpost to only be able to consume topic empire-announce, but would block any attempt by a compromised container (e.g., empire-outpost-9999) from producing to empire-announce or consuming from deathstar-plans.
Here is the CiliumNetworkPolicy rule that limits access of pods with label app=empire-outpost to only consume on topic empire-announce:
apiVersion: "cilium.io/v2"
kind: CiliumNetworkPolicy
description: "enable outposts to consume empire-announce"
metadata:
name: "rule2"
spec:
endpointSelector:
matchLabels:
app: kafka
ingress:
- fromEndpoints:
- matchLabels:
app: empire-outpost
toPorts:
- ports:
- port: "9092"
protocol: TCP
rules:
kafka:
- role: "consume"
topic: "empire-announce"
A CiliumNetworkPolicy contains a list of rules that define allowed requests, meaning that requests that do not match any rules are denied as invalid.
The above rule applies to inbound (i.e., “ingress”) connections to kafka-broker pods (as indicated by “app: kafka” in the “endpointSelector” section). The rule will apply to connections from pods with label “app: empire-outpost” as indicated by the “fromEndpoints” section. The rule explicitly matches Kafka connections destined to TCP 9092, and allows consume/produce actions on various topics of interest. For example we are allowing consume from topic empire-announce in this case.
The full policy adds two additional rules that permit the legitimate “produce” (topic empire-announce and topic deathstar-plans) from empire-hq and the legitimate consume (topic = “deathstar-plans”) from empire-backup. The full policy can be reviewed by opening the URL in the command below in a browser.
Apply this Kafka-aware network security policy using kubectl in the main window:
$ kubectl create -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes-kafka/kafka-sw-security-policy.yaml
If we then again try to produce a message from outpost-9999 to empire-annnounce, it is denied. Type control-c and then run:
$ echo "Vader Trips on His Own Cape" | ./kafka-produce.sh --topic empire-announce
>>[2018-04-10 23:50:34,638] ERROR Error when sending message to topic empire-announce with key: null, value: 27 bytes with error: (org.apache.kafka.clients.producer.internals.ErrorLoggingCallback)
org.apache.kafka.common.errors.TopicAuthorizationException: Not authorized to access topics: [empire-announce]
This is because the policy does not allow messages with role = “produce” for topic “empire-announce” from containers with label app = empire-outpost. Its worth noting that we don’t simply drop the message (which could easily be confused with a network error), but rather we respond with the Kafka access denied error (similar to how HTTP would return an error code of 403 unauthorized).
Likewise, if the outpost container ever tries to consume from topic deathstar-plans, it is denied, as role = consume is only allowed for topic empire-announce.
To test, from the outpost-9999 terminal, run:
$./kafka-consume.sh --topic deathstar-plans
[2018-04-10 23:51:12,956] WARN Error while fetching metadata with correlation id 2 : {deathstar-plans=TOPIC_AUTHORIZATION_FAILED} (org.apache.kafka.clients.NetworkClient)
This is blocked as well, thanks to the Cilium network policy. Imagine how different things would have been if the empire had been using Cilium from the beginning!
Clean Up¶
You have now installed Cilium, deployed a demo app, and tested both L7 Kafka-aware network security policies. To clean up, run:
$ minikube delete
After this, you can re-run the tutorial from Step 1.
How to secure gRPC¶
This document serves as an introduction to using Cilium to enforce gRPC-aware security policies. It is a detailed walk-through of getting a single-node Cilium environment running on your machine. It is designed to take 15-30 minutes.
If you haven’t read the Introduction to Cilium yet, we’d encourage you to do that first.
The best way to get help if you get stuck is to ask a question on the Cilium Slack channel. With Cilium contributors across the globe, there is almost always someone available to help.
Setup Cilium¶
If you have not set up Cilium yet, pick any installation method as described in section Installation to set up Cilium for your Kubernetes environment. If in doubt, pick Getting Started Using Minikube as the simplest way to set up a Kubernetes cluster with Cilium.
It is important for this demo that kube-dns is working correctly. To know the
status of kube-dns you can run the following command:
$ kubectl get deployment kube-dns -n kube-system
NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE
kube-dns 1 1 1 1 13h
Where at least one pod should be available.
Deploy the Demo Application¶
Now that we have Cilium deployed and kube-dns operating correctly we can
deploy our demo gRPC application. Since our first demo of Cilium + HTTP-aware security
policies was Star Wars-themed, we decided to do the same for gRPC. While the
HTTP-aware Cilium Star Wars demo
showed how the Galactic Empire used HTTP-aware security policies to protect the Death Star from the
Rebel Alliance, this gRPC demo shows how the lack of gRPC-aware security policies allowed Leia, Chewbacca, Lando, C-3PO, and R2-D2 to escape from Cloud City, which had been overtaken by
empire forces.
gRPC is a high-performance RPC framework built on top of the protobuf serialization/deserialization library popularized by Google. There are gRPC bindings for many programming languages, and the efficiency of the protobuf parsing as well as advantages from leveraging HTTP 2 as a transport make it a popular RPC framework for those building new microservices from scratch.
For those unfamiliar with the details of the movie, Leia and the other rebels are fleeing storm troopers and trying to reach the space port platform where the Millennium Falcon is parked, so they can fly out of Cloud City. However, the door to the platform is closed, and the access code has been changed. However, R2-D2 is able to access the Cloud City computer system via a public terminal, and disable this security, opening the door and letting the Rebels reach the Millennium Falcon just in time to escape.
In our example, Cloud City’s internal computer system is built as a set of gRPC-based microservices (who knew that gRPC was actually invented a long time ago, in a galaxy far, far away?).
With gRPC, each service is defined using a language independent protocol buffer definition. Here is the definition for the system used to manage doors within Cloud City:
package cloudcity;
// The door manager service definition.
service DoorManager {
// Get human readable name of door.
rpc GetName(DoorRequest) returns (DoorNameReply) {}
// Find the location of this door.
rpc GetLocation (DoorRequest) returns (DoorLocationReply) {}
// Find out whether door is open or closed
rpc GetStatus(DoorRequest) returns (DoorStatusReply) {}
// Request maintenance on the door
rpc RequestMaintenance(DoorMaintRequest) returns (DoorActionReply) {}
// Set Access Code to Open / Lock the door
rpc SetAccessCode(DoorAccessCodeRequest) returns (DoorActionReply) {}
}
To keep the setup small, we will just launch two pods to represent this setup:
- cc-door-mgr: A single pod running the gRPC door manager service with label
app=cc-door-mgr. - terminal-87: One of the public network access terminals scattered across Cloud City. R2-D2 plugs into terminal-87 as the rebels are desperately trying to escape. This terminal uses the gRPC client code to communicate with the door management services with label
app=public-terminal.
The file cc-door-app.yaml contains a Kubernetes Deployment for the door manager
service, a Kubernetes Pod representing terminal-87, and a Kubernetes Service for
the door manager services. To deploy this example app, run:
$ kubectl create -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes-grpc/cc-door-app.yaml deployment "cc-door-mgr" created service "cc-door-server" created pod "terminal-87" created
Kubernetes will deploy the pods and service in the background. Running
kubectl get svc,pods will inform you about the progress of the operation.
Each pod will go through several states until it reaches Running at which
point the setup is ready.
$ kubectl get pods,svc
NAME READY STATUS RESTARTS AGE
po/cc-door-mgr-3590146619-cv4jn 1/1 Running 0 1m
po/terminal-87 1/1 Running 0 1m
NAME CLUSTER-IP EXTERNAL-IP PORT(S) AGE
svc/cc-door-server 10.0.0.72 <none> 50051/TCP 1m
svc/kubernetes 10.0.0.1 <none> 443/TCP 6m
Test Access Between gRPC Client and Server¶
First, let’s confirm that the public terminal can properly act as a client to the door service. We can test this by running a Python gRPC client for the door service that exists in the terminal-87 container.
We’ll invoke the ‘cc_door_client’ with the name of the gRPC method to call, and any parameters (in this case, the door-id):
$ kubectl exec terminal-87 -- python3 /cloudcity/cc_door_client.py GetName 1
Door name is: Spaceport Door #1
$ kubectl exec terminal-87 -- python3 /cloudcity/cc_door_client.py GetLocation 1
Door location is lat = 10.222200393676758 long = 68.87879943847656
Exposing this information to public terminals seems quite useful, as it helps travelers new
to Cloud City identify and locate different doors. But recall that the door service also
exposes several other methods, including SetAccessCode. If access to the door manager
service is protected only using traditional IP and port-based firewalling, the TCP port of
the service (50051 in this example) will be wide open to allow legitimate calls like
GetName and GetLocation, which also leave more sensitive calls like SetAccessCode exposed as
well. It is this mismatch between the course granularity of traditional firewalls and
the fine-grained nature of gRPC calls that R2-D2 exploited to override the security
and help the rebels escape.
To see this, run:
$ kubectl exec terminal-87 -- python3 /cloudcity/cc_door_client.py SetAccessCode 1 999
Successfully set AccessCode to 999
Securing Access to a gRPC Service with Cilium¶
Once the legitimate owners of Cloud City recover the city from the empire, how can they
use Cilium to plug this key security hole and block requests to SetAccessCode and GetStatus
while still allowing GetName, GetLocation, and RequestMaintenance?
Since gRPC build on top of HTTP, this can be achieved easily by understanding how a gRPC call is mapped to an HTTP URL, and then applying a Cilium HTTP-aware filter to allow public terminals to only invoke a subset of all the total gRPC methods available on the door service.
Each gRPC method is mapped to an HTTP POST call to a URL of the form
/cloudcity.DoorManager/<method-name>.
As a result, the following CiliumNetworkPolicy rule limits access of pods with label
app=public-terminal to only invoke GetName, GetLocation, and RequestMaintenance
on the door service, identified by label app=cc-door-sgr:
apiVersion: "cilium.io/v2"
kind: CiliumNetworkPolicy
description: "L7 policy to allow public terminals to call GetName, GetLocation, and RequestMaintenance, but not GetState, or SetAccessCode on the Door Manager Service"
metadata:
name: "rule1"
spec:
endpointSelector:
matchLabels:
app: cc-door-mgr
ingress:
- fromEndpoints:
- matchLabels:
app: public-terminal
toPorts:
- ports:
- port: "50051"
protocol: TCP
rules:
http:
- method: "POST"
path: "/cloudcity.DoorManager/GetName"
- method: "POST"
path: "/cloudcity.DoorManager/GetLocation"
- method: "POST"
path: "/cloudcity.DoorManager/RequestMaintenance"
A CiliumNetworkPolicy contains a list of rules that define allowed requests,
meaning that requests that do not match any rules (e.g., SetAccessCode) are denied as invalid.
The above rule applies to inbound (i.e., “ingress”) connections to cc-door-mgr pods (as
indicated by app: cc-door-mgr
in the “endpointSelector” section). The rule will apply to connections from pods with label
app: public-terminal as indicated by the “fromEndpoints” section.
The rule explicitly matches
gRPC connections destined to TCP 50051, and white-lists specifically the permitted URLs.
Apply this gRPC-aware network security policy using kubectl in the main window:
$ kubectl create -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes-grpc/cc-door-ingress-security.yaml
After this security policy is in place, access to the innocuous calls like GetLocation
still works as intended:
$ kubectl exec terminal-87 -- python3 /cloudcity/cc_door_client.py GetLocation 1
Door location is lat = 10.222200393676758 long = 68.87879943847656
However, if we then again try to invoke SetAccessCode, it is denied:
$ kubectl exec terminal-87 -- python3 /cloudcity/cc_door_client.py SetAccessCode 1 999
Traceback (most recent call last):
File "/cloudcity/cc_door_client.py", line 71, in <module>
run()
File "/cloudcity/cc_door_client.py", line 53, in run
door_id=int(arg2), access_code=int(arg3)))
File "/usr/local/lib/python3.4/dist-packages/grpc/_channel.py", line 492, in __call__
return _end_unary_response_blocking(state, call, False, deadline)
File "/usr/local/lib/python3.4/dist-packages/grpc/_channel.py", line 440, in _end_unary_response_blocking
raise _Rendezvous(state, None, None, deadline)
grpc._channel._Rendezvous: <_Rendezvous of RPC that terminated with (StatusCode.CANCELLED, Received http2 header with status: 403)>
This is now blocked, thanks to the Cilium network policy. And notice that unlike a traditional firewall which would just drop packets in a way indistinguishable from a network failure, because Cilium operates at the API-layer, it can explicitly reply with an custom HTTP 403 Unauthorized error, indicating that the request was intentionally denied for security reasons.
Thank goodness that the empire IT staff hadn’t had time to deploy Cilium on Cloud City’s internal network prior to the escape attempt, or things might have turned out quite differently for Leia and the other Rebels!
Clean-Up¶
You have now installed Cilium, deployed a demo app, and tested L7 gRPC-aware network security policies. To clean-up, run:
$ minikube delete
After this, you can re-run the tutorial from Step 1.
Getting Started Securing Elasticsearch¶
This document serves as an introduction for using Cilium to enforce Elasticsearch-aware security policies. It is a detailed walk-through of getting a single-node Cilium environment running on your machine. It is designed to take 15-30 minutes.
If you haven’t read the Introduction to Cilium yet, we’d encourage you to do that first.
The best way to get help if you get stuck is to ask a question on the Cilium Slack channel. With Cilium contributors across the globe, there is almost always someone available to help.
Setup Cilium¶
If you have not set up Cilium yet, pick any installation method as described in section Installation to set up Cilium for your Kubernetes environment. If in doubt, pick Getting Started Using Minikube as the simplest way to set up a Kubernetes cluster with Cilium.
Deploy the Demo Application¶
Following the Cilium tradition, we will use a Star Wars-inspired example. The Empire has a large scale Elasticsearch cluster which is used for storing a variety of data including:
index: troop_logs: Stormtroopers performance logs collected from every outpost which are used to identify and eliminate weak performers!index: spaceship_diagnostics: Spaceships diagnostics data collected from every spaceship which is used for R&D and improvement of the spaceships.
Every outpost has an Elasticsearch client service to upload the Stormtroopers logs. And every spaceship has a service to upload diagnostics. Similarly, the Empire headquarters has a service to search and analyze the troop logs and spaceship diagnostics data. Before we look into the security concerns, let’s first create this application scenario in minikube.
Deploy the app using command below, which will create
- An
elasticsearchservice with the selector labelcomponent:elasticsearchand a pod running Elasticsearch. - Three Elasticsearch clients one each for
empire-hq,outpostandspaceship.
$ kubectl create -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes-es/es-sw-app.yaml serviceaccount "elasticsearch" created service "elasticsearch" created replicationcontroller "es" created role "elasticsearch" created rolebinding "elasticsearch" created pod "outpost" created pod "empire-hq" created pod "spaceship" created
$ kubectl get svc,pods
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
svc/elasticsearch NodePort 10.111.238.254 <none> 9200:30130/TCP,9300:31721/TCP 2d
svc/etcd-cilium NodePort 10.98.67.60 <none> 32379:31079/TCP,32380:31080/TCP 9d
svc/kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 9d
NAME READY STATUS RESTARTS AGE
po/empire-hq 1/1 Running 0 2d
po/es-g9qk2 1/1 Running 0 2d
po/etcd-cilium-0 1/1 Running 0 9d
po/outpost 1/1 Running 0 2d
po/spaceship 1/1 Running 0 2d
Security Risks for Elasticsearch Access¶
For Elasticsearch clusters the least privilege security challenge is to give clients access only to particular indices, and to limit the operations each client is allowed to perform on each index. In this example, the outpost Elasticsearch clients only need access to upload troop logs; and the empire-hq client only needs search access to both the indices. From the security perspective, the outposts are weak spots and susceptible to be captured by the rebels. Once compromised, the clients can be used to search and manipulate the critical data in Elasticsearch. We can simulate this attack, but first let’s run the commands for legitimate behavior for all the client services.
outpost client uploading troop logs
$ kubectl exec outpost -- python upload_logs.py
Uploading Stormtroopers Performance Logs
created : {'_index': 'troop_logs', '_type': 'log', '_id': '1', '_version': 1, 'result': 'created', '_shards': {'total': 2, 'successful': 1, 'failed': 0}, 'created': True}
spaceship uploading diagnostics
$ kubectl exec spaceship -- python upload_diagnostics.py
Uploading Spaceship Diagnostics
created : {'_index': 'spaceship_diagnostics', '_type': 'stats', '_id': '1', '_version': 1, 'result': 'created', '_shards': {'total': 2, 'successful': 1, 'failed': 0}, 'created': True}
empire-hq running search queries for logs and diagnostics
$ kubectl exec empire-hq -- python search.py
Searching for Spaceship Diagnostics
Got 1 Hits:
{'_index': 'spaceship_diagnostics', '_type': 'stats', '_id': '1', '_score': 1.0, \
'_source': {'spaceshipid': '3459B78XNZTF', 'type': 'tiefighter', 'title': 'Engine Diagnostics', \
'stats': '[CRITICAL] [ENGINE BURN @SPEED 5000 km/s] [CHANCE 80%]'}}
Searching for Stormtroopers Performance Logs
Got 1 Hits:
{'_index': 'troop_logs', '_type': 'log', '_id': '1', '_score': 1.0, \
'_source': {'outpost': 'Endor', 'datetime': '33 ABY 4AM DST', 'title': 'Endor Corps 1: Morning Drill', \
'notes': '5100 PRESENT; 15 ABSENT; 130 CODE-RED BELOW PAR PERFORMANCE'}}
Now imagine an outpost captured by the rebels. In the commands below, the rebels first search all the indices and then manipulate the diagnostics data from a compromised outpost.
$ kubectl exec outpost -- python search.py
Searching for Spaceship Diagnostics
Got 1 Hits:
{'_index': 'spaceship_diagnostics', '_type': 'stats', '_id': '1', '_score': 1.0, \
'_source': {'spaceshipid': '3459B78XNZTF', 'type': 'tiefighter', 'title': 'Engine Diagnostics', \
'stats': '[CRITICAL] [ENGINE BURN @SPEED 5000 km/s] [CHANCE 80%]'}}
Searching for Stormtroopers Performance Logs
Got 1 Hits:
{'_index': 'troop_logs', '_type': 'log', '_id': '1', '_score': 1.0, \
'_source': {'outpost': 'Endor', 'datetime': '33 ABY 4AM DST', 'title': 'Endor Corps 1: Morning Drill', \
'notes': '5100 PRESENT; 15 ABSENT; 130 CODE-RED BELOW PAR PERFORMANCE'}}
Rebels manipulate spaceship diagnostics data so that the spaceship defects are not known to the empire-hq! (Hint: Rebels have changed the stats for the tiefighter spaceship, a change hard to detect but with adverse impact!)
$ kubectl exec outpost -- python update.py
Uploading Spaceship Diagnostics
{'_index': 'spaceship_diagnostics', '_type': 'stats', '_id': '1', '_score': 1.0, \
'_source': {'spaceshipid': '3459B78XNZTF', 'type': 'tiefighter', 'title': 'Engine Diagnostics', \
'stats': '[OK] [ENGINE OK @SPEED 5000 km/s]'}}
Securing Elasticsearch Using Cilium¶
Following the least privilege security principle, we want to the allow the following legitimate actions and nothing more:
outpostservice only has upload access toindex: troop_logsspaceshipservice only has upload access toindex: spaceship_diagnosticsempire-hqservice only has search access for both the indices
Fortunately, the Empire DevOps team is using Cilium for their Kubernetes cluster. Cilium provides L7 visibility and security policies to control Elasticsearch API access. Cilium follows the white-list, least privilege model for security. That is to say, a CiliumNetworkPolicy contains a list of rules that define allowed requests and any request that does not match the rules is denied.
In this example, the policy rules are defined for inbound traffic (i.e., “ingress”) connections to the elasticsearch service. Note that endpoints selected as backend pods for the service are defined by the selector labels. Selector labels use the same concept as Kubernetes to define a service. In this example, label component: elasticsearch defines the pods that are part of the elasticsearch service in Kubernetes.
In the policy file below, you will see the following rules for controlling the indices access and actions performed:
fromEndpointswith labelsapp:spaceshiponlyHTTPPUTis allowed on paths matching regex^/spaceship_diagnostics/stats/.*$fromEndpointswith labelsapp:outpostonlyHTTPPUTis allowed on paths matching regex^/troop_logs/log/.*$fromEndpointswith labelsapp:empireonlyHTTPGETis allowed on paths matching regex^/spaceship_diagnostics/_search/??.*$and^/troop_logs/search/??.*$
apiVersion: cilium.io/v2
kind: CiliumNetworkPolicy
metadata:
name: secure-empire-elasticsearch
namespace: default
specs:
- endpointSelector:
matchLabels:
component: elasticsearch
ingress:
- fromEndpoints:
- matchLabels:
app: spaceship
toPorts:
- ports:
- port: "9200"
protocol: TCP
rules:
http:
- method: ^PUT$
path: ^/spaceship_diagnostics/stats/.*$
- fromEndpoints:
- matchLabels:
app: empire-hq
toPorts:
- ports:
- port: "9200"
protocol: TCP
rules:
http:
- method: ^GET$
path: ^/spaceship_diagnostics/_search/??.*$
- method: ^GET$
path: ^/troop_logs/_search/??.*$
- fromEndpoints:
- matchLabels:
app: outpost
toPorts:
- ports:
- port: "9200"
protocol: TCP
rules:
http:
- method: ^PUT$
path: ^/troop_logs/log/.*$
- egress:
- toEndpoints:
- matchExpressions:
- key: k8s:io.kubernetes.pod.namespace
operator: Exists
- toEntities:
- cluster
- host
endpointSelector: {}
ingress:
- {}
Apply this Elasticsearch-aware network security policy using kubectl:
$ kubectl create -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes-es/es-sw-policy.yaml ciliumnetworkpolicy "secure-empire-elasticsearch" created
Let’s test the security policies. Firstly, the search access is blocked for both outpost and spaceship. So from a compromised outpost, rebels will not be able to search and obtain knowledge about troops and spaceship diagnostics. Secondly, the outpost clients don’t have access to create or update the index: spaceship_diagnostics.
$ kubectl exec outpost -- python search.py
GET http://elasticsearch:9200/spaceship_diagnostics/_search [status:403 request:0.008s]
...
...
elasticsearch.exceptions.AuthorizationException: TransportError(403, 'Access denied\r\n')
command terminated with exit code 1
$ kubectl exec outpost -- python update.py
PUT http://elasticsearch:9200/spaceship_diagnostics/stats/1 [status:403 request:0.006s]
...
...
elasticsearch.exceptions.AuthorizationException: TransportError(403, 'Access denied\r\n')
command terminated with exit code 1
We can re-run any of the below commands to show that the security policy still allows all legitimate requests (i.e., no 403 errors are returned).
$ kubectl exec outpost -- python upload_logs.py
...
$ kubectl exec spaceship -- python upload_diagnostics.py
...
$ kubectl exec empire-hq -- python search.py
...
Clean Up¶
You have now installed Cilium, deployed a demo app, and finally deployed & tested Elasticsearch-aware network security policies. To clean up, run:
$ minikube delete
How to Secure a Cassandra Database¶
This document serves as an introduction to using Cilium to enforce Cassandra-aware security policies. It is a detailed walk-through of getting a single-node Cilium environment running on your machine. It is designed to take 15-30 minutes.
NOTE: Cassandra-aware policy support is still in beta phase. It is not yet ready for production use. Additionally, the Cassandra-specific policy language is highly likely to change in a future Cilium version.
If you haven’t read the Introduction to Cilium yet, we’d encourage you to do that first.
The best way to get help if you get stuck is to ask a question on the Cilium Slack channel. With Cilium contributors across the globe, there is almost always someone available to help.
Setup Cilium¶
If you have not set up Cilium yet, pick any installation method as described in section Installation to set up Cilium for your Kubernetes environment. If in doubt, pick Getting Started Using Minikube as the simplest way to set up a Kubernetes cluster with Cilium.
Deploy the Demo Application¶
Now that we have Cilium deployed and kube-dns operating correctly we can
deploy our demo Cassandra application. Since our first
HTTP-aware Cilium Star Wars demo
showed how the Galactic Empire used HTTP-aware security policies to protect the Death Star from the
Rebel Alliance, this Cassandra demo is Star Wars-themed as well.
Apache Cassanadra is a popular NOSQL database focused on delivering high-performance transactions (especially on writes) without sacrificing on availability or scale. Cassandra operates as a cluster of servers, and Cassandra clients query these services via a the native Cassandra protocol . Cilium understands the Cassandra protocol, and thus is able to provide deep visibility and control over which clients are able to access particular tables inside a Cassandra cluster, and which actions (e.g., “select”, “insert”, “update”, “delete”) can be performed on tables.
With Cassandra, each table belongs to a “keyspace”, allowing multiple groups to use a single cluster without conflicting. Cassandra queries specify the full table name qualified by the keyspace using the syntax “<keyspace>.<table>”.
In our simple example, the Empire uses a Cassandra cluster to store two different types of information:
- Employee Attendance Records : Use to store daily attendance data (attendance.daily_records).
- Deathstar Scrum Reports : Daily scrum reports from the teams working on the Deathstar (deathstar.scrum_reports).
To keep the setup small, we will just launch a small number of pods to represent this setup:
- cass-server : A single pod running the Cassandra service, representing a Cassandra cluster (label app=cass-server).
- empire-hq : A pod representing the Empire’s Headquarters, which is the only pod that should be able to read all attendance data, or read/write the Deathstar scrum notes (label app=empire-hq).
- empire-outpost : A random outpost in the empire. It should be able to insert employee attendance records, but not read records for other empire facilities. It also should not have any access to the deathstar keyspace (label app=empire-outpost).
All pods other than cass-server are Cassandra clients, which need access to the cass-server container on TCP port 9042 in order to send Cassandra protocol messages.
The file cass-sw-app.yaml contains a Kubernetes Deployment for each of the pods described
above, as well as a Kubernetes Service cassandra-svc for the Cassandra cluster.
$ kubectl create -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes-cassandra/cass-sw-app.yaml deployment.extensions/cass-server created service/cassandra-svc created deployment.extensions/empire-hq created deployment.extensions/empire-outpost created
Kubernetes will deploy the pods and service in the background.
Running kubectl get svc,pods will inform you about the progress of the operation.
Each pod will go through several states until it reaches Running at which
point the setup is ready.
$ kubectl get svc,pods
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/cassandra-svc ClusterIP None <none> 9042/TCP 1m
service/kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 15h
NAME READY STATUS RESTARTS AGE
pod/cass-server-5674d5b946-x8v4j 1/1 Running 0 1m
pod/empire-hq-c494c664d-xmvdl 1/1 Running 0 1m
pod/empire-outpost-68bf76858d-flczn 1/1 Running 0 1m
Step 3: Test Basic Cassandra Access¶
First, we’ll create the keyspaces and tables mentioned above, and populate them with some initial data:
$ curl -s https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes-cassandra/cass-populate-tables.sh | bash
Next, create two environment variables that refer to the empire-hq and empire-outpost pods:
$ HQ_POD=$(kubectl get pods -l app=empire-hq -o jsonpath='{.items[0].metadata.name}')
$ OUTPOST_POD=$(kubectl get pods -l app=empire-outpost -o jsonpath='{.items[0].metadata.name}')
Now we will run the ‘cqlsh’ Cassandra client in the empire-outpost pod, telling it to access the Cassandra cluster identified by the ‘cassandra-svc’ DNS name:
$ kubectl exec -it $OUTPOST_POD cqlsh -- cassandra-svc
Connected to Test Cluster at cassandra-svc:9042.
[cqlsh 5.0.1 | Cassandra 3.11.3 | CQL spec 3.4.4 | Native protocol v4]
Use HELP for help.
cqlsh>
Next, using the cqlsh prompt, we’ll show that the outpost can add records to the “daily_records” table in the “attendance” keyspace:
cqlsh> INSERT INTO attendance.daily_records (creation, loc_id, present, empire_member_id) values (now(), 074AD3B9-A47D-4EBC-83D3-CAD75B1911CE, true, 6AD3139F-EBFC-4E0C-9F79-8F997BA01D90);
We have confirmed that outposts are able to report daily attendance records as intended. We’re off to a good start!
The Danger of a Compromised Cassandra Client¶
But what if a rebel spy gains access to any of the remote outposts that act as a Cassandra client? Since every client has access to the Cassandra API on port 9042, it can do some bad stuff. For starters, the outpost container can not only add entries to the attendance.daily_reports table, but it could read all entries as well.
To see this, we can run the following command:
$ cqlsh> SELECT * FROM attendance.daily_records;
loc_id | creation | empire_member_id | present
--------------------------------------+--------------------------------------+--------------------------------------+---------
a855e745-69d8-4159-b8b6-e2bafed8387a | c692ce90-bf57-11e8-98e6-f1a9f45fc4d8 | cee6d956-dbeb-4b09-ad21-1dd93290fa6c | True
5b9a7990-657e-442d-a3f7-94484f06696e | c8493120-bf57-11e8-98e6-f1a9f45fc4d8 | e74a0300-94f3-4b3d-aee4-fea85eca5af7 | True
53ed94d0-ddac-4b14-8c2f-ba6f83a8218c | c641a150-bf57-11e8-98e6-f1a9f45fc4d8 | 104ddbb6-f2f7-4cd0-8683-cc18cccc1326 | True
074ad3b9-a47d-4ebc-83d3-cad75b1911ce | 9674ed40-bf59-11e8-98e6-f1a9f45fc4d8 | 6ad3139f-ebfc-4e0c-9f79-8f997ba01d90 | True
fe72cc39-dffb-45dc-8e5f-86c674a58951 | c5e79a70-bf57-11e8-98e6-f1a9f45fc4d8 | 6782689c-0488-4ecb-b582-a2ccd282405e | True
461f4176-eb4c-4bcc-a08a-46787ca01af3 | c6fefde0-bf57-11e8-98e6-f1a9f45fc4d8 | 01009199-3d6b-4041-9c43-b1ca9aef021c | True
64dbf608-6947-4a23-98e9-63339c413136 | c8096900-bf57-11e8-98e6-f1a9f45fc4d8 | 6ffe024e-beff-4370-a1b5-dcf6330ec82b | True
13cefcac-5652-4c69-a3c2-1484671f2467 | c53f4c80-bf57-11e8-98e6-f1a9f45fc4d8 | 55218adc-2f3d-4f84-a693-87a2c238bb26 | True
eabf5185-376b-4d4a-a5b5-99f912d98279 | c593fc30-bf57-11e8-98e6-f1a9f45fc4d8 | 5e22159b-f3a9-4f8a-9944-97375df570e9 | True
3c0ae2d1-c836-4aa4-8fe2-5db6cc1f92fc | c7af1400-bf57-11e8-98e6-f1a9f45fc4d8 | 0ccb3df7-78d0-4434-8a7f-4bfa8d714275 | True
31a292e0-2e28-4a7d-8c84-8d4cf0c57483 | c4e0d8d0-bf57-11e8-98e6-f1a9f45fc4d8 | 8fe7625c-f482-4eb6-b33e-271440777403 | True
(11 rows)
Uh oh! The rebels now has strategic information about empire troop strengths at each location in the galaxy.
But even more nasty from a security perspective is that the outpost container can also access information in any keyspace, including the deathstar keyspace. For example, run:
$ cqlsh> SELECT * FROM deathstar.scrum_notes;
empire_member_id | content | creation
--------------------------------------+----------------------------------------------------------------------------------------------------------------+--------------------------------------
34e564c2-781b-477e-acd0-b357d67f94f2 | Designed protective shield for deathstar. Could be based on nearby moon. Feature punted to v2. Not blocked. | c3c8b210-bf57-11e8-98e6-f1a9f45fc4d8
dfa974ea-88cd-4e9b-85e3-542b9d00e2df | I think the exhaust port could be vulnerable to a direct hit. Hope no one finds out about it. Not blocked. | c37f4d00-bf57-11e8-98e6-f1a9f45fc4d8
ee12306a-7b44-46a4-ad68-42e86f0f111e | Trying to figure out if we should paint it medium grey, light grey, or medium-light grey. Not blocked. | c32daa90-bf57-11e8-98e6-f1a9f45fc4d8
(3 rows)
We see that any outpost can actually access the deathstar scrum notes, which mentions a pretty serious issue with the exhaust port.
Securing Access to Cassandra with Cilium¶
Obviously, it would be much more secure to limit each pod’s access to the Cassandra server to be least privilege (i.e., only what is needed for the app to operate correctly and nothing more).
We can do that with the following Cilium security policy. As with Cilium HTTP policies, we can write policies that identify pods by labels, and then limit the traffic in/out of this pod. In this case, we’ll create a policy that identifies the tables that each client should be able to access, the actions that are allowed on those tables, and deny the rest.
As an example, a policy could limit containers with label app=empire-outpost to only be able to insert entries into the table “attendance.daily_reports”, but would block any attempt by a compromised outpost to read all attendance information or access other keyspaces.
Here is the CiliumNetworkPolicy rule that limits access of pods with label app=empire-outpost to only insert records into “attendance.daily_reports”:
apiVersion: "cilium.io/v2"
kind: CiliumNetworkPolicy
description: "Allow only permitted requests to empire Cassandra server"
metadata:
name: "secure-empire-cassandra"
specs:
- endpointSelector:
matchLabels:
app: cass-server
ingress:
- fromEndpoints:
- matchLabels:
app: empire-outpost
toPorts:
- ports:
- port: "9042"
protocol: TCP
rules:
l7proto: cassandra
l7:
- query_action: "select"
query_table: "system\\..*"
- query_action: "select"
query_table: "system_schema\\..*"
- query_action: "insert"
query_table: "attendance.daily_records"
- fromEndpoints:
- matchLabels:
app: empire-hq
toPorts:
- ports:
- port: "9042"
protocol: TCP
rules:
l7proto: cassandra
l7:
- {}
A CiliumNetworkPolicy contains a list of rules that define allowed requests, meaning that requests that do not match any rules are denied as invalid.
The rule explicitly matches Cassandra connections destined to TCP 9042 on cass-server pods, and allows query actions like select/insert/update/delete only on a specified set of tables. The above rule applies to inbound (i.e., “ingress”) connections to cass-server pods (as indicated by “app:cass-server” in the “endpointSelector” section). The rule applies different rules based on whether the client pod has labels “app: empire-outpost” or “app: empire-hq” as indicated by the “fromEndpoints” section.
The policy limits the empire-outpost pod to performing “select” queries on the “system” and “system_schema” keyspaces (required by cqlsh on startup) and “insert” queries to the “attendance.daily_records” table.
The full policy adds another rule that allows all queries from the empire-hq pod.
Apply this Cassandra-aware network security policy using kubectl in a new window:
$ kubectl create -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes-cassandra/cass-sw-security-policy.yaml
If we then again try to perform the attacks from the empire-outpost pod, we’ll see that they are denied:
$ cqlsh> SELECT * FROM attendance.daily_records;
Unauthorized: Error from server: code=2100 [Unauthorized] message="Request Unauthorized"
This is because the policy only permits pods with labels app: empire-outpost to insert into attendance.daily_records, it does not permit select on that table, or any action on other tables (with the exception of the system.* and system_schema.* keyspaces). Its worth noting that we don’t simply drop the message (which could easily be confused with a network error), but rather we respond with the Cassandra Unauthorized error message. (similar to how HTTP would return an error code of 403 unauthorized).
Likewise, if the outpost pod ever tries to access a table in another keyspace, like deathstar, this request will also be denied:
$ cqlsh> SELECT * FROM deathstar.scrum_notes;
Unauthorized: Error from server: code=2100 [Unauthorized] message="Request Unauthorized"
This is blocked as well, thanks to the Cilium network policy.
Use another window to confirm that the empire-hq pod still has full access to the cassandra cluster:
$ kubectl exec -it $HQ_POD cqlsh -- cassandra-svc
Connected to Test Cluster at cassandra-svc:9042.
[cqlsh 5.0.1 | Cassandra 3.11.3 | CQL spec 3.4.4 | Native protocol v4]
Use HELP for help.
cqlsh>
The power of Cilium’s identity-based security allows empire-hq to still have full access to both tables:
$ cqlsh> SELECT * FROM attendance.daily_records;
loc_id | creation | empire_member_id | present
--------------------------------------+--------------------------------------+--------------------------------------+---------
a855e745-69d8-4159-b8b6-e2bafed8387a | c692ce90-bf57-11e8-98e6-f1a9f45fc4d8 | cee6d956-dbeb-4b09-ad21-1dd93290fa6c | True
<snip>
(12 rows)
Similarly, the deathstar can still access the scrum notes:
$ cqlsh> SELECT * FROM deathstar.scrum_notes;
<snip>
(3 rows)
Cassandra-Aware Visibility (Bonus)¶
As a bonus, you can re-run the above queries with policy enforced and view how Cilium provides Cassandra-aware visibility, including whether requests are forwarded or denied. First, use “kubectl exec” to access the cilium pod.
$ CILIUM_POD=$(kubectl get pods -n kube-system -l k8s-app=cilium -o jsonpath='{.items[0].metadata.name}')
$ kubectl exec -it -n kube-system $CILIUM_POD /bin/bash
root@minikube:~#
Next, start Cilium monitor, and limit the output to only “l7” type messages using the “-t” flag:
root@minikube:~# cilium monitor -t l7
Listening for events on 2 CPUs with 64x4096 of shared memory
Press Ctrl-C to quit
In the other windows, re-run the above queries, and you will see that Cilium provides full visibility at the level of each Cassandra request, indicating:
- The Kubernetes label-based identity of both the sending and receiving pod.
- The details of the Cassandra request, including the ‘query_action’ (e.g., ‘select’, ‘insert’) and ‘query_table’ (e.g., ‘system.local’, ‘attendance.daily_records’)
- The ‘verdict’ indicating whether the request was allowed by policy (‘Forwarded’ or ‘Denied’).
Example output is below. All requests are from empire-outpost to cass-server. The first two requests are allowed, a ‘select’ into ‘system.local’ and an ‘insert’ into ‘attendance.daily_records’. The second two requests are denied, a ‘select’ into ‘attendance.daily_records’ and a select into ‘deathstar.scrum_notes’ :
<- Request cassandra from 0 ([k8s:io.cilium.k8s.policy.serviceaccount=default k8s:io.kubernetes.pod.namespace=default k8s:app=empire-outpost]) to 64503 ([k8s:app=cass-server k8s:io.kubernetes.pod.namespace=default k8s:io.cilium.k8s.policy.serviceaccount=default]), identity 12443->16168, verdict Forwarded query_table:system.local query_action:selec
<- Request cassandra from 0 ([k8s:io.cilium.k8s.policy.serviceaccount=default k8s:io.kubernetes.pod.namespace=default k8s:app=empire-outpost]) to 64503 ([k8s:app=cass-server k8s:io.kubernetes.pod.namespace=default k8s:io.cilium.k8s.policy.serviceaccount=default]), identity 12443->16168, verdict Forwarded query_action:insert query_table:attendance.daily_records
<- Request cassandra from 0 ([k8s:io.cilium.k8s.policy.serviceaccount=default k8s:io.kubernetes.pod.namespace=default k8s:app=empire-outpost]) to 64503 ([k8s:app=cass-server k8s:io.kubernetes.pod.namespace=default k8s:io.cilium.k8s.policy.serviceaccount=default]), identity 12443->16168, verdict Denied query_action:select query_table:attendance.daily_records
<- Request cassandra from 0 ([k8s:io.cilium.k8s.policy.serviceaccount=default k8s:io.kubernetes.pod.namespace=default k8s:app=empire-outpost]) to 64503 ([k8s:app=cass-server k8s:io.kubernetes.pod.namespace=default k8s:io.cilium.k8s.policy.serviceaccount=default]), identity 12443->16168, verdict Denied query_table:deathstar.scrum_notes query_action:select
Clean Up¶
You have now installed Cilium, deployed a demo app, and tested L7 Cassandra-aware network security policies. To clean up, run:
$ minikube delete
After this, you can re-run the tutorial from Step 1.
Getting Started Securing Memcached¶
This document serves as an introduction to using Cilium to enforce memcached-aware security policies. It walks through a single-node Cilium environment running on your machine. It is designed to take 15-30 minutes.
NOTE: memcached-aware policy support is still in beta. It is not yet ready for production use. Additionally, the memcached-specific policy language is highly likely to change in a future Cilium version.
Memcached is a high performance, distributed memory object caching system. It’s simple yet powerful, and used by dynamic web applications to alleviate database load. Memcached is designed to work efficiently for a very large number of open connections. Thus, clients are encouraged to cache their connections rather than the overhead of reopening TCP connections every time they need to store or retrieve data. Multiple clients can benefit from this distributed cache’s performance benefits.
There are two kinds of data sent in the memcache protocol: text lines and unstructured (binary) data. We will demonstrate clients using both types of protocols to communicate with a memcached server.
If you haven’t read the Introduction to Cilium yet, we’d encourage you to do that first.
The best way to get help if you get stuck is to ask a question on the Cilium Slack channel. With Cilium contributors across the globe, there is almost always someone available to help.
Setup Cilium¶
If you have not set up Cilium yet, pick any installation method as described in section Installation to set up Cilium for your Kubernetes environment. If in doubt, pick Getting Started Using Minikube as the simplest way to set up a Kubernetes cluster with Cilium.
Step 2: Deploy the Demo Application¶
Now that we have Cilium deployed and kube-dns operating correctly we can
deploy our demo memcached application. Since our first
HTTP-aware Cilium demo was based on Star Wars, we continue with the theme for the memcached demo as well.
Ever wonder how the Alliance Fleet manages the changing positions of their ships? The Alliance Fleet uses memcached to store the coordinates of their ships. The Alliance Fleet leverages the memcached-svc service implemented as a memcached server. Each ship in the fleet constantly updates its coordinates and has the ability to get the coordinates of other ships in the Alliance Fleet.
In this simple example, the Alliance Fleet uses a memcached server for their starfighters to store their own supergalatic coordinates and get those of other starfighters.
In order to avoid collisions and protect against compromised starfighters, memcached commands are limited to gets for any starfighter coordinates and sets only to a key specific to the starfighter. Thus the following operations are allowed:
- A-wing: can set coordinates to key “awing-coord” and get the key coordinates.
- X-wing: can set coordinates to key “xwing-coord” and get the key coordinates.
- Alliance-Tracker: can get any coordinates but not set any.
To keep the setup small, we will launch a small number of pods to represent a larger environment:
- memcached-server : A Kubernetes service represented by a single pod running a memcached server (label app=memcd-server).
- a-wing memcached binary client : A pod representing an A-wing starfighter, which can update its coordinates and read it via the binary memcached protocol (label app=a-wing).
- x-wing memcached text-based client : A pod representing an X-wing starfighter, which can update its coordinates and read it via the text-based memcached protocol (label app=x-wing).
- alliance-tracker memcached binary client : A pod representing the Alliance Fleet Tracker, able to read the coordinates of all starfighters (label name=fleet-tracker).
Memcached clients access the memcached-server on TCP port 11211 and send memcached protocol messages to it.
The file memcd-sw-app.yaml contains a Kubernetes Deployment for each of the pods described
above, as well as a Kubernetes Service memcached-server for the Memcached server.
$ kubectl create -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes-memcached/memcd-sw-app.yaml deployment.extensions/memcached-server created service/memcached-server created deployment.extensions/a-wing created deployment.extensions/x-wing created deployment.extensions/alliance-tracker created
Kubernetes will deploy the pods and service in the background.
Running kubectl get svc,pods will inform you about the progress of the operation.
Each pod will go through several states until it reaches Running at which
point the setup is ready.
$ kubectl get svc,pods
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 31m
service/memcached-server ClusterIP None <none> 11211/TCP 14m
NAME READY STATUS RESTARTS AGE
pod/a-wing-67db8d5fcc-dpwl4 1/1 Running 0 14m
pod/alliance-tracker-6b6447bd69-sz5hz 1/1 Running 0 14m
pod/memcached-server-bdbfb87cd-8tdh7 1/1 Running 0 14m
pod/x-wing-fd5dfb9d9-wrtwn 1/1 Running 0 14m
We suggest having a main terminal window to execute kubectl commands and two additional terminal windows dedicated to accessing the A-Wing and Alliance-Tracker, which use a python library to communicate to the memcached server using the binary protocol.
In all three terminal windows, set some handy environment variables for the demo with the following script:
In the terminal window dedicated for the A-wing pod, exec in, use python to import the binary memcached library and set the client connection to the memcached server:
$ kubectl exec -ti $AWING_POD sh
# python
Python 3.7.0 (default, Sep 5 2018, 03:25:31)
[GCC 6.3.0 20170516] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import bmemcached
>>> client = bmemcached.Client(("memcached-server:11211", ))
In the terminal window dedicated for the Alliance-Tracker, exec in, use python to import the binary memcached library and set the client connection to the memcached server:
$ kubectl exec -ti $TRACKER_POD sh
# python
Python 3.7.0 (default, Sep 5 2018, 03:25:31)
[GCC 6.3.0 20170516] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import bmemcached
>>> client = bmemcached.Client(("memcached-server:11211", ))
Step 3: Test Basic Memcached Access¶
Let’s show that each client is able to access the memcached server. Execute the following to have the A-wing and X-wing starfighters update the Alliance Fleet memcached-server with their respective supergalatic coordinates:
A-wing will access the memcached-server using the binary protocol. In your terminal window for A-Wing, set A-wing’s coordinates:
>>> client.set("awing-coord","4309.432,918.980",time=2400)
True
>>> client.get("awing-coord")
'4309.432,918.980'
In your main terminal window, have X-wing starfighter set their coordinates using the text-based protocol to the memcached server.
$ kubectl exec $XWING_POD sh -- -c "echo -en \"$SETXC\" | nc memcached-server 11211" STORED $ kubectl exec $XWING_POD sh -- -c "echo -en \"$GETXC\" | nc memcached-server 11211" VALUE xwing-coord 0 16 8893.34,234.3290 END
Check that the Alliance Fleet Tracker is able to get all starfighters’ coordinates in your terminal window for the Alliance-Tracker:
>>> client.get("awing-coord")
'4309.432,918.980'
>>> client.get("xwing-coord")
'8893.34,234.3290'
Step 4: The Danger of a Compromised Memcached Client¶
Imagine if a starfighter ship is captured. Should the starfighter be able to set the coordinates of other ships, or get the coordinates of all other ships? Or if the Alliance-Tracker is compromised, can it modify the coordinates of any starfighter ship? If every client has access to the Memcached API on port 11211, all have over-privileged access until further locked down.
With L4 port access to the memcached server, all starfighters could write to any key/ship and read all ship coordinates. In your main terminal, execute:
$ kubectl exec $XWING_POD sh -- -c "echo -en \"$GETAC\" | nc memcached-server 11211" VALUE awing-coord 0 16 4309.432,918.980 END
In your A-Wing terminal window, confirm the over-privileged access:
>>> client.get("xwing-coord")
'8893.34,234.3290'
>>> client.set("xwing-coord","0.0,0.0",time=2400)
True
>>> client.get("xwing-coord")
'0.0,0.0'
From A-Wing, set the X-Wing coordinates back to their proper position:
>>> client.set("xwing-coord","8893.34,234.3290",time=2400)
True
Thus, the Alliance Fleet Tracking System could be made weak if a single starfighter ship is compromised.
Step 5: Securing Access to Memcached with Cilium¶
Cilium helps lock down Memcached servers to ensure clients have secure access to it. Beyond just providing access to port 11211, Cilium can enforce specific key value access by understanding both the text-based and the unstructured (binary) memcached protocol.
We’ll create a policy that limits the scope of what a starfighter can access and write. Thus, only the intended memcached protocol calls to the memcached-server can be made.
In this example, we’ll only allow A-Wing to get and set the key “awing-coord”, only allow X-Wing to get and set key “xwing-coord”, and allow Alliance-Tracker to only get coordinates.
Here is the CiliumNetworkPolicy rule that limits the access of starfighters to their own key and allows Alliance Tracker to get any coordinate:
apiVersion: "cilium.io/v2"
kind: CiliumNetworkPolicy
metadata:
name: "secure-fleet"
spec:
endpointSelector:
matchLabels:
app: memcd-server
ingress:
- fromEndpoints:
- matchLabels:
app: a-wing
toPorts:
- ports:
- port: '11211'
protocol: TCP
rules:
l7proto: memcache
l7:
- command: get
keyExact: awing-coord
- command: set
keyExact: awing-coord
- fromEndpoints:
- matchLabels:
app: x-wing
toPorts:
- ports:
- port: '11211'
protocol: TCP
rules:
l7proto: memcache
l7:
- command: get
keyExact: xwing-coord
- command: set
keyExact: xwing-coord
- fromEndpoints:
- matchLabels:
name: fleet-tracker
toPorts:
- ports:
- port: '11211'
protocol: TCP
rules:
l7proto: memcache
l7:
- command: get
keyExact: awing-coord
- command: get
keyExact: xwing-coord
A CiliumNetworkPolicy contains a list of rules that define allowed memcached commands, and requests that do not match any rules are denied. The rules explicitly match connections destined to the Memcached Service on TCP 11211.
The rules apply to inbound (i.e., “ingress”) connections bound for memcached-server pods (as indicated by app:memcached-server
in the “endpointSelector” section). The rules apply differently depending on the
client pod: app:a-wing, app:x-wing, or name:fleet-tracker as indicated by the “fromEndpoints” section.
With the policy in place, A-wings can only get and set the key “awing-coord”; similarly the X-Wing can only get and set “xwing-coord”. The Alliance Tracker can only get coordinates - not set.
Apply this Memcached-aware network security policy using kubectl in your main terminal window:
$ kubectl create -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes-memcached/memcd-sw-security-policy.yaml
If we then try to perform the attacks from the X-wing pod from the main terminal window, we’ll see that they are denied:
$ kubectl exec $XWING_POD sh -- -c "echo -en \"$GETAC\" | nc memcached-server 11211" CLIENT_ERROR access denied
From the A-Wing terminal window, we can confirm that if A-wing goes outside of the bounds of its allowed calls. You may need to run the client.get command twice for the python call:
>>> client.get("awing-coord")
'4309.432,918.980'
>>> client.get("xwing-coord")
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/usr/local/lib/python3.7/site-packages/bmemcached/client/replicating.py", line 42, in get
value, cas = server.get(key)
File "/usr/local/lib/python3.7/site-packages/bmemcached/protocol.py", line 440, in get
raise MemcachedException('Code: %d Message: %s' % (status, extra_content), status)
bmemcached.exceptions.MemcachedException: ("Code: 8 Message: b'access denied'", 8)
Similarly, the Alliance-Tracker cannot set any coordinates, which you can attempt from the Alliance-Tracker terminal window:
>>> client.get("xwing-coord")
'8893.34,234.3290'
>>> client.set("awing-coord","0.0,0.0",time=1200)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/usr/local/lib/python3.7/site-packages/bmemcached/client/replicating.py", line 112, in set
returns.append(server.set(key, value, time, compress_level=compress_level))
File "/usr/local/lib/python3.7/site-packages/bmemcached/protocol.py", line 604, in set
return self._set_add_replace('set', key, value, time, compress_level=compress_level)
File "/usr/local/lib/python3.7/site-packages/bmemcached/protocol.py", line 583, in _set_add_replace
raise MemcachedException('Code: %d Message: %s' % (status, extra_content), status)
bmemcached.exceptions.MemcachedException: ("Code: 8 Message: b'access denied'", 8)
The policy is working as expected.
With the CiliumNetworkPolicy in place, the allowed Memcached calls are still allowed from the respective pods.
In the main terminal window, execute:
$ kubectl exec $XWING_POD sh -- -c "echo -en \"$GETXC\" | nc memcached-server 11211" VALUE xwing-coord 0 16 8893.34,234.3290 END $ SETXC="set xwing-coord 0 1200 16\r\n9854.34,926.9187\r\nquit\r\n" $ kubectl exec $XWING_POD sh -- -c "echo -en \"$SETXC\" | nc memcached-server 11211" STORED $ kubectl exec $XWING_POD sh -- -c "echo -en \"$GETXC\" | nc memcached-server 11211" VALUE xwing-coord 0 16 9854.34,926.9187 END
In the A-Wing terminal window, execute:
>>> client.set("awing-coord","9852.542,892.1318",time=1200)
True
>>> client.get("awing-coord")
'9852.542,892.1318'
>>> exit()
# exit
In the Alliance-Tracker terminal window, execute:
>>> client.get("awing-coord")
>>> client.get("xwing-coord")
>>> exit()
# exit
Step 7: Clean Up¶
You have now installed Cilium, deployed a demo app, and tested L7 memcached-aware network security policies. To clean up, in your main terminal window, run:
$ minikube delete
For some handy memcached references, see below:
Locking down external access using AWS metadata¶
This document serves as an introduction to using Cilium to enforce policies based on AWS instances metadata. It is a detailed walk-through of getting a single-node Cilium environment running on your machine. It is designed to take 15-30 minutes with some experience running Kubernetes.
Setup Cilium¶
This guide will work with any approach to installing Cilium, including minikube, as long as the cilium-operator pod in the deployment can reach the AWS API server However, since the most common use of this mechanism is for Kubernetes clusters running in AWS, we recommend trying it out along with the guide: Installation on AWS EKS .
Create AWS secrets¶
Before installing Cilium, a new Kubernetes Secret with the AWS Tokens needs to be added to your Kubernetes cluster. This Secret will allow Cilium to gather information from the AWS API which is needed to implement ToGroups policies.
AWS Access keys and IAM role¶
To create a new access token the following guide can be used. These keys need to have certain permissions set:
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": "ec2:Describe*",
"Resource": "*"
}
]
}
As soon as you have the access tokens, the following secret needs to be added, with each empty string replaced by the associated value as a base64-encoded string:
apiVersion: v1
kind: Secret
metadata:
name: cilium-aws
namespace: kube-system
type: Opaque
data:
AWS_ACCESS_KEY_ID: ""
AWS_SECRET_ACCESS_KEY: ""
AWS_DEFAULT_REGION: ""
The base64 command line utility can be used to generate each value, for example:
$ echo -n "eu-west-1" | base64
ZXUtd2VzdC0x
This secret stores the AWS credentials, which will be used to connect the AWS API.
$ kubectl create -f cilium-secret.yaml
To validate that the credentials are correct, the following pod can be created for debugging purposes:
apiVersion: v1
kind: Pod
metadata:
name: testing-aws-pod
namespace: kube-system
spec:
containers:
- name: aws-cli
image: mesosphere/aws-cli
command: ['sh', '-c', 'sleep 3600']
env:
- name: AWS_ACCESS_KEY_ID
valueFrom:
secretKeyRef:
name: cilium-aws
key: AWS_ACCESS_KEY_ID
optional: true
- name: AWS_SECRET_ACCESS_KEY
valueFrom:
secretKeyRef:
name: cilium-aws
key: AWS_SECRET_ACCESS_KEY
optional: true
- name: AWS_DEFAULT_REGION
valueFrom:
secretKeyRef:
name: cilium-aws
key: AWS_DEFAULT_REGION
optional: true
To list all of the available AWS instances, the following command can be used:
$ kubectl -n kube-system exec -ti testing-aws-pod -- aws ec2 describe-instances
Once the secret has been created and validated, the cilium-operator pod must be restarted in order to pick up the credentials in the secret. To do this, identify and delete the existing cilium-operator pod, which will be recreated automatically:
$ kubectl get pods -l name=cilium-operator -n kube-system
NAME READY STATUS RESTARTS AGE
cilium-operator-7c9d69f7c-97vqx 1/1 Running 0 36h
$ kubectl delete pod cilium-operator-7c9d69f7c-97vqx
It is important for this demo that coredns is working correctly. To know the
status of coredns you can run the following command:
$ kubectl get deployment kube-dns -n kube-system
NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE
coredns 2 2 2 2 13h
Where at least one pod should be available.
Configure AWS Security Groups¶
Cilium’s AWS Metadata filtering capability enables explicit whitelisting of communication between a subset of pods (identified by Kubernetes labels) with a set of destination EC2 VMs (identified by membership in an AWS security group).
In this example, the destination EC2 VMs are a member of a single AWS security group (‘sg-0f2146100a88d03c3’) and pods with label class=xwing should only be able to make connections outside the cluster to the destination VMs in that security group.
To enable this, the VMs acting as Kubernetes worker nodes must be able to send traffic to the destination VMs that are being accessed by pods. One approach for achieving this is to put all Kubernetes worker VMs in a single ‘k8s-worker’ security group, and then ensure that any security group that is referenced in a Cilium toGroups policy has an allow all ingress rule (all ports) for connections from the ‘k8s-worker’ security group. Cilium filtering will then ensure that the only pods allowed by policy can reach the destination VMs.
Create a sample policy¶
Deploy a demo application:¶
In this case we’re going to use a demo application that is used in other guides. These manifests will create three microservices applications: deathstar, tiefighter, and xwing. In this case, we are only going to use our xwing microservice to secure communications to existing AWS instances.
$ kubectl create -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/minikube/http-sw-app.yaml service "deathstar" created deployment "deathstar" created deployment "tiefighter" created deployment "xwing" created
Kubernetes will deploy the pods and service in the background. Running kubectl
get pods,svc will inform you about the progress of the operation. Each pod
will go through several states until it reaches Running at which point the
pod is ready.
$ kubectl get pods,svc
NAME READY STATUS RESTARTS AGE
po/deathstar-76995f4687-2mxb2 1/1 Running 0 1m
po/deathstar-76995f4687-xbgnl 1/1 Running 0 1m
po/tiefighter 1/1 Running 0 1m
po/xwing 1/1 Running 0 1m
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
svc/deathstar ClusterIP 10.109.254.198 <none> 80/TCP 3h
svc/kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 3h
Policy Language:¶
ToGroups rules can be used to define policy in relation to cloud providers, like AWS.
---
kind: CiliumNetworkPolicy
apiVersion: cilium.io/v2
metadata:
name: to-groups-sample
namespace: default
spec:
endpointSelector:
matchLabels:
org: alliance
class: xwing
egress:
- toPorts:
- ports:
- port: '80'
protocol: TCP
toGroups:
- aws:
securityGroupsIds:
- 'sg-0f2146100a88d03c3'
This policy allows traffic from pod xwing to any AWS instance that is in
the security group with ID sg-0f2146100a88d03c3.
Validate that derived policy is in place¶
Every time that a new policy with ToGroups rules is added, an equivalent policy (also called “derivative policy”), will be created. This policy will contain the set of CIDRs that correspond to the specification in ToGroups, e.g., the IPs of all instances that are part of a specified security group. The list of IPs will be updated periodically.
$ kubectl get cnp
NAME AGE
to-groups-sample 11s
to-groups-sample-togroups-044ba7d1-f491-11e8-ad2e-080027d2d952 10s
Eventually, the derivative policy will contain IPs in the ToCIDR section:
$ kubectl get cnp to-groups-sample-togroups-044ba7d1-f491-11e8-ad2e-080027d2d952
apiVersion: cilium.io/v2
kind: CiliumNetworkPolicy
metadata:
creationTimestamp: 2018-11-30T11:13:52Z
generation: 1
labels:
io.cilium.network.policy.kind: derivative
io.cilium.network.policy.parent.uuid: 044ba7d1-f491-11e8-ad2e-080027d2d952
name: to-groups-sample-togroups-044ba7d1-f491-11e8-ad2e-080027d2d952
namespace: default
ownerReferences:
- apiVersion: cilium.io/v2
blockOwnerDeletion: true
kind: CiliumNetworkPolicy
name: to-groups-sample
uid: 044ba7d1-f491-11e8-ad2e-080027d2d952
resourceVersion: "34853"
selfLink: /apis/cilium.io/v2/namespaces/default/ciliumnetworkpolicies/to-groups-sample-togroups-044ba7d1-f491-11e8-ad2e-080027d2d952
uid: 04b289ba-f491-11e8-ad2e-080027d2d952
specs:
- egress:
- toCIDRSet:
- cidr: 34.254.113.42/32
- cidr: 172.31.44.160/32
toPorts:
- ports:
- port: "80"
protocol: TCP
endpointSelector:
matchLabels:
any:class: xwing
any:org: alliance
k8s:io.kubernetes.pod.namespace: default
labels:
- key: io.cilium.k8s.policy.name
source: k8s
value: to-groups-sample
- key: io.cilium.k8s.policy.uid
source: k8s
value: 044ba7d1-f491-11e8-ad2e-080027d2d952
- key: io.cilium.k8s.policy.namespace
source: k8s
value: default
- key: io.cilium.k8s.policy.derived-from
source: k8s
value: CiliumNetworkPolicy
status:
nodes:
k8s1:
enforcing: true
lastUpdated: 2018-11-30T11:28:03.907678888Z
localPolicyRevision: 28
ok: true
The derivative rule should contain the following information:
- metadata.OwnerReferences: that contains the information about the ToGroups policy.
- specs.Egress.ToCIDRSet: the list of private and public IPs of the instances that correspond to the spec of the parent policy.
- status: whether or not the policy is enforced yet, and when the policy was last updated.
The Cilium Endpoint status for the xwing should have policy enforcement enabled only for egress connectivity:
$ kubectl get cep xwing
NAME ENDPOINT ID IDENTITY ID POLICY ENFORCEMENT ENDPOINT STATE IPV4 IPV6
xwing 23453 63929 egress ready 10.10.0.95 f00d::a0a:0:0:22cf
In this example, xwing pod can only connect to 34.254.113.42/32 and
172.31.44.160/32 and connectivity to other IP will be denied.
Advanced Networking¶
Using kube-router to run BGP¶
This guide explains how to configure Cilium and kube-router to co-operate to use kube-router for BGP peering and route propagation and Cilium for policy enforcement and load-balancing.
Note
This is a beta feature. Please provide feedback and file a GitHub issue if you experience any problems.
Deploy kube-router¶
Download the kube-router DaemonSet template:
curl -LO https://raw.githubusercontent.com/cloudnativelabs/kube-router/v0.2.0-beta.7/daemonset/generic-kuberouter-only-advertise-routes.yaml
Open the file generic-kuberouter-only-advertise-routes.yaml and edit the
args: section. The following arguments are requried to be set to
exactly these values:
- --run-router=true
- --run-firewall=false
- --run-service-proxy=false
- --enable-cni=false
- --enable-pod-egress=false
The following arguments are optional and may be set according to your needs. For the purpose of keeping this guide simple, the following values are being used which require the least preparations in your cluster. Please see the kube-router user guide for more information.
- --enable-ibgp=true
- --enable-overlay=true
- --advertise-cluster-ip=true
- --advertise-external-ip=true
- --advertise-loadbalancer-ip=true
The following arguments are optional and should be set if you want BGP peering with an external router. This is useful if you want externally routable Kubernetes Pod and Service IPs. Note the values used here should be changed to whatever IPs and ASNs are configured on your external router.
- --cluster-asn=65001
- --peer-router-ips=10.0.0.1,10.0.2
- --peer-router-asns=65000,65000
Apply the DaemonSet file to deploy kube-router and verify it has come up correctly:
$ kubectl apply -f generic-kuberouter-only-advertise-routes.yaml
$ kubectl -n kube-system get pods -l k8s-app=kube-router
NAME READY STATUS RESTARTS AGE
kube-router-n6fv8 1/1 Running 0 10m
kube-router-nj4vs 1/1 Running 0 10m
kube-router-xqqwc 1/1 Running 0 10m
kube-router-xsmd4 1/1 Running 0 10m
Deploy Cilium¶
In order for routing to be delegated to kube-router, tunneling/encapsulation
must be disabled. This is done by setting the tunnel=disabled in the
ConfigMap cilium-config or by adjusting the DaemonSet to run the
cilium-agent with the argument --tunnel=disabled:
# Encapsulation mode for communication between nodes
# Possible values:
# - disabled
# - vxlan (default)
# - geneve
tunnel: "disabled"
You can then install Cilium according to the instructions in section Requirements.
Ensure that Cilium is up and running:
$ kubectl -n kube-system get pods -l k8s-app=cilium
NAME READY STATUS RESTARTS AGE
cilium-fhpk2 1/1 Running 0 45m
cilium-jh6kc 1/1 Running 0 44m
cilium-rlx6n 1/1 Running 0 44m
cilium-x5x9z 1/1 Running 0 45m
Verify Installation¶
Verify that kube-router has installed routes:
$ kubectl -n kube-system exec -ti cilium-fhpk2 -- ip route list scope global
default via 172.0.32.1 dev eth0 proto dhcp src 172.0.50.227 metric 1024
10.2.0.0/24 via 10.2.0.172 dev cilium_host src 10.2.0.172
10.2.1.0/24 via 172.0.51.175 dev eth0 proto 17
10.2.2.0/24 dev tun-172011760 proto 17 src 172.0.50.227
10.2.3.0/24 dev tun-1720186231 proto 17 src 172.0.50.227
In the above example, we see three categories of routes that have been installed:
- Local PodCIDR: This route points to all pods running on the host and makes
these pods available to
*
10.2.0.0/24 via 10.2.0.172 dev cilium_host src 10.2.0.172 - BGP route: This type of route is installed if kube-router determines that
the remote PodCIDR can be reached via a router known to the local host. It
will instruct pod to pod traffic to be forwarded directly to that router
without requiring any encapsulation.
*
10.2.1.0/24 via 172.0.51.175 dev eth0 proto 17 - IPIP tunnel route: If no direct routing path exists, kube-router will fall
back to using an overlay and establish an IPIP tunnel between the nodes.
*
10.2.2.0/24 dev tun-172011760 proto 17 src 172.0.50.227*10.2.3.0/24 dev tun-1720186231 proto 17 src 172.0.50.227
You can test connectivity by deploying the following connectivity checker pods:
$ kubectl create -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/connectivity-check/connectivity-check.yaml $ kubectl get pods NAME READY STATUS RESTARTS AGE echo-7d9f9564df-2vbpw 1/1 Running 0 26m echo-7d9f9564df-ff8xh 1/1 Running 0 26m echo-7d9f9564df-pnbgc 1/1 Running 0 26m echo-7d9f9564df-sbrxh 1/1 Running 0 26m echo-7d9f9564df-wzfrc 1/1 Running 0 26m probe-8689f6579-7l7w7 1/1 Running 0 27m probe-8689f6579-fvqp8 1/1 Running 0 27m probe-8689f6579-lvjlh 1/1 Running 0 27m probe-8689f6579-m26g8 1/1 Running 0 27m probe-8689f6579-tzbjk 1/1 Running 0 27m
Setting up Cluster Mesh¶
This is a step-by-step guide on how to build a mesh of Kubernetes clusters by connecting them together, enabling pod-to-pod connectivity across all clusters, define global services to load-balance between clusters and enforce security policies to restrict access.
Prerequisites¶
- PodCIDR ranges in all clusters must be non-conflicting.
- This guide and the referenced scripts assume that Cilium was installed using the Standard Installation instructions which leads to etcd being managed by Cilium using etcd-operator. You can use any way to manage etcd but you will have to adjust some of the scripts to account for different secret names and adjust the LoadBalancer to expose the etcd pods.
- Nodes in all clusters must have IP connectivity between each other. This requirement is typically met by establishing peering or VPN tunnels between the networks of the nodes of each cluster.
- All nodes must have a unique IP address assigned them. Node IPs of clusters being connected together may not conflict with each other.
- Cilium must be configured to use etcd as the kvstore. Consul is not supported by cluster mesh at this point.
- It is highly recommended to use a TLS protected etcd cluster with Cilium. The
server certificate of etcd must whitelist the host name
*.mesh.cilium.io. If you are using thecilium-etcd-operatoras set up in the Standard Installation instructions then this is automatically taken care of. - The network between clusters must allow the inter-cluster communication. The exact ports are documented in the Firewall Rules section.
Prepare the clusters¶
Specify the cluster name and ID¶
Each cluster must be assigned a unique human-readable name. The name will be
used to group nodes of a cluster together. The cluster name is specified with
the --cluster-name=NAME argument or cluster-name ConfigMap option.
To ensure scalability of identity allocation and policy enforcement, each
cluster continues to manage its own security identity allocation. In order to
guarantee compatibility with identities across clusters, each cluster is
configured with a unique cluster ID configured with the --cluster-id=ID
argument or cluster-id ConfigMap option. The value must be between 1 and
255.
kubectl -n kube-system edit cm cilium-config
[ ... add/edit ... ]
cluster-name: cluster1
cluster-id: "1"
Repeat this step for each cluster.
Expose the Cilium etcd to other clusters¶
The Cilium etcd must be exposed to other clusters. There are many ways to
achieve this. The method documented in this guide will work with cloud
providers that implement the Kubernetes LoadBalancer service type:
apiVersion: v1
kind: Service
metadata:
name: cilium-etcd-external
annotations:
cloud.google.com/load-balancer-type: "Internal"
spec:
type: LoadBalancer
ports:
- port: 2379
selector:
app: etcd
etcd_cluster: cilium-etcd
io.cilium/app: etcd-operator
apiVersion: v1
kind: Service
metadata:
name: cilium-etcd-external
annotations:
service.beta.kubernetes.io/aws-load-balancer-internal: 0.0.0.0/0
spec:
type: LoadBalancer
ports:
- port: 2379
selector:
app: etcd
etcd_cluster: cilium-etcd
io.cilium/app: etcd-operator
The example used here exposes the etcd cluster as managed by
cilium-etcd-operator installed by the standard installation instructions as
an internal service which means that it is only exposed inside of a VPC and not
publicly accessible outside of the VPC. It is recommended to use a static IP
for the ServiceIP to avoid requiring to update the IP mapping as done in one of
the later steps.
If you are running the cilium-etcd-operator you can simply apply the following service to expose etcd:
kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/clustermesh/cilium-etcd-external-service/cilium-etcd-external-gke.yaml
kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/clustermesh/cilium-etcd-external-service/cilium-etcd-external-eks.yaml
Note
Make sure that you create the service in namespace in which cilium and/or
etcd is running. Depending on which installation method you chose, this
could be kube-system or cilium.
Extract the TLS keys and generate the etcd configuration¶
The cluster mesh control plane performs TLS based authentication and encryption. For this purpose, the TLS keys and certificates of each etcd need to be made available to all clusters that wish to connect.
Clone the
cilium/clustermesh-toolsrepository. It contains scripts to extracts the secrets and generate a Kubernetes secret in form of a YAML file:git clone https://github.com/cilium/clustermesh-tools.git cd clustermesh-tools
Ensure that the kubectl context is pointing to the cluster you want to extract the secret from.
Extract the TLS certificate, key and root CA authority.
./extract-etcd-secrets.sh
This will extract the keys that Cilium is using to connect to the etcd in the local cluster. The key files are written to
config/<cluster-name>.*.{key|crt|-ca.crt}Repeat this step for all clusters you want to connect with each other.
Generate a single Kubernetes secret from all the keys and certificates extracted. The secret will contain the etcd configuration with the service IP or host name of the etcd including the keys and certificates to access it.
./generate-secret-yaml.sh > clustermesh.yaml
Note
The key files in config/ and the secret represented as YAML are
sensitive. Anyone gaining access to these files is able to connect to the
etcd instances in the local cluster. Delete the files after the you are done
setting up the cluster mesh.
Ensure that the etcd service names can be resolved¶
For TLS authentication to work properly, agents will connect to etcd in remote
clusters using a pre-defined naming schema {clustername}.mesh.cilium.io. In
order for DNS resolution to work on these virtual host name, the names are
statically mapped to the service IP via the /etc/hosts file.
The following script will generate the required segment which has to be inserted into the
ciliumDaemonSet:./generate-name-mapping.sh > ds.patch
The
ds.patchwill look something like this:spec: template: spec: hostAliases: - ip: "10.138.0.18" hostnames: - cluster1.mesh.cilium.io - ip: "10.138.0.19" hostnames: - cluster2.mesh.cilium.io
Apply the patch to all DaemonSets in all clusters:
kubectl -n kube-system patch ds cilium -p "$(cat ds.patch)"
Establish connections between clusters¶
1. Import the cilium-clustermesh secret that you generated in the last
chapter into all of your clusters:
kubectl -n kube-system apply -f clustermesh.yaml
- Restart the cilium-agent in all clusters so it picks up the new cluster
name, cluster id and mounts the
cilium-clustermeshsecret. Cilium will automatically establish connectivity between the clusters.
kubectl -n kube-system delete pod -l k8s-app=cilium
- For global services to work (see below), also restart the cilium-operator:
kubectl -n kube-system delete pod -l name=cilium-operator
Test pod connectivity between clusters¶
Run cilium node list to see the full list of nodes discovered. You can run
this command inside any Cilium pod in any cluster:
$ kubectl -n kube-system exec -ti cilium-g6btl cilium node list
Name IPv4 Address Endpoint CIDR IPv6 Address Endpoint CIDR
cluster5/ip-172-0-117-60.us-west-2.compute.internal 172.0.117.60 10.2.2.0/24 <nil> f00d::a02:200:0:0/112
cluster5/ip-172-0-186-231.us-west-2.compute.internal 172.0.186.231 10.2.3.0/24 <nil> f00d::a02:300:0:0/112
cluster5/ip-172-0-50-227.us-west-2.compute.internal 172.0.50.227 10.2.0.0/24 <nil> f00d::a02:0:0:0/112
cluster5/ip-172-0-51-175.us-west-2.compute.internal 172.0.51.175 10.2.1.0/24 <nil> f00d::a02:100:0:0/112
cluster7/ip-172-0-121-242.us-west-2.compute.internal 172.0.121.242 10.4.2.0/24 <nil> f00d::a04:200:0:0/112
cluster7/ip-172-0-58-194.us-west-2.compute.internal 172.0.58.194 10.4.1.0/24 <nil> f00d::a04:100:0:0/112
cluster7/ip-172-0-60-118.us-west-2.compute.internal 172.0.60.118 10.4.0.0/24 <nil> f00d::a04:0:0:0/112
$ kubectl exec -ti pod-cluster5-xxx curl <pod-ip-cluster7>
[...]
Load-balancing with Global Services¶
Establishing load-balancing between clusters is achieved by defining a
Kubernetes service with identical name and namespace in each cluster and adding
the annotation io.cilium/global-service: "true"` to declare it global.
Cilium will automatically perform load-balancing to pods in both clusters.
apiVersion: v1
kind: Service
metadata:
name: rebel-base
annotations:
io.cilium/global-service: "true"
spec:
type: ClusterIP
ports:
- port: 80
selector:
name: rebel-base
Deploying a simple example service¶
In cluster 1, deploy:
kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/clustermesh/global-service-example/cluster1.yaml
In cluster 2, deploy:
kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/clustermesh/global-service-example/cluster2.yaml
From either cluster, access the global service:
kubectl exec -ti xwing-xxx -- curl rebel-base
You will see replies from pods in both clusters.
Security Policies¶
As addressing and network security is decoupled, network security enforcement
automatically spans across clusters. Note that Kubernetes security policies are
not automatically distributed across clusters, it is your responsibility to
apply CiliumNetworkPolicy or NetworkPolicy in all clusters.
Allowing specific communication between clusters¶
The following policy illustrates how to allow particular pods to allow
communicate between two clusters. The cluster name refers to the name given via
the --cluster-name agent option or cluster-name ConfigMap option.
apiVersion: "cilium.io/v2"
kind: CiliumNetworkPolicy
metadata:
name: "allow-cross-cluster"
description: "Allow x-wing in cluster1 to contact rebel-base in cluster2"
spec:
endpointSelector:
matchLabels:
name: x-wing
io.cilium.k8s.policy.cluster: cluster1
egress:
- toEndpoints:
- matchLabels:
name: rebel-base
io.cilium.k8s.policy.cluster: cluster2
Troubleshooting¶
Check the Cilium pod logs for
level=errorandlevel=warningmessages.Look for the following message to ensure that ClusterMesh is initialized:
level=info msg="Initializing ClusterMesh routing" path=/var/lib/cilium/clustermesh/ subsys=daemonAs remote clusters are discovered an info log message
New remote cluster discoveredalong with the remote cluster name is logged.Run a
kubectl exec -ti [...] bashin one of the Cilium pods and check the contents of the directory/var/lib/cilium/clustermesh/. It must contain a configuration file for each remote cluster along with all the required SSL certificates and keys. The filenames must match the cluster names as provided by the--cluster-nameargument orcluster-nameConfigMap option. If the directory is empty or incomplete, regenerate the secret again and ensure that the secret is correctly mounted into the DaemonSet.Run
cilium node listin one of the Cilium pods and validate that all nodes are discovered correctly. If the node discovery is not working, runcilium kvstore get --recursive cilium/state/nodes/v1/and check if an entry exists for each node.
When using global services, ensure that the
cilium-operatordeployment is running and healthy. It is responsible to propagate Kubernetes services into the kvstore. You can validate the correct functionality of the operator by running:cilium kvstore get --recursive cilium/state/services/v1/An entry must exist for each global service
You can confirm the correct propagation of service backend endpoints by running
cilium service listandcilium bpf lb listto see the complete mapping of service IPs to backend/pod IPs.Run
cilium debuginfoand look for the section “k8s-service-cache”. In that section, you will find the contents of the service correlation cache. it will list the Kubernetes services and endpoints of the local cluster. It will also have a sectionexternalEndpointswhich must list all endpoints of remote clusters.
Limitations¶
- L7 security policies currently only work across multiple clusters if worker nodes have routes installed allowing to route pod IPs of all clusters. This is given when running in direct routing mode by running a routing daemon or
--auto-direct-node-routesbut won’t work automatically when using tunnel/encapsulation mode.- The number of clusters that can be connected together is currently limited to 255. This limitation will be lifted in the future when running in direct routing mode or when running in encapsulation mode with encryption enabled.
Roadmap Ahead¶
- Future versions will put an API server before etcd to provide better scalability and simplify the installation to support any etcd support
- Introduction of IPSec and use of ESP or utilization of the traffic class field in the IPv6 header will allow to use more than 8 bits for the cluster-id and thus support more than 256 clusters.
Cilium integration with Flannel (beta)¶
This guide contains the necessary steps to run Cilium on top of your Flannel cluster.
If you have a cluster already set up with Flannel you will not need to install Flannel again.
This Cilium integration with Flannel was performed with Flannel 0.10.0 and Kubernetes >= 1.9. If you find any issues with previous Flannel versions please feel free to reach out to us to help you.
Flannel installation¶
NOTE: If kubeadm is used, then pass --pod-network-cidr=10.244.0.0/16 to
kubeadm init to ensure that the podCIDR is set.
kubectl -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/addons/flannel/flannel.yaml
Wait until all pods to be in ready state before preceding to the next step.
Cilium installation¶
Download Cilium kubernetes descriptor for your Kubernetes version.
curl -LO https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.15/cilium.yaml
curl -LO https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.14/cilium.yaml
curl -LO https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.13/cilium.yaml
curl -LO https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.12/cilium.yaml
curl -LO https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.11/cilium.yaml
curl -LO https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.10/cilium.yaml
Edit the ConfigMap in that file and set the option flannel-master-device with "cni0".
Set flannel-uninstall-on-exit with either true or false. If you
plan to deploy Cilium and ensure that policy enforcement will persist even if
you remove Cilium, then leave the option set to false. If you plan to test
Cilium in your cluster and remove Cilium once you have finished your tests,
setting the option with true will make sure the Cilium will clean up all BPF
programs generated for the host where Cilium was running.
Optional step:
If your cluster has already pods being managed by Flannel, there is also
an option available that allows Cilium to start managing those pods without
requiring to restart them. To enable this functionality you need to set the
value flannel-manage-existing-containers to true and modify
the hostPID value in the Cilium DaemonSet to true. Running
Cilium with hostPID is required because Cilium needs to access the network
namespaces of those already running pods in order to derive the MAC address and
IP address which allows the generation dedicated BPF programs for those pods.
# Interface to be used when running Cilium on top of a CNI plugin.
# For flannel, use "cni0"
flannel-master-device: "cni0"
# When running Cilium with policy enforcement enabled on top of a CNI plugin
# the BPF programs will be installed on the network interface specified in
# 'flannel-master-device' and on all network interfaces belonging to
# a container. When the Cilium DaemonSet is removed, the BPF programs will
# be kept in the interfaces unless this option is set to "true".
flannel-uninstall-on-exit: "false"
# Installs a BPF program to allow for policy enforcement in already running
# containers managed by Flannel.
# NOTE: This requires Cilium DaemonSet to be running in the hostPID.
# To run in this mode in Kubernetes change the value of the hostPID from
# false to true. Can be found under the path `spec.spec.hostPID`
flannel-manage-existing-containers: "false"
Once you have changed the ConfigMap accordingly, you can deploy Cilium.
kubectl create -f ./cilium.yaml
Cilium might not come up immediately on all nodes, since Flannel only sets up the bridge network interface that connects containers with the outside world when the first container is created on that node. In this case, Cilium will wait until that bridge is created before marking itself as Ready.
IPVLAN based Networking (beta)¶
This guide explains how to configure Cilium to set up an ipvlan-based datapath instead of the default veth-based one.
Note
This is a beta feature. Please provide feedback and file a GitHub issue if you experience any problems.
The feature lacks support of the following, which will be resolved in upcoming Cilium releases:
- IPVLAN L2 mode
- L7 policy enforcement
- NAT64
- IPVLAN with tunneling
Note
The ipvlan-based datapath in L3 mode requires v4.12 or more recent Linux kernel, while L3S mode, in addition, requires a stable kernel with the fix mentioned in this document (see below).
First step is to download the Cilium Kubernetes descriptor:
curl -LO https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.15/cilium.yaml
curl -LO https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.14/cilium.yaml
curl -LO https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.13/cilium.yaml
curl -LO https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.12/cilium.yaml
curl -LO https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.11/cilium.yaml
curl -LO https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.10/cilium.yaml
Edit the cilium-config ConfigMap in that file with the etcd server
that is running in your cluster and set the option datapath-mode to
"ipvlan".
It is also required to specify the ipvlan master device which typically
points to a networking device that is facing the external network. This
is done through setting ipvlan-master-device to the name of the
networking device such as "eth0" or "bond0", for example. Be
aware this ConfigMap will be used by all nodes, so it is required this
device name is consistent on all nodes where you are going to deploy
Cilium.
The ipvlan datapath only supports direct routing mode right now,
therefore tunneling must be disabled through setting tunnel to
"disabled".
To make ipvlan work between hosts, routes on each host have to be installed
either manually or automatically by Cilium. The latter can be enabled
through setting auto-direct-node-routes to "true".
The --install-iptables-rules parameter is optional and if set to
"false" then Cilium will not install any iptables rules which are
mainly for interaction with kube-proxy, and additionally it will trigger
ipvlan setup in L3 mode. For the default case where the latter is "true",
ipvlan is operated in L3S mode such that netfilter in host namespace
is not bypassed. Optionally, the agent can also be set up for masquerading
all traffic leaving the ipvlan master device if masquerade is set
to "true". Note that in order for L3S mode to work correctly, a kernel
with the following fix is required: d5256083f62e .
This fix is included in stable kernels v4.9.155, 4.14.98, 4.19.20,
4.20.6 or higher. Without this kernel fix, ipvlan in L3S mode cannot
connect to kube-apiserver.
Masquerading with iptables in L3-only mode is not possible since netfilter
hooks are bypassed in the kernel in this mode, hence L3S (symmetric) had
to be introduced in the kernel at the cost of performance. However, Cilium
supports its own BPF-based masquerading which does not rely in any way on
iptables masquerading. If the --install-iptables-rules parameter is set
to "false" and --masquerade set to "true", then Cilium will
use the more efficient BPF-based masquerading where ipvlan can remain in
L3 mode as well (instead of L3S). A Linux kernel v4.16 or higher would be
required for BPF-based masquerading.
Example ConfigMap extract for ipvlan in pure L3 mode:
datapath-mode: "ipvlan"
ipvlan-master-device: "bond0"
tunnel: "disabled"
install-iptables-rules: "false"
auto-direct-node-routes: "true"
Example ConfigMap extract for ipvlan in L3S mode with iptables masquerading all traffic leaving the node:
datapath-mode: "ipvlan"
ipvlan-master-device: "bond0"
tunnel: "disabled"
masquerade: "true"
auto-direct-node-routes: "true"
Example ConfigMap extract for ipvlan in L3 mode with more efficient BPF-based masquerading instead of iptables-based:
datapath-mode: "ipvlan"
ipvlan-master-device: "bond0"
tunnel: "disabled"
masquerade: "true"
install-iptables-rules: "false"
auto-direct-node-routes: "true"
Apply the DaemonSet file to deploy Cilium and verify that it has come up correctly:
kubectl create -f ./cilium.yaml
kubectl -n kube-system get pods -l k8s-app=cilium
NAME READY STATUS RESTARTS AGE
cilium-crf7f 1/1 Running 0 10m
For further information on Cilium’s ipvlan datapath mode, see Architecture.
Transparent Encryption (beta)¶
This guide explains how to configure Cilium to use IPSec based transparent encryption using Kubernetes secrets to distribute the IPSec keys. After this configuration is complete all traffic between Cilium managed endpoints, as well as Cilium managed host traffic, will be encrypted using IPSec. This guide uses Kubernetes secrets to distribute keys. Alternatively, keys may be manually distributed but that is not shown here.
Note
This is a beta feature. Please provide feedback and file a GitHub issue if you experience any problems.
Generate & import the PSK¶
First create a Kubernetes secret for the IPSec keys to be stored.
This will generate the necessary IPSec keys which will be distributed as a
Kubernetes secret called cilium-ipsec-keys. In this example we use
GCM-128-AES, but any of the supported
Linux algorithms may be used. To generate use the following
$ kubectl create -n kube-system secret generic cilium-ipsec-keys \
--from-literal=keys="3 rfc4106(gcm(aes)) $(echo $(dd if=/dev/urandom count=20 bs=1 2> /dev/null| xxd -p -c 64)) 128"
The secret can be displayed with kubectl -n kube-system get secret and will be
listed as ‘cilium-ipsec-keys’.
$ kubectl -n kube-system get secrets cilium-ipsec-keys
NAME TYPE DATA AGE
cilium-ipsec-keys Opaque 1 176m
Enable Encryption in Cilium¶
First step is to download the Cilium Kubernetes descriptor:
curl -LO https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.15/cilium-ds.yaml
curl -LO https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.14/cilium-ds.yaml
curl -LO https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.13/cilium-ds.yaml
curl -LO https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.12/cilium-ds.yaml
curl -LO https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.11/cilium-ds.yaml
curl -LO https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.10/cilium-ds.yaml
You can also use your existing definition DaemonSet running in your cluster:
kubectl -n kube-system get ds cilium -o yaml > cilium-ds.yaml
To enable encryption in Cilium, we use a patch file to update the configuration with the required cilium-agent options and included IPSec keys.
metadata:
namespace: kube-system
spec:
template:
spec:
containers:
- name: cilium-agent
args:
- "--debug=$(CILIUM_DEBUG)"
- "--kvstore=etcd"
- "--kvstore-opt=etcd.config=/var/lib/etcd-config/etcd.config"
- "--enable-ipsec"
- "--ipsec-key-file=/etc/ipsec/keys"
volumeMounts:
- name: cilium-ipsec-secrets
mountPath: /etc/ipsec
volumes:
- name: cilium-ipsec-secrets
secret:
secretName: cilium-ipsec-keys
If direct routing is being used an additional argument to identify the network facing interface is needed.
--encrypt-interface=ethX
The above shows the cilium-ipsec.yaml used with the following kubectl
patch command:
kubectl patch --filename='cilium-ds.yaml' --patch "$(cat cilium-ipsec.yaml)" --local -o yaml > cilium-ipsec-ds.yaml
Finally, apply the file,
kubectl apply -f cilium-ipsec-ds.yaml
At this point the Cilium managed nodes will be using IPSec for all traffic. For further information on Cilium’s transparent encryption, see Architecture.
Validate the Setup¶
Run a bash shell in one of the Cilium pods with kubectl -n kube-system
exec -ti cilium-7cpsm -- bash and execute the following commands:
- Install tcpdump
apt-get update
apt-get -y install tcpdump
- Check that traffic is encrypted:
tcpdump -n -i cilium_vxlan
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on cilium_vxlan, link-type EN10MB (Ethernet), capture size 262144 bytes
15:16:21.626416 IP 10.60.1.1 > 10.60.0.1: ESP(spi=0x00000001,seq=0x57e2), length 180
15:16:21.626473 IP 10.60.1.1 > 10.60.0.1: ESP(spi=0x00000001,seq=0x57e3), length 180
15:16:21.627167 IP 10.60.0.1 > 10.60.1.1: ESP(spi=0x00000001,seq=0x579d), length 100
15:16:21.627296 IP 10.60.0.1 > 10.60.1.1: ESP(spi=0x00000001,seq=0x579e), length 100
15:16:21.627523 IP 10.60.0.1 > 10.60.1.1: ESP(spi=0x00000001,seq=0x579f), length 180
15:16:21.627699 IP 10.60.1.1 > 10.60.0.1: ESP(spi=0x00000001,seq=0x57e4), length 100
15:16:21.628408 IP 10.60.1.1 > 10.60.0.1: ESP(spi=0x00000001,seq=0x57e5), length 100
Troubleshooting¶
Make sure that the Cilium pods have kvstore connectivity:
cilium status KVStore: Ok etcd: 1/1 connected: http://127.0.0.1:31079 - 3.3.2 (Leader) [...]Check for
level=warningandlevel=errormessages in the Cilium log filesRun a
bashin a Cilium and validate the following:
Routing rules matching on fwmark:
ip rule list 1: from all fwmark 0xd00/0xf00 lookup 200 1: from all fwmark 0xe00/0xf00 lookup 200 [...]Content of routing table 200
ip route list table 200 local 10.60.0.0/24 dev cilium_vxlan proto 50 scope host 10.60.1.0/24 via 10.60.0.1 dev cilium_hostXFRM policy:
ip xfrm p src 10.60.1.1/24 dst 10.60.0.1/24 dir fwd priority 0 mark 0xd00/0xf00 tmpl src 10.60.1.1 dst 10.60.0.1 proto esp spi 0x00000001 reqid 1 mode tunnel src 10.60.1.1/24 dst 10.60.0.1/24 dir in priority 0 mark 0xd00/0xf00 tmpl src 10.60.1.1 dst 10.60.0.1 proto esp spi 0x00000001 reqid 1 mode tunnel src 10.60.0.1/24 dst 10.60.1.1/24 dir out priority 0 mark 0xe00/0xf00 tmpl src 10.60.0.1 dst 10.60.1.1 proto esp spi 0x00000001 reqid 1 mode tunnelXFRM state:
ip xfrm s src 10.60.0.1 dst 10.60.1.1 proto esp spi 0x00000001 reqid 1 mode tunnel replay-window 0 auth-trunc hmac(sha256) 0x6162636465666768696a6b6c6d6e6f70717273747576777a797a414243444546 96 enc cbc(aes) 0x6162636465666768696a6b6c6d6e6f70717273747576777a797a414243444546 anti-replay context: seq 0x0, oseq 0xe0c0, bitmap 0x00000000 sel src 0.0.0.0/0 dst 0.0.0.0/0 src 10.60.1.1 dst 10.60.0.1 proto esp spi 0x00000001 reqid 1 mode tunnel replay-window 0 auth-trunc hmac(sha256) 0x6162636465666768696a6b6c6d6e6f70717273747576777a797a414243444546 96 enc cbc(aes) 0x6162636465666768696a6b6c6d6e6f70717273747576777a797a414243444546 anti-replay context: seq 0x0, oseq 0x0, bitmap 0x00000000 sel src 0.0.0.0/0 dst 0.0.0.0/0
Disabling Encryption¶
To disable the encryption, edit the DaemonSet and remove the --enable-ipsec
argument.
Operations¶
Running Prometheus & Grafana¶
Installation¶
This is an example deployment that includes Prometheus, Kube-metrics and Grafana in a single deployment.
The default installation contains:
- Kube-metrics: A metrics system to export Kubernetes data to Prometheus.
- Grafana: A visualization dashboard with Cilium Dashboard pre-loaded.
- Prometheus: A time series database and monitoring system.
$ kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/addons/prometheus/monitoring-example.yaml configmap/cilium-metrics-config created namespace/monitoring created clusterrolebinding.rbac.authorization.k8s.io/kube-state-metrics created clusterrole.rbac.authorization.k8s.io/kube-state-metrics created deployment.apps/kube-state-metrics created rolebinding.rbac.authorization.k8s.io/kube-state-metrics created role.rbac.authorization.k8s.io/kube-state-metrics-resizer created serviceaccount/kube-state-metrics created service/kube-state-metrics created configmap/prometheus created deployment.extensions/prometheus created service/prometheus created service/prometheus-open created clusterrolebinding.rbac.authorization.k8s.io/prometheus created clusterrole.rbac.authorization.k8s.io/prometheus created serviceaccount/prometheus-k8s created configmap/grafana-config created deployment.extensions/grafana created service/grafana created configmap/grafana-dashboards created job.batch/grafana-dashboards-import created
How to access¶
Prometheus and Grafana are available to access from outside cluster on different ports:
- Grafana:
<anyNodeIP>:31000 - Prometheus:
<anyNodeIP>:31001
Istio¶
Getting Started Using Istio¶
This document serves as an introduction to using Cilium to enforce security policies in Kubernetes micro-services managed with Istio. It is a detailed walk-through of getting a single-node Cilium + Istio environment running on your machine.
If you haven’t read the Introduction to Cilium yet, we’d encourage you to do that first.
The best way to get help if you get stuck is to ask a question on the Cilium Slack channel. With Cilium contributors across the globe, there is almost always someone available to help.
Setup Cilium¶
If you have not set up Cilium yet, pick any installation method as described in section Installation to set up Cilium for your Kubernetes environment. If in doubt, pick Getting Started Using Minikube as the simplest way to set up a Kubernetes cluster with Cilium.
Note
If running on minikube, you may need to up the memory and CPUs
available to the minikube VM from the defaults and/or the
instructions provided here for the other GSGs. 5 GB and 4 CPUs
should be enough for this GSG (--memory=5120 --cpus=4).
Step 2: Install Istio¶
Note
Make sure that Cilium is running in your cluster before proceeding.
Install the Helm client.
Download Istio version 1.2.5:
$ export ISTIO_VERSION=1.2.5
$ curl -L https://git.io/getLatestIstio | sh -
$ export ISTIO_HOME=`pwd`/istio-${ISTIO_VERSION}
$ export PATH="$PATH:${ISTIO_HOME}/bin"
Create a copy of Istio’s Helm charts in order to customize them:
$ cp -r ${ISTIO_HOME}/install/kubernetes/helm/istio istio-cilium-helm
Configure the Cilium-specific variant of Pilot to inject the Cilium network policy filters into each Istio sidecar proxy:
$ curl -s https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes-istio/cilium-pilot.awk > cilium-pilot.awk
$ awk -f cilium-pilot.awk \
< ${ISTIO_HOME}/install/kubernetes/helm/istio/charts/pilot/templates/deployment.yaml \
> istio-cilium-helm/charts/pilot/templates/deployment.yaml
Configure the Istio’s sidecar injection to setup the transparent proxy mode (TPROXY) as required by Cilium’s proxy filters:
$ sed -e 's,#interceptionMode: .*,interceptionMode: TPROXY,' \
< ${ISTIO_HOME}/install/kubernetes/helm/istio/templates/configmap.yaml \
> istio-cilium-helm/templates/configmap.yaml
Modify the Istio sidecar injection template to add an init container that waits until DNS works and to mount Cilium’s API Unix domain sockets into each sidecar to allow Cilium’s Envoy filters to query the Cilium agent for policy configuration:
$ curl -s https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes-istio/cilium-kube-inject.awk > cilium-kube-inject.awk
$ awk -f cilium-kube-inject.awk \
< ${ISTIO_HOME}/install/kubernetes/helm/istio/files/injection-template.yaml \
> istio-cilium-helm/files/injection-template.yaml
Create an Istio deployment spec, which configures the Cilium-specific variant of Pilot, and disables unused services:
$ helm template istio-cilium-helm --name istio --namespace istio-system \
--set pilot.image=docker.io/cilium/istio_pilot:${ISTIO_VERSION} \
--set sidecarInjectorWebhook.enabled=false \
--set global.controlPlaneSecurityEnabled=true \
--set global.mtls.enabled=true \
--set global.proxy.image=docker.io/cilium/istio_proxy:${ISTIO_VERSION} \
--set ingress.enabled=false \
--set egressgateway.enabled=false \
> istio-cilium.yaml
Deploy Istio onto Kubernetes:
$ kubectl create namespace istio-system
$ helm template ${ISTIO_HOME}/install/kubernetes/helm/istio-init --name istio-init --namespace istio-system | kubectl apply -f -
Verify that 23 Istio CRDs have been created:
$ watch "kubectl get crds | grep 'istio.io\|certmanager.k8s.io' | wc -l"
Note
This will get stuck at 0 if Cilium is not running in your cluster!
When the above returns ‘23’, you can stop it with CTRL-c and deploy Istio:
$ kubectl apply -f istio-cilium.yaml
Check the progress of the deployment (every service should have an
AVAILABLE count of 1):
$ watch "kubectl get deployments -n istio-system"
NAME READY UP-TO-DATE AVAILABLE AGE
istio-citadel 1/1 1 1 3m20s
istio-galley 1/1 1 1 3m20s
istio-ingressgateway 1/1 1 1 3m20s
istio-pilot 1/1 1 1 3m20s
istio-policy 1/1 1 1 3m20s
istio-telemetry 1/1 1 1 3m20s
prometheus 1/1 1 1 3m20s
Once all Istio pods are ready, we are ready to install the demo application.
Step 3: Deploy the Bookinfo Application V1¶
Now that we have Cilium and Istio deployed, we can deploy version
v1 of the services of the Istio Bookinfo sample application.
While the upstream Istio Bookinfo Application example for Kubernetes deploys multiple versions of the Bookinfo application at the same time, here we first deploy only the version 1.
The BookInfo application is broken into four separate microservices:
- productpage. The productpage microservice calls the details and reviews microservices to populate the page.
- details. The details microservice contains book information.
- reviews. The reviews microservice contains book reviews. It also calls the ratings microservice.
- ratings. The ratings microservice contains book ranking information that accompanies a book review.
In this demo, each specific version of each microservice is deployed into Kubernetes using separate YAML files which define:
- A Kubernetes Service.
- A Kubernetes Deployment specifying the microservice’s pods, specific to each service version.
- A Cilium Network Policy limiting the traffic to the microservice, specific to each service version.
To deploy the application with manual sidecar injection, run:
$ for service in productpage-service productpage-v1 details-v1 reviews-v1; do \
curl -s https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes-istio/bookinfo-${service}.yaml | \
istioctl kube-inject -f - | \
kubectl create --validate=false -f - ; done
service/productpage created
ciliumnetworkpolicy.cilium.io/productpage-v1 created
deployment.extensions/productpage-v1 created
service/details created
ciliumnetworkpolicy.cilium.io/details-v1 created
deployment.extensions/details-v1 created
service/reviews created
ciliumnetworkpolicy.cilium.io/reviews-v1 created
deployment.extensions/reviews-v1 created
Check the progress of the deployment (every service should have an
AVAILABLE count of 1):
$ watch "kubectl get deployments"
NAME READY UP-TO-DATE AVAILABLE AGE
details-v1 1/1 1 1 12s
productpage-v1 1/1 1 1 13s
reviews-v1 1/1 1 1 12s
Once all the pods are available, verify that the application works by making a query from reviews pod to the productpage:
Note
‘sudo’ here is needed to cause the curl connection to be forwarded to the proxy. Without it the connection is considered as coming from the proxy itself, causing the destination proxy to close the connection on (missing) TLS handshake failure.
$ kubectl exec -it $(kubectl get pod -l app=reviews -o jsonpath='{.items[0].metadata.name}') -c istio-proxy -- sudo curl productpage:9080/productpage | grep "<title>.*</title>"
<title>Simple Bookstore App</title>
Create an Istio ingress gateway for the productpage service:
$ kubectl apply -f ${ISTIO_HOME}/samples/bookinfo/networking/bookinfo-gateway.yaml
gateway "bookinfo-gateway" created
virtualservice "bookinfo" created
To obtain the URL to the frontend productpage service, run:
$ export GATEWAY_URL=http://$(minikube ip):$(kubectl -n istio-system get service istio-ingressgateway -o jsonpath='{.spec.ports[?(@.name=="http2")].nodePort}')
$ export PRODUCTPAGE_URL=${GATEWAY_URL}/productpage
$ echo "Open URL: ${PRODUCTPAGE_URL}"
Open that URL in your web browser and check that the application has been successfully deployed. It may take several seconds before all services become accessible in the Istio service mesh, so you may have have to reload the page.
Step 4: Canary and Deploy the Reviews Service V2¶
We will now deploy version v2 of the reviews service. In
addition to providing reviews from readers, reviews v2 queries a
new ratings service for book ratings, and displays each rating as
1 to 5 black stars.
As a precaution, we will use Istio’s service routing feature to canary
the v2 deployment to prevent breaking the end-to-end application
completely if it is faulty.
Before deploying v2, to prevent any traffic from being routed to
it for now, we will create this Istio route rules to route 100% of the
reviews traffic to v1:
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
name: reviews
spec:
hosts:
- reviews
http:
- route:
- destination:
host: reviews
subset: v1
weight: 100
---
apiVersion: networking.istio.io/v1alpha3
kind: DestinationRule
metadata:
name: reviews
spec:
host: reviews
trafficPolicy:
tls:
mode: ISTIO_MUTUAL
subsets:
- name: v1
labels:
version: v1
- name: v2
labels:
version: v2
Apply this route rule:
$ curl -s https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes-istio/route-rule-reviews-v1.yaml | \
kubectl apply -f -
virtualservice.networking.istio.io/reviews created
destinationrule.networking.istio.io/reviews created
Deploy the ratings v1 and reviews v2 services:
$ for service in ratings-v1 reviews-v2; do \
curl -s https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes-istio/bookinfo-${service}.yaml | \
istioctl kube-inject -f - | \
kubectl create --validate=false -f - ; done
service/ratings created
ciliumnetworkpolicy.cilium.io/ratings-v1 created
deployment.extensions/ratings-v1 created
ciliumnetworkpolicy.cilium.io/reviews-v2 created
deployment.extensions/reviews-v2 created
Check the progress of the deployment (every service should have an
AVAILABLE count of 1):
$ watch "kubectl get deployments"
NAME READY UP-TO-DATE AVAILABLE AGE
details-v1 1/1 1 1 17m
productpage-v1 1/1 1 1 17m
ratings-v1 1/1 1 1 69s
reviews-v1 1/1 1 1 17m
reviews-v2 1/1 1 1 68s
Check in your web browser that no stars are appearing in the Book
Reviews, even after refreshing the page several times. This indicates
that all reviews are retrieved from reviews v1 and none from
reviews v2.
The ratings-v1 CiliumNetworkPolicy explicitly whitelists access
to the ratings API only from productpage and reviews v2:
apiVersion: cilium.io/v2
kind: CiliumNetworkPolicy
metadata:
name: ratings-v1
namespace: default
specs:
- endpointSelector:
matchLabels:
"k8s:app": ratings
"k8s:version": v1
ingress:
- fromEndpoints:
- matchLabels:
"k8s:app": productpage
"k8s:version": v1
toPorts:
- ports:
- port: "9080"
protocol: TCP
rules:
http:
- method: GET
path: "/ratings/[0-9]*"
- fromEndpoints:
- matchLabels:
"k8s:app": reviews
"k8s:version": v2
toPorts:
- ports:
- port: "9080"
protocol: TCP
rules:
http:
- method: GET
path: "/ratings/[0-9]*"
Check that reviews v1 may not be able to access the ratings
service, even if it were compromised or suffered from a bug, by
running curl from within the pod:
Note
All traffic from reviews v1 to ratings is blocked, so the
connection attempt fails after the connection timeout.
$ export POD_REVIEWS_V1=`kubectl get pods -l app=reviews,version=v1 -o jsonpath='{.items[0].metadata.name}'`
$ kubectl exec ${POD_REVIEWS_V1} -c istio-proxy -ti -- curl --connect-timeout 5 --fail http://ratings:9080/ratings/0
curl: (28) Connection timed out after 5001 milliseconds
command terminated with exit code 28
Update the Istio route rule to send 50% of reviews traffic to
v1 and 50% to v2:
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
name: reviews
spec:
hosts:
- reviews
http:
- route:
- destination:
host: reviews
subset: v1
weight: 50
- destination:
host: reviews
subset: v2
weight: 50
Apply this route rule:
$ curl -s https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes-istio/route-rule-reviews-v1-v2.yaml | \
kubectl apply -f -
virtualservice.networking.istio.io/reviews configured
Check in your web browser that stars are appearing in the Book Reviews
roughly 50% of the time. This may require refreshing the page for a
few seconds to observe. Queries to reviews v2 result in reviews
containing ratings displayed as black stars:
Finally, update the route rule to send 100% of reviews traffic to
v2:
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
name: reviews
spec:
hosts:
- reviews
http:
- route:
- destination:
host: reviews
subset: v2
weight: 100
Apply this route rule:
$ curl -s https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes-istio/route-rule-reviews-v2.yaml | \
kubectl apply -f -
virtualservice.networking.istio.io/reviews configured
Refresh the product page in your web browser several times to verify
that stars are now appearing in the Book Reviews on every page
refresh. All the reviews are now retrieved from reviews v2 and
none from reviews v1.
Step 5: Deploy the Product Page Service V2¶
We will now deploy version v2 of the productpage service,
which brings two changes:
- It is deployed with a more restrictive CiliumNetworkPolicy, which restricts access to a subset of the HTTP URLs, at Layer-7.
- It implements a new authentication audit log into Kafka.
The policy for v1 currently allows read access to the full HTTP
REST API, under the /api/v1 HTTP URI path:
/api/v1/products: Returns the list of books and their details./api/v1/products/<id>: Returns details about a specific book./api/v1/products/<id>/reviews: Returns reviews for a specific book./api/v1/products/<id>/ratings: Returns ratings for a specific book.
Check that the full REST API is currently accessible in v1 and
returns valid JSON data:
$ for APIPATH in /api/v1/products /api/v1/products/0 /api/v1/products/0/reviews /api/v1/products/0/ratings; do echo ; curl -s -S "${GATEWAY_URL}${APIPATH}" ; echo ; done
[{"descriptionHtml": "<a href=\"https://en.wikipedia.org/wiki/The_Comedy_of_Errors\">Wikipedia Summary</a>: The Comedy of Errors is one of <b>William Shakespeare's</b> early plays. It is his shortest and one of his most farcical comedies, with a major part of the humour coming from slapstick and mistaken identity, in addition to puns and word play.", "id": 0, "title": "The Comedy of Errors"}]
{"publisher": "PublisherA", "language": "English", "author": "William Shakespeare", "id": 0, "ISBN-10": "1234567890", "ISBN-13": "123-1234567890", "year": 1595, "type": "paperback", "pages": 200}
{"reviews": [{"reviewer": "Reviewer1", "rating": {"color": "black", "stars": 5}, "text": "An extremely entertaining play by Shakespeare. The slapstick humour is refreshing!"}, {"reviewer": "Reviewer2", "rating": {"color": "black", "stars": 4}, "text": "Absolutely fun and entertaining. The play lacks thematic depth when compared to other plays by Shakespeare."}], "id": "0"}
{"ratings": {"Reviewer2": 4, "Reviewer1": 5}, "id": 0}
We realized that the REST API to get the book reviews and ratings was
meant only for consumption by other internal services, and will be
blocked from external clients using the updated Layer-7
CiliumNetworkPolicy in productpage v2, i.e. only the
/api/v1/products and /api/v1/products/<id> HTTP URLs will be
whitelisted:
apiVersion: cilium.io/v2
kind: CiliumNetworkPolicy
metadata:
name: productpage-v2
namespace: default
specs:
- endpointSelector:
matchLabels:
"k8s:app": productpage
"k8s:version": v2
ingress:
- toPorts:
- ports:
- port: "9080"
protocol: TCP
rules:
http:
- method: GET
path: "/"
- method: GET
path: "/index.html"
- method: POST
path: "/login"
- method: GET
path: "/logout"
- method: GET
path: "/productpage"
- method: GET
path: "/api/v1/products"
- method: GET
path: "/api/v1/products/[0-9]*"
# - method: GET
# path: "/api/v1/products/[0-9]*/reviews"
# - method: GET
# path: "/api/v1/products/[0-9]*/ratings"
Because productpage v2 sends messages into Kafka, we must first
deploy a Kafka broker:
$ curl -s https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes-istio/kafka-v1-destrule.yaml | \
kubectl create -f -
destinationrule.networking.istio.io/kafka-disable-mtls created
$ kubectl create -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes-istio/kafka-v1.yaml service/kafka created ciliumnetworkpolicy.cilium.io/kafka-authaudit created statefulset.apps/kafka-v1 created
Wait until the kafka-v1-0 pod is ready, i.e. until it has a
READY count of 1/1:
$ watch "kubectl get pods -l app=kafka"
NAME READY STATUS RESTARTS AGE
kafka-v1-0 1/1 Running 0 21m
Create the authaudit Kafka topic, which will be used by
productpage v2:
$ kubectl exec kafka-v1-0 -c kafka -- bash -c '/opt/kafka_2.11-0.10.1.0/bin/kafka-topics.sh --zookeeper localhost:2181/kafka --create --topic authaudit --partitions 1 --replication-factor 1'
Created topic "authaudit".
We are now ready to deploy productpage v2.
Create the productpage v2 service and its updated
CiliumNetworkPolicy and delete productpage v1:
$ curl -s https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes-istio/bookinfo-productpage-v2.yaml | \
istioctl kube-inject -f - | \
kubectl create --validate=false -f -
ciliumnetworkpolicy.cilium.io/productpage-v2 created
deployment.extensions/productpage-v2 created
$ kubectl delete -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes-istio/bookinfo-productpage-v1.yaml ciliumnetworkpolicy.cilium.io "productpage-v1" deleted deployment.extensions "productpage-v1" deleted
productpage v2 implements an authorization audit logging. On
every user login or logout, it produces into Kafka topic authaudit
a JSON-formatted message which contains the following information:
- event:
loginorlogout - username
- client IP address
- timestamp
To observe the Kafka messages sent by productpage, we will run an
additional authaudit-logger service. This service fetches and
prints out all messages from the authaudit Kafka topic. Start
this service:
$ curl -s https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes-istio/authaudit-logger-v1.yaml | \
istioctl kube-inject -f - | \
kubectl apply --validate=false -f -
deployment.extensions/authaudit-logger-v1 created
Check the progress of the deployment (every service should have an
AVAILABLE count of 1):
$ watch "kubectl get deployments"
NAME READY UP-TO-DATE AVAILABLE AGE
authaudit-logger-v1 1/1 1 1 41s
details-v1 1/1 1 1 37m
productpage-v2 1/1 1 1 4m47s
ratings-v1 1/1 1 1 20m
reviews-v1 1/1 1 1 37m
reviews-v2 1/1 1 1 20m
Check that the product REST API is still accessible, and that Cilium now denies at Layer-7 any access to the reviews and ratings REST API:
$ for APIPATH in /api/v1/products /api/v1/products/0 /api/v1/products/0/reviews /api/v1/products/0/ratings; do echo ; curl -s -S "${GATEWAY_URL}${APIPATH}" ; echo ; done
[{"descriptionHtml": "<a href=\"https://en.wikipedia.org/wiki/The_Comedy_of_Errors\">Wikipedia Summary</a>: The Comedy of Errors is one of <b>William Shakespeare's</b> early plays. It is his shortest and one of his most farcical comedies, with a major part of the humour coming from slapstick and mistaken identity, in addition to puns and word play.", "id": 0, "title": "The Comedy of Errors"}]
{"publisher": "PublisherA", "language": "English", "author": "William Shakespeare", "id": 0, "ISBN-10": "1234567890", "ISBN-13": "123-1234567890", "year": 1595, "type": "paperback", "pages": 200}
Access denied
Access denied
This demonstrated that requests to the
/api/v1/products/<id>/reviews and
/api/v1/products/<id>/ratings URIs now result in Cilium returning
HTTP 403 Forbidden HTTP responses.
Every login and logout on the product page will result in a line in
this service’s log. Note that you need to log in/out using the sign
in/sign out element on the bookinfo web page. When you do, you
can observe these kind of audit logs:
$ export POD_LOGGER_V1=`kubectl get pods -l app=authaudit-logger,version=v1 -o jsonpath='{.items[0].metadata.name}'`
$ kubectl logs ${POD_LOGGER_V1} -c authaudit-logger
...
{"timestamp": "2017-12-04T09:34:24.341668", "remote_addr": "10.15.28.238", "event": "login", "user": "richard"}
{"timestamp": "2017-12-04T09:34:40.943772", "remote_addr": "10.15.28.238", "event": "logout", "user": "richard"}
{"timestamp": "2017-12-04T09:35:03.096497", "remote_addr": "10.15.28.238", "event": "login", "user": "gilfoyle"}
{"timestamp": "2017-12-04T09:35:08.777389", "remote_addr": "10.15.28.238", "event": "logout", "user": "gilfoyle"}
As you can see, the user-identifiable information sent by
productpage in every Kafka message is sensitive, so access to this
Kafka topic must be protected using Cilium. The CiliumNetworkPolicy
configured on the Kafka broker enforces that:
- only
productpage v2is allowed to produce messages into theauthaudittopic; - only
authaudit-loggercan fetch messages from this topic; - no service can access any other topic.
apiVersion: "cilium.io/v2"
kind: CiliumNetworkPolicy
metadata:
name: kafka-authaudit
specs:
- endpointSelector:
matchLabels:
"k8s:app": kafka
ingress:
- fromEndpoints:
- matchLabels:
"k8s:app": productpage
"k8s:version": v2
toPorts:
- ports:
- port: "9092"
protocol: TCP
rules:
kafka:
- apiKey: "produce"
topic: "authaudit"
- apiKey: "apiversions"
- apiKey: "metadata"
- apiKey: "heartbeat"
- fromEndpoints:
- matchLabels:
app: kafka
- fromEndpoints:
- matchLabels:
"k8s:app": authaudit-logger
toPorts:
- ports:
- port: "9092"
protocol: TCP
rules:
kafka:
- apiKey: "fetch"
topic: "authaudit"
- apiKey: "apiversions"
- apiKey: "metadata"
- apiKey: "findcoordinator"
- apiKey: "joingroup"
- apiKey: "leavegroup"
- apiKey: "syncgroup"
- apiKey: "offsets"
- apiKey: "offsetcommit"
- apiKey: "offsetfetch"
- apiKey: "heartbeat"
Check that Cilium prevents the authaudit-logger service from
writing into the authaudit topic (enter a message followed by
ENTER, e.g. test message)
Note
Note that the error message may take a short time to appear.
Note
You can terminate the command with a single <CTRL>-d.
$ kubectl exec ${POD_LOGGER_V1} -c authaudit-logger -ti -- /opt/kafka_2.11-0.10.1.0/bin/kafka-console-producer.sh --broker-list=kafka:9092 --topic=authaudit
test message
[2017-12-07 02:13:47,020] ERROR Error when sending message to topic authaudit with key: null, value: 12 bytes with error: (org.apache.kafka.clients.producer.internals.ErrorLoggingCallback)
org.apache.kafka.common.errors.TopicAuthorizationException: Not authorized to access topics: [authaudit]
This demonstrated that Cilium sent a response with an authorization
error for any Produce request from this service.
Create another topic named credit-card-payments, meant to transmit
highly-sensitive credit card payment requests:
$ kubectl exec kafka-v1-0 -c kafka -- bash -c '/opt/kafka_2.11-0.10.1.0/bin/kafka-topics.sh --zookeeper localhost:2181/kafka --create --topic credit-card-payments --partitions 1 --replication-factor 1'
Created topic "credit-card-payments".
Check that Cilium prevents the authaudit-logger service from
fetching messages from this topic:
$ kubectl exec ${POD_LOGGER_V1} -c authaudit-logger -ti -- /opt/kafka_2.11-0.10.1.0/bin/kafka-console-consumer.sh --bootstrap-server=kafka:9092 --topic=credit-card-payments
[2017-12-07 03:08:54,513] WARN Not authorized to read from topic credit-card-payments. (org.apache.kafka.clients.consumer.internals.Fetcher)
[2017-12-07 03:08:54,517] ERROR Error processing message, terminating consumer process: (kafka.tools.ConsoleConsumer$)
org.apache.kafka.common.errors.TopicAuthorizationException: Not authorized to access topics: [credit-card-payments]
Processed a total of 0 messages
This demonstrated that Cilium sent a response with an authorization
error for any Fetch request from this service for any topic other
than authaudit.
Note
At present, the above command may also result in an error message.
Step 6: Clean Up¶
You have now installed Cilium and Istio, deployed a demo app, and tested both Cilium’s L3-L7 network security policies and Istio’s service route rules. To clean up, run:
$ minikube delete
After this, you can re-run the tutorial from Step 0.
Other Orchestrators¶
Cilium with Docker & libnetwork¶
This tutorial leverages Vagrant and VirtualBox, thus should run on any operating system supported by Vagrant, including Linux, macOS, and Windows.
Step 0: Install Vagrant¶
If you don’t already have Vagrant installed, refer to the Developer / Contributor Guide for links to installation instructions for Vagrant.
Step 1: Download the Cilium Source Code¶
Download the latest Cilium source code and unzip the files.
Alternatively, if you are a developer, feel free to clone the repository:
$ git clone https://github.com/cilium/cilium
Step 2: Starting the Docker + Cilium VM¶
Open a terminal and navigate into the top of the cilium source directory.
Then navigate into examples/getting-started and run vagrant up:
$ cd examples/getting-started
$ vagrant up
The script usually takes a few minutes depending on the speed of your internet connection. Vagrant will set up a VM, install the Docker container runtime and run Cilium with the help of Docker Compose. When the script completes successfully, it will print:
==> cilium-1: Creating cilium-kvstore
==> cilium-1: Creating cilium
==> cilium-1: Creating cilium-docker-plugin
$
If the script exits with an error message, do not attempt to proceed with the tutorial, as later steps will not work properly. Instead, contact us on the Cilium Slack channel.
Step 3: Accessing the VM¶
After the script has successfully completed, you can log into the VM using
vagrant ssh:
$ vagrant ssh
All commands for the rest of the tutorial below should be run from inside this
Vagrant VM. If you end up disconnecting from this VM, you can always reconnect
in a new terminal window just by running vagrant ssh again from the Cilium
directory.
Step 4: Confirm that Cilium is Running¶
The Cilium agent is now running as a system service and you can interact with
it using the cilium CLI client. Check the status of the agent by running
cilium status:
$ cilium status
KVStore: Ok Consul: 172.18.0.2:8300
ContainerRuntime: Ok
Kubernetes: Disabled
Cilium: Ok OK
NodeMonitor: Listening for events on 1 CPUs with 64x4096 of shared memory
Cilium health daemon: Ok
Controller Status: 6/6 healthy
Proxy Status: OK, ip 10.15.28.238, port-range 10000-20000
Cluster health: 1/1 reachable (2018-04-05T16:08:22Z)
The status indicates that all components are operational with the Kubernetes integration currently being disabled.
Step 5: Create a Docker Network of Type Cilium¶
Cilium integrates with local container runtimes, which in the case of this demo means Docker. With Docker, native networking is handled via a component called libnetwork. In order to steer Docker to request networking of a container from Cilium, a container must be started with a network of driver type “cilium”.
With Cilium, all containers are connected to a single logical network, with isolation added not based on IP addresses but based on container labels (as we will do in the steps below). So with Docker, we simply create a single network named ‘cilium-net’ for all containers:
$ docker network create --ipv6 --subnet ::1/112 --driver cilium --ipam-driver cilium cilium-net
Step 6: Start an Example Service with Docker¶
In this tutorial, we’ll use a container running a simple HTTP server to represent a microservice application which we will refer to as app1. As a result, we will start this container with the label “id=app1”, so we can create Cilium security policies for that service.
Use the following command to start the app1 container connected to the Docker network managed by Cilium:
$ docker run -d --name app1 --net cilium-net -l "id=app1" cilium/demo-httpd
e5723edaa2a1307e7aa7e71b4087882de0250973331bc74a37f6f80667bc5856
This has launched a container running an HTTP server which Cilium is now managing as an Endpoint. A Cilium endpoint is one or more application containers which can be addressed by an individual IP address.
Step 7: Apply an L3/L4 Policy With Cilium¶
When using Cilium, endpoint IP addresses are irrelevant when defining security policies. Instead, you can use the labels assigned to the VM to define security policies, which are automatically applied to any container with that label, no matter where or when it is run within a container cluster.
We’ll start with an overly simple example where we create two additional apps, app2 and app3, and we want app2 containers to be able to reach app1 containers, but app3 containers should not be allowed to reach app1 containers. Additionally, we only want to allow app1 to be reachable on port 80, but no other ports. This is a simple policy that filters only on IP address (network layer 3) and TCP port (network layer 4), so it is often referred to as an L3/L4 network security policy.
Cilium performs stateful ‘’connection tracking’‘, meaning that if a policy allows app2 to contact app1, it will automatically allow return packets that are part of app1 replying to app2 within the context of the same TCP/UDP connection.
L4 Policy with Cilium and Docker
We can achieve that with the following Cilium policy:
[{
"labels": [{"key": "name", "value": "l3-rule"}],
"endpointSelector": {"matchLabels":{"id":"app1"}},
"ingress": [{
"fromEndpoints": [
{"matchLabels":{"id":"app2"}}
],
"toPorts": [{
"ports": [{"port": "80", "protocol": "TCP"}]
}]
}]
}]
Save this JSON to a file named l3_l4_policy.json in your VM, and apply the policy by running:
$ cilium policy import l3_l4_policy.json
Revision: 1
Step 8: Test L3/L4 Policy¶
You can now launch additional containers that represent other services attempting to access app1. Any new container with label “id=app2” will be allowed to access app1 on port 80, otherwise the network request will be dropped.
To test this out, we’ll make an HTTP request to app1 from a container with the label “id=app2” :
$ docker run --rm -ti --net cilium-net -l "id=app2" cilium/demo-client curl -m 20 http://app1
<html><body><h1>It works!</h1></body></html>
We can see that this request was successful, as we get a valid HTTP response.
Now let’s run the same HTTP request to app1 from a container that has label “id=app3”:
$ docker run --rm -ti --net cilium-net -l "id=app3" cilium/demo-client curl -m 10 http://app1
You will see no reply as all packets are dropped by the Cilium security policy. The request will time-out after 10 seconds.
So with this we see Cilium’s ability to segment containers based purely on a container-level identity label. This means that the end user can apply security policies without knowing anything about the IP address of the container or requiring some complex mechanism to ensure that containers of a particular service are assigned an IP address in a particular range.
Step 9: Apply and Test an L7 Policy with Cilium¶
In the simple scenario above, it was sufficient to either give app2 / app3 full access to app1’s API or no access at all. But to provide the strongest security (i.e., enforce least-privilege isolation) between microservices, each service that calls app1’s API should be limited to making only the set of HTTP requests it requires for legitimate operation.
- For example, consider a scenario where app1 has two API calls:
- GET /public
- GET /private
Continuing with the example from above, if app2 requires access only to the GET /public API call, the L3/L4 policy alone has no visibility into the HTTP requests, and therefore would allow any HTTP request from app2 (since all HTTP is over port 80).
To see this, run:
$ docker run --rm -ti --net cilium-net -l "id=app2" cilium/demo-client curl 'http://app1/public'
{ 'val': 'this is public' }
and
$ docker run --rm -ti --net cilium-net -l "id=app2" cilium/demo-client curl 'http://app1/private'
{ 'val': 'this is private' }
Cilium is capable of enforcing HTTP-layer (i.e., L7) policies to limit what URLs app2 is allowed to reach. Here is an example policy file that extends our original policy by limiting app2 to making only a GET /public API call, but disallowing all other calls (including GET /private).
L7 Policy with Cilium and Docker
The following Cilium policy file achieves this goal:
[{
"labels": [{"key": "name", "value": "l7-rule"}],
"endpointSelector": {"matchLabels":{"id":"app1"}},
"ingress": [{
"fromEndpoints": [
{"matchLabels":{"id":"app2"}}
],
"toPorts": [{
"ports": [{"port": "80", "protocol": "TCP"}],
"rules": {
"http": [{
"method": "GET",
"path": "/public"
}]
}
}]
}]
}]
Create a file with this contents and name it l7_aware_policy.json. Then import this policy to Cilium by running:
$ cilium policy delete --all
Revision: 2
$ cilium policy import l7_aware_policy.json
Revision: 3
$ docker run --rm -ti --net cilium-net -l "id=app2" cilium/demo-client curl -si 'http://app1/public'
HTTP/1.1 200 OK
Accept-Ranges: bytes
Content-Length: 28
Date: Tue, 31 Oct 2017 14:30:56 GMT
Etag: "1c-54bb868cec400"
Last-Modified: Mon, 27 Mar 2017 15:58:08 GMT
Server: Apache/2.4.25 (Unix)
Content-Type: text/plain; charset=utf-8
{ 'val': 'this is public' }
and
$ docker run --rm -ti --net cilium-net -l "id=app2" cilium/demo-client curl -si 'http://app1/private'
HTTP/1.1 403 Forbidden
Content-Type: text/plain; charset=utf-8
X-Content-Type-Options: nosniff
Date: Tue, 31 Oct 2017 14:31:09 GMT
Content-Length: 14
Access denied
As you can see, with Cilium L7 security policies, we are able to permit app2 to access only the required API resources on app1, thereby implementing a “least privilege” security approach for communication between microservices.
We hope you enjoyed the tutorial. Feel free to play more with the setup, read the rest of the documentation, and reach out to us on the Cilium Slack channel with any questions!
Step 10: Clean-Up¶
Exit the vagrant VM by typing exit.
When you are done with the setup and want to tear-down the Cilium + Docker VM, and destroy all local state (e.g., the VM disk image), open a terminal in the cilium/examples/getting-started directory and type:
$ vagrant destroy cilium-1
You can always re-create the VM using the steps described above.
If instead you just want to shut down the VM but may use it later,
vagrant halt cilium-1 will work, and you can start it again later.
Cilium with Mesos/Marathon¶
This tutorial leverages Vagrant and VirtualBox to deploy Apache Mesos, Marathon and Cilium. You will run Cilium to apply a simple policy between a simulated web-service and clients. This tutorial can be run on any operating system supported by Vagrant including Linux, macOS, and Windows.
For more information on Apache Mesos and Marathon orchestration, check out the Mesos and Marathon GitHub pages, respectively.
Step 0: Install Vagrant¶
You need to run at least Vagrant version 1.8.3 or you will run into issues
booting the Ubuntu 17.04 base image. You can verify by running vagrant
--version.
If you don’t already have Vagrant installed, follow the Vagrant Install Instructions or see Download Vagrant for newer versions.
Step 1: Download the Cilium Source Code¶
Download the latest Cilium source code and unzip the files.
Alternatively, if you are a developer, feel free to clone the repository:
$ git clone https://github.com/cilium/cilium
Step 2: Starting a VM with Cilium¶
Open a terminal and navigate into the top of the cilium source directory.
Then navigate into examples/mesos and run vagrant up:
$ cd examples/mesos
$ vagrant up
The script usually takes a few minutes depending on the speed of your internet connection. Vagrant will set up a VM, install Mesos & Marathon, run Cilium with the help of Docker compose, and start up the Mesos master and slave services. When the script completes successfully, it will print:
==> default: Creating cilium-kvstore
Creating cilium-kvstore ... done
==> default: Creating cilium ...
==> default: Creating cilium
Creating cilium ... done
==> default: Installing loopback driver...
==> default: Installing cilium-cni to /host/opt/cni/bin/ ...
==> default: Installing new /host/etc/cni/net.d/00-cilium.conf ...
==> default: Deploying Vagrant VM + Cilium + Mesos...done
$
If the script exits with an error message, do not attempt to proceed with the tutorial, as later steps will not work properly. Instead, contact us on the Cilium Slack channel.
Step 3: Accessing the VM¶
After the script has successfully completed, you can log into the VM using
vagrant ssh:
$ vagrant ssh
All commands for the rest of the tutorial below should be run from inside this
Vagrant VM. If you end up disconnecting from this VM, you can always reconnect
by going to the examples/mesos directory and then running the command vagrant ssh.
Step 4: Confirm that Cilium is Running¶
The Cilium agent is now running and you can interact with it using the
cilium CLI client. Check the status of the agent by running cilium
status:
$ cilium status
KVStore: Ok Consul: 172.18.0.2:8300
ContainerRuntime: Ok docker daemon: OK
Kubernetes: Disabled
Cilium: Ok OK
NodeMonitor: Disabled
Cilium health daemon: Ok
IPv4 address pool: 3/65535 allocated
IPv6 address pool: 2/65535 allocated
Controller Status: 10/10 healthy
Proxy Status: OK, ip 10.15.0.1, port-range 10000-20000
Cluster health: 1/1 reachable (2018-06-19T15:10:28Z)
The status indicates that all necessary components are operational.
Step 5: Run Script to Start Marathon¶
Start Marathon inside the Vagrant VM:
$ ./start_marathon.sh
Starting marathon...
...
...
...
...
Done
Step 6: Simulate a Web-Server and Clients¶
Use curl to submit a task to Marathon for scheduling, with data to run the
simulated web-server provided by the web-server.json. The web-server simply
responds to requests on a particular port.
$ curl -i -H 'Content-Type: application/json' -d @web-server.json 127.0.0.1:8080/v2/apps
You should see output similar to the following:
HTTP/1.1 201 Created
...
Marathon-Deployment-Id: [UUID]
...
Confirm that Cilium sees the new workload. The output should return the
endpoint with label mesos:id=web-server and the assigned IP:
$ cilium endpoint list
ENDPOINT POLICY (ingress) POLICY (egress) IDENTITY LABELS (source:key[=value]) IPv6 IPv4 STATUS
ENFORCEMENT ENFORCEMENT
20928 Disabled Disabled 59281 mesos:id=web-server f00d::a0f:0:0:51c0 10.15.137.206 ready
23520 Disabled Disabled 4 reserved:health f00d::a0f:0:0:5be0 10.15.162.64 ready
Test the web-server provides OK output:
$ export WEB_IP=`cilium endpoint list | grep web-server | awk '{print $7}'`
$ curl $WEB_IP:8181/api
OK
Run a script to create two client tasks (“good client” and “bad client”) that
will attempt to access the web-server. The output of these tasks will be used
to validate the Cilium network policy enforcement later in the exercise. The
script will generate goodclient.json and badclient.json files for the
client tasks, respectively:
$ ./generate_client_file.sh goodclient
$ ./generate_client_file.sh badclient
Then submit the client tasks to Marathon, which will generate GET /public and GET /private requests:
$ curl -i -H 'Content-Type: application/json' -d @goodclient.json 127.0.0.1:8080/v2/apps
$ curl -i -H 'Content-Type: application/json' -d @badclient.json 127.0.0.1:8080/v2/apps
You can observe the newly created endpoints in Cilium, similar to the following output:
$ cilium endpoint list
ENDPOINT POLICY (ingress) POLICY (egress) IDENTITY LABELS (source:key[=value]) IPv6 IPv4 STATUS
ENFORCEMENT ENFORCEMENT
20928 Disabled Disabled 59281 mesos:id=web-server f00d::a0f:0:0:51c0 10.15.137.206 ready
23520 Disabled Disabled 4 reserved:health f00d::a0f:0:0:5be0 10.15.162.64 ready
37835 Disabled Disabled 15197 mesos:id=goodclient f00d::a0f:0:0:93cb 10.15.152.208 ready
51053 Disabled Disabled 5113 mesos:id=badclient f00d::a0f:0:0:c76d 10.15.34.97 ready
Marathon runs the tasks as batch jobs with stdout logged to task-specific
files located in /var/lib/mesos. To simplify the retrieval of the
stdout log, use the tail_client.sh script to output each of the client
logs. In a new terminal, go to examples/mesos, start a new ssh session to
the Vagrant VM with vagrant ssh and tail the goodclient logs:
$ ./tail_client.sh goodclient
and in a separate terminal, do the same thing with vagrant ssh and observe the badclient logs:
$ ./tail_client.sh badclient
Make sure both tail logs continuously prints the result of the clients accessing the /public and /private API of the web-server:
...
---------- Test #X ----------
Request: GET /public
Reply: OK
Request: GET /private
Reply: OK
-------------------------------
...
Note that both clients are able to access the web-server and retrieve both URLs because no Cilium policy has been applied yet.
Step 7: Apply L3/L4 Policy with Cilium¶
Apply an L3/L4 policy only allowing the goodclient to access the web-server. The L3/L4 json policy looks like:
[{
"labels": [{"key": "name", "value": "l3-l4-rule"}],
"endpointSelector": {"matchLabels":{"id":"web-server"}},
"ingress": [{
"fromEndpoints": [
{"matchLabels":{"id":"goodclient"}}
],
"toPorts": [{
"ports": [{"port": "8181", "protocol": "TCP"}]
}]
}]
}]
In your original terminal session, use cilium CLI to apply the L3/L4 policy above, saved in the l3-l4-policy.json file on the VM:
$ cilium policy import l3-l4-policy.json
Revision: 1
L3/L4 Policy with Cilium and Mesos
You can observe that the policy is applied via cilium CLI as the POLICY ENFORCEMENT column changed from Disabled to Enabled:
$ cilium endpoint list
ENDPOINT POLICY (ingress) POLICY (egress) IDENTITY LABELS (source:key[=value]) IPv6 IPv4 STATUS
ENFORCEMENT ENFORCEMENT
20928 Enabled Disabled 59281 mesos:id=web-server f00d::a0f:0:0:51c0 10.15.137.206 ready
23520 Disabled Disabled 4 reserved:health f00d::a0f:0:0:5be0 10.15.162.64 ready
37835 Disabled Disabled 15197 mesos:id=goodclient f00d::a0f:0:0:93cb 10.15.152.208 ready
51053 Disabled Disabled 5113 mesos:id=badclient f00d::a0f:0:0:c76d 10.15.34.97 ready
You should also observe that the goodclient logs continue to output the web-server responses, whereas the badclient request does not reach the web-server because of policy enforcement, and logging output similar to below.
...
---------- Test #X ----------
Request: GET /public
Reply: Timeout!
Request: GET /private
Reply: Timeout!
-------------------------------
...
Remove the L3/L4 policy in order to give badclient access to the web-server again.
$ cilium policy delete --all
Revision: 2
The badclient logs should resume outputting the web-server’s response and Cilium is configured to no longer enforce policy:
$ cilium endpoint list
ENDPOINT POLICY (ingress) POLICY (egress) IDENTITY LABELS (source:key[=value]) IPv6 IPv4 STATUS
ENFORCEMENT ENFORCEMENT
29898 Disabled Disabled 37948 reserved:health f00d::a0f:0:0:74ca 10.15.242.54 ready
33115 Disabled Disabled 38072 mesos:id=web-server f00d::a0f:0:0:815b 10.15.220.6 ready
38061 Disabled Disabled 46430 mesos:id=badclient f00d::a0f:0:0:94ad 10.15.0.173 ready
64189 Disabled Disabled 31645 mesos:id=goodclient f00d::a0f:0:0:fabd 10.15.152.27 ready
Step 8: Apply L7 Policy with Cilium¶
Now, apply an L7 Policy that only allows access for the goodclient to the /public API, included in the l7-policy.json file:
[{
"labels": [{"key": "name", "value": "l7-rule"}],
"endpointSelector": {"matchLabels":{"id":"web-server"}},
"ingress": [{
"fromEndpoints": [
{"matchLabels":{"id":"goodclient"}}
],
"toPorts": [{
"ports": [{"port": "8181", "protocol": "TCP"}],
"rules": {
"http": [{
"method": "GET",
"path": "/public"
}]
}
}]
}]
}]
Apply using cilium CLI:
$ cilium policy import l7-policy.json
Revision: 3
L7 Policy with Cilium and Mesos
In the terminal sessions tailing the goodclient and badclient logs, check the goodclient’s log to see that /private is no longer accessible, and the badclient’s requests are the same results as the enforced policy in the previous step.
...
---------- Test #X ----------
Request: GET /public
Reply: OK
Request: GET /private
Reply: Access Denied
-------------------------------
...
(optional) Remove the policy and notice that the access to /private is unrestricted again:
$ cilium policy delete --all
Revision: 4
Step 9: Clean-Up¶
Exit the vagrant VM by typing exit in original terminal session. When you want to tear-down the Cilium + Mesos VM and destroy all local state (e.g., the VM disk image), ensure you are in the cilium/examples/mesos directory and type:
$ vagrant destroy
You can always re-create the VM using the steps described above.
If instead you just want to shut down the VM but may use it later,
vagrant halt default will work, and you can start it again later.
Troubleshooting¶
For assistance on any of the Getting Started Guides, please reach out and ask a question on the Cilium Slack channel.
The best way to get help if you get stuck is to ask a question on the Cilium Slack channel. With Cilium contributors across the globe, there is almost always someone available to help.
Concepts¶
The goal of this document is to describe the components of the Cilium architecture, and the different models for deploying Cilium within your datacenter or cloud environment. It focuses on the higher-level understanding required to run a full Cilium deployment.
Component Overview¶
A deployment of Cilium consists of the following components running on each Linux container node in the container cluster:
- Cilium Agent (Daemon): Userspace daemon that interacts with the container runtime and orchestration systems such as Kubernetes via Plugins to setup networking and security for containers running on the local server. Provides an API for configuring network security policies, extracting network visibility data, etc.
- Cilium CLI Client: Simple CLI client for communicating with the local Cilium Agent, for example, to configure network security or visibility policies.
- Linux Kernel BPF: Integrated capability of the Linux kernel to accept compiled bytecode that is run at various hook / trace points within the kernel. Cilium compiles BPF programs and has the kernel run them at key points in the network stack to have visibility and control over all network traffic in / out of all containers.
- Container Platform Network Plugin: Each container platform (e.g., Docker, Kubernetes) has its own plugin model for how external networking platforms integrate. In the case of Docker, each Linux node runs a process (cilium-docker) that handles each Docker libnetwork call and passes data / requests on to the main Cilium Agent.
In addition to these components, Cilium also depends on the following components running in the cluster:
- Key-Value Store: Cilium shares data between Cilium Agents on different nodes via a kvstore. The currently supported key-value stores are etcd or consul.
- Cilium Operator: Daemon for handling cluster management duties which can be handled once per cluster, rather than once per node.
Cilium Agent¶
The Cilium agent (cilium-agent) runs on each Linux container host. At a high-level, the agent accepts configuration that describes service-level network security and visibility policies. It then listens to events in the container runtime to learn when containers are started or stopped, and it creates custom BPF programs which the Linux kernel uses to control all network access in / out of those containers. In more detail, the agent:
- Exposes APIs to allow operations / security teams to configure security policies (see below) that control all communication between containers in the cluster. These APIs also expose monitoring capabilities to gain additional visibility into network forwarding and filtering behavior.
- Gathers metadata about each new container that is created. In particular, it queries identity metadata like container / pod labels, which are used to identify Endpoint in Cilium security policies.
- Interacts with the container platforms network plugin to perform IP address management (IPAM), which controls what IPv4 and IPv6 addresses are assigned to each container. The IPAM is managed by the agent in a shared pool between all plugins which means that the Docker and CNI network plugin can run side by side allocating a single address pool.
- Combines its knowledge about container identity and addresses with the already configured security and visibility policies to generate highly efficient BPF programs that are tailored to the network forwarding and security behavior appropriate for each container.
- Compiles the BPF programs to bytecode using clang/LLVM and passes them to the Linux kernel to run for all packets in / out of the container’s virtual ethernet device(s).
Cilium CLI Client¶
The Cilium CLI Client (cilium) is a command-line tool that is installed along with the Cilium Agent. It gives a command-line interface to interact with all aspects of the Cilium Agent API. This includes inspecting Cilium’s state about each network endpoint (i.e., container), configuring and viewing security policies, and configuring network monitoring behavior.
Linux Kernel BPF¶
Berkeley Packet Filter (BPF) is a Linux kernel bytecode interpreter originally introduced to filter network packets, e.g. tcpdump and socket filters. It has since been extended with additional data structures such as hashtable and arrays as well as additional actions to support packet mangling, forwarding, encapsulation, etc. An in-kernel verifier ensures that BPF programs are safe to run and a JIT compiler converts the bytecode to CPU architecture specific instructions for native execution efficiency. BPF programs can be run at various hooking points in the kernel such as for incoming packets, outgoing packets, system calls, kprobes, etc.
BPF continues to evolve and gain additional capabilities with each new Linux release. Cilium leverages BPF to perform core datapath filtering, mangling, monitoring and redirection, and requires BPF capabilities that are in any Linux kernel version 4.8.0 or newer. On the basis that 4.8.x is already declared end of life and 4.9.x has been nominated as a stable release we recommend to run at least kernel 4.9.17 (the latest current stable Linux kernel as of this writing is 4.10.x).
Cilium is capable of probing the Linux kernel for available features and will automatically make use of more recent features as they are detected.
Linux distros that focus on being a container runtime (e.g., CoreOS, Fedora Atomic) typically already ship kernels that are newer than 4.8, but even recent versions of general purpose operating systems such as Ubuntu 16.10 ship fairly recent kernels. Some Linux distributions still ship older kernels but many of them allow installing recent kernels from separate kernel package repositories.
For more detail on kernel versions, see: Linux Kernel.
Key-Value Store¶
The Key-Value (KV) Store is used for the following state:
- Policy Identities: list of labels <=> policy identity identifier
- Global Services: global service id to VIP association (optional)
- Encapsulation VTEP mapping (optional)
To simplify things in a larger deployment, the key-value store can be the same one used by the container orchestrator (e.g., Kubernetes using etcd).
Cilium Operator¶
The Cilium Operator is responsible for managing duties in the cluster which should logically be handled once for the entire cluster, rather than once for each node in the cluster. Its design helps with scale limitations in large kubernetes clusters (>1000 nodes). The responsibilities of Cilium operator include:
- Synchronizing kubernetes services with etcd for Cluster Mesh
- Synchronizing node resources with etcd
- Ensuring that DNS pods are managed by Cilium
- Garbage-collection of Cilium Endpoints resources
Assurances¶
If Cilium loses connectivity with the KV-Store, it guarantees that:
- Normal networking operations will continue;
- If policy enforcement is enabled, the existing Endpoint will still have their policy enforced but you will lose the ability to add additional containers that belong to security identities which are unknown on the node;
- If services are enabled, you will lose the ability to add additional services / loadbalancers;
- When the connectivity is restored to the KV-Store, Cilium can take up to 5 minutes to re-sync the out-of-sync state with the KV-Store.
Cilium will keep running even if it is out-of-sync with the KV-Store.
If Cilium crashes / or the DaemonSet is accidentally deleted, the following are guaranteed:
- When running Cilium as a DaemonSet / container, with the specification files provided in the documentation Installation with external etcd, the endpoints / containers which are already running will not lose any connectivity, and they will keep running with the policy loaded before Cilium stopped unexpectedly.
- When running Cilium in a different way, just make sure the bpf fs is mounted Mounted BPF filesystem.
Terminology¶
Labels¶
Labels are a generic, flexible and highly scalable way of addressing a large set of resources as they allow for arbitrary grouping and creation of sets. Whenever something needs to be described, addressed or selected, it is done based on labels:
- Endpoint are assigned labels as derived from the container runtime, orchestration system, or other sources.
- Network Policy select pairs of Endpoint which are allowed to communicate based on labels. The policies themselves are identified by labels as well.
What is a Label?¶
A label is a pair of strings consisting of a key and value. A label can
be formatted as a single string with the format key=value. The key portion
is mandatory and must be unique. This is typically achieved by using the
reverse domain name notion, e.g. io.cilium.mykey=myvalue. The value portion
is optional and can be omitted, e.g. io.cilium.mykey.
Key names should typically consist of the character set [a-z0-9-.].
When using labels to select resources, both the key and the value must match,
e.g. when a policy should be applied to all endpoints with the label
my.corp.foo then the label my.corp.foo=bar will not match the
selector.
Label Source¶
A label can be derived from various sources. For example, an endpoint will derive the labels associated to the container by the local container runtime as well as the labels associated with the pod as provided by Kubernetes. As these two label namespaces are not aware of each other, this may result in conflicting label keys.
To resolve this potential conflict, Cilium prefixes all label keys with
source: to indicate the source of the label when importing labels, e.g.
k8s:role=frontend, container:user=joe, k8s:role=backend. This means
that when you run a Docker container using docker run [...] -l foo=bar, the
label container:foo=bar will appear on the Cilium endpoint representing the
container. Similarly, a Kubernetes pod started with the label foo: bar
will be represented with a Cilium endpoint associated with the label
k8s:foo=bar. A unique name is allocated for each potential source. The
following label sources are currently supported:
container:for labels derived from the local container runtimek8s:for labels derived from Kubernetesmesos:for labels derived from Mesosreserved:for special reserved labels, see Special Identities.unspec:for labels with unspecified source
When using labels to identify other resources, the source can be included to
limit matching of labels to a particular type. If no source is provided, the
label source defaults to any: which will match all labels regardless of
their source. If a source is provided, the source of the selecting and matching
labels need to match.
Endpoint¶
Cilium makes application containers available on the network by assigning them
IP addresses. Multiple application containers can share the same IP address; a
typical example for this model is a Kubernetes Pod. All application containers
which share a common address are grouped together in what Cilium refers to as
an endpoint.
Allocating individual IP addresses enables the use of the entire Layer 4 port
range by each endpoint. This essentially allows multiple application containers
running on the same cluster node to all bind to well known ports such as 80
without causing any conflicts.
The default behavior of Cilium is to assign both an IPv6 and IPv4 address to
every endpoint. However, this behavior can be configured to only allocate an
IPv6 address with the --enable-ipv4=false option. If both an IPv6 and IPv4
address are assigned, either address can be used to reach the endpoint. The
same behavior will apply with regard to policy rules, load-balancing, etc. See
Address Management for more details.
Identification¶
For identification purposes, Cilium assigns an internal endpoint id to all endpoints on a cluster node. The endpoint id is unique within the context of an individual cluster node.
Endpoint Metadata¶
An endpoint automatically derives metadata from the application containers associated with the endpoint. The metadata can then be used to identify the endpoint for security/policy, load-balancing and routing purposes.
The source of the metadata will depend on the orchestration system and container runtime in use. The following metadata retrieval mechanisms are currently supported:
| System | Description |
|---|---|
| Kubernetes | Pod labels (via k8s API) |
| Mesos | Labels (via CNI) |
| containerd (Docker) | Container labels (via Docker API) |
Metadata is attached to endpoints in the form of Labels.
The following example launches a container with the label app=benchmark
which is then associated with the endpoint. The label is prefixed with
container: to indicate that the label was derived from the container
runtime.
$ docker run --net cilium -d -l app=benchmark tgraf/netperf
aaff7190f47d071325e7af06577f672beff64ccc91d2b53c42262635c063cf1c
$ cilium endpoint list
ENDPOINT POLICY IDENTITY LABELS (source:key[=value]) IPv6 IPv4 STATUS
ENFORCEMENT
62006 Disabled 257 container:app=benchmark f00d::a00:20f:0:f236 10.15.116.202 ready
An endpoint can have metadata associated from multiple sources. A typical
example is a Kubernetes cluster which uses containerd as the container runtime.
Endpoints will derive Kubernetes pod labels (prefixed with the k8s: source
prefix) and containerd labels (prefixed with container: source prefix).
Identity¶
All Endpoint are assigned an identity. The identity is what is used to enforce basic connectivity between endpoints. In traditional networking terminology, this would be equivalent to Layer 3 enforcement.
An identity is identified by Labels and is given a cluster wide unique identifier. The endpoint is assigned the identity which matches the endpoint’s Security Relevant Labels, i.e. all endpoints which share the same set of Security Relevant Labels will share the same identity. This concept allows to scale policy enforcement to a massive number of endpoints as many individual endpoints will typically share the same set of security Labels as applications are scaled.
What is an Identity?¶
The identity of an endpoint is derived based on the Labels associated with the pod or container which are derived to the endpoint. When a pod or container is started, Cilium will create an endpoint based on the event received by the container runtime to represent the pod or container on the network. As a next step, Cilium will resolve the identity of the endpoint created. Whenever the Labels of the pod or container change, the identity is reconfirmed and automatically modified as required.
Security Relevant Labels¶
Not all Labels associated with a container or pod are meaningful when
deriving the Identity. Labels may be used to store metadata such as the
timestamp when a container was launched. Cilium requires to know which labels
are meaningful and are subject to being considered when deriving the identity.
For this purpose, the user is required to specify a list of string prefixes of
meaningful labels. The standard behavior is to include all labels which start
with the prefix id., e.g. id.service1, id.service2,
id.groupA.service44. The list of meaningful label prefixes can be specified
when starting the agent.
Special Identities¶
All endpoints which are managed by Cilium will be assigned an identity. In
order to allow communication to network endpoints which are not managed by
Cilium, special identities exist to represent those. Special reserved
identities are prefixed with the string reserved:.
| Identity | Description |
|---|---|
| reserved:unknown | The identity could not be derived. |
| reserved:host | The collection of all cluster hosts. Any traffic that originates from or is designated to one of the IPs of any host in the cluster is assigned the reserved:host identity. |
| reserved:world | Any network endpoint outside of the cluster |
| reserved:health | This is health checking traffic generated by Cilium agents. |
| reserved:init | An endpoint for which the identity has not yet been resolved is assigned the init identity. This represents the phase of an endpoint in which some of the metadata required to derive the security identity is still missing. This is typically the case in the bootstrapping phase. The init identity is only allocated if the labels of the endpoint are not known at creation time. This can be the case for the Docker plugin. |
| reserved:unmanaged | An endpoint that is not managed by Cilium, e.g. a Kubernetes pod that was launched before Cilium was installed. |
Well-known Identities¶
The following is a list of well-known identities which Cilium is aware of automatically and will hand out a security identity without requiring to contact any external dependencies such as the kvstore. The purpose of this is to allow bootstrapping Cilium and enable network connectivity with policy enforcement in the cluster for essential services without depending on any dependencies.
| Deployment | Namespace | ServiceAccount | Cluster Name | Numeric ID | Labels |
|---|---|---|---|---|---|
| cilium-etcd-operator | <cilium-namespace> | cilium-etcd-operator | <cilium-cluster> | 107 | name=cilium-etcd-operator, io.cilium/app=etcd-operator |
| etcd-operator | <cilium-namespace> | cilium-etcd-sa | <cilium-cluster> | 100 | io.cilium/app=etcd-operator |
| cilium-etcd | <cilium-namespace> | default | <cilium-cluster> | 101 | app=etcd, etcd_cluster=cilium-etcd, io.cilium/app=etcd-operator |
| kube-dns | kube-system | kube-dns | <cilium-cluster> | 102 | k8s-app=kube-dns |
| kube-dns (EKS) | kube-system | kube-dns | <cilium-cluster> | 103 | k8s-app=kube-dns, eks.amazonaws.com/component=kube-dns |
| core-dns | kube-system | coredns | <cilium-cluster> | 104 | k8s-app=kube-dns |
| core-dns (EKS) | kube-system | coredns | <cilium-cluster> | 106 | k8s-app=kube-dns, eks.amazonaws.com/component=coredns |
| cilium-operator | <cilium-namespace> | cilium-operator | <cilium-cluster> | 105 | name=cilium-operator, io.cilium/app=operator |
Note: if cilium-cluster is not defined with the cluster-name option,
the default value will be set to “default”.
Identity Management in the Cluster¶
Identities are valid in the entire cluster which means that if several pods or containers are started on several cluster nodes, all of them will resolve and share a single identity if they share the identity relevant labels. This requires coordination between cluster nodes.
The operation to resolve an endpoint identity is performed with the help of the distributed key-value store which allows to perform atomic operations in the form generate a new unique identifier if the following value has not been seen before. This allows each cluster node to create the identity relevant subset of labels and then query the key-value store to derive the identity. Depending on whether the set of labels has been queried before, either a new identity will be created, or the identity of the initial query will be returned.
Node¶
Cilium refers to a node as an individual member of a cluster. Each node must be
running the cilium-agent and will operate in a mostly autonomous manner.
Synchronization of state between Cilium agent’s running on different nodes is
kept to a minimum for simplicity and scale. It occurs exclusively via the
Key-Value store or with packet metadata.
Node Address¶
Cilium will automatically detect the node’s IPv4 and IPv6 address. The detected
node address is printed out when the cilium-agent starts:
Local node-name: worker0
Node-IPv6: f00d::ac10:14:0:1
External-Node IPv4: 172.16.0.20
Internal-Node IPv4: 10.200.28.238
Address Management¶
The address management is designed with simplicity and resilience in mind. This is achieved by delegating the address allocation for endpoints to each individual node in the cluster. Each cluster node is assigned a node address allocation prefix out of an overarching cluster address prefix and will allocate IPs for endpoints independently.
This simplifies address handling and allows one to make a fundamental assumption:
- No state needs to be synchronized between cluster nodes to allocate IP addresses and to determine whether an IP address belongs to an endpoint of the cluster and whether that endpoint resides on the local cluster node.
Note
If you are using Kubernetes, the allocation of the node address prefix
can be simply delegated to Kubernetes by specifying
--allocate-node-cidrs flag to kube-controller-manager. Cilium
will automatically use the IPv4 node CIDR allocated by Kubernetes.
The following values are used by default if the cluster prefix is left unspecified. These are meant for testing and need to be adjusted according to the needs of your environment.
| Type | Cluster | Node Prefix |
| IPv4 | 10.0.0.0/8 |
10.X.0.0/16 where X is derived using the
last 8 bits of the first IPv4 address in the list
of global scope addresses on the cluster node. |
| IPv6 | f00d::/48 |
Note: Only 16 bits out of the |
The size of the IPv4 cluster prefix can be changed with the
--ipv4-cluster-cidr-mask-size option. The size of the IPv6 cluster prefix
is currently fixed sized at /48. The node allocation prefixes can be
specified manually with the option --ipv4-range respectively
--ipv6-range.
Multi Host Networking¶
Cilium is in full control over both ends of the connection for connections inside the cluster. It can thus transmit state and security context information between two container hosts by embedding the information in encapsulation headers or even unused bits of the IPv6 packet header. This allows Cilium to transmit the security context of where the packet originates, which allows tracing back which container labels are assigned to the origin container.
Note
As the packet headers contain security sensitive information, it is highly recommended to either encrypt all traffic or run Cilium in a trusted network environment.
Cilium keeps the networking concept as simple as possible. There are two networking models to choose from.
Regardless of the option chosen, the container itself has no awareness of the underlying network it runs on; it only contains a default route which points to the IP address of the cluster node. Given the removal of the routing cache in the Linux kernel, this reduces the amount of state to keep in the per connection flow cache (TCP metrics), which allows to terminate millions of connections in each container.
Overlay Network Mode¶
When no configuration is provided, Cilium automatically runs in this mode.
In this mode, all cluster nodes form a mesh of tunnels using the UDP based
encapsulation protocols VXLAN or Geneve. All container-to-container network
traffic is routed through these tunnels. This mode has several major
advantages:
- Simplicity: The network which connects the cluster nodes does not need to be made aware of the cluster prefix. Cluster nodes can spawn multiple routing or link-layer domains. The topology of the underlying network is irrelevant as long as cluster nodes can reach each other using IP/UDP.
- Auto-configuration: When running together with an orchestration system
such as Kubernetes, the list of all nodes in the cluster including their
associated allocation prefix node is made available to each agent
automatically. This means that if Kubernetes is being run with the
--allocate-node-cidrsoption, Cilium can form an overlay network automatically without any configuration by the user. New nodes joining the cluster will automatically be incorporated into the mesh. - Identity transfer: Encapsulation protocols allow for the carrying of arbitrary metadata along with the network packet. Cilium makes use of this ability to transfer metadata such as the source security identity and load balancing state to perform direct-server-return.
Direct / Native Routing Mode¶
Note
This is an advanced networking mode which requires the underlying
network to be made aware of container IPs. You can enable this mode
by running Cilium with the option --tunnel disabled.
In direct routing mode, Cilium will hand all packets which are not addressed for another local endpoint to the routing subsystem of the Linux kernel. This means that the packet will be routed as if a local process would have emitted the packet. As a result, the network connecting the cluster nodes must be aware that each of the node IP prefixes are reachable by using the node’s primary IP address as an L3 next hop address.
Cilium automatically enables IP forwarding in Linux when direct mode is configured, but it is up to the container cluster administrator to ensure that each routing element in the underlying network has a route that describes each node IP as the IP next hop for the corresponding node prefix.
This is typically achieved using two methods:
- Operation of a routing protocol such as OSPF or BGP via routing daemon such as Zebra, bird, bgpd. The routing protocols will announce the node allocation prefix via the node’s IP to all other nodes.
- Use of the cloud provider’s routing functionality. Refer to the documentation
of your cloud provider for additional details (e.g,. AWS VPC Route Tables
or GCE Routes). These APIs can be used to associate each node prefix with
the appropriate next hop IP each time a container node is added to the
cluster. If you are running Kubernetes with the
--cloud-providerin combination with the--allocate-node-cidrsoption then this is configured automatically for IPv4 prefixes.
Note
Use of direct routing mode with advanced policy use cases such as L7 policies is currently beta. Please provide feedback and file a GitHub issue if you experience any problems.
There are two possible approaches to performing network forwarding for container-to-container traffic:
Cluster Mesh¶
Cluster mesh extends the networking datapath across multiple clusters. It allows endpoints in all connected clusters to communicate while providing full policy enforcement. Load-balancing is available via Kubernetes annotations.
See Setting up Cluster Mesh for instructions on how to set up cluster mesh.
Container Communication with External Hosts¶
Container communication with the outside world has two primary modes:
- Containers exposing API services for consumption by hosts outside of the container cluster.
- Containers making outgoing connections. Examples include connecting to 3rd-party API services like Twilio or Stripe as well as accessing private APIs that are hosted elsewhere in your enterprise datacenter or cloud deployment.
In the Direct / Native Routing Mode mode described before, if container IP addresses are routable outside of the container cluster, communication with external hosts requires little more than enabling L3 forwarding on each of the Linux nodes.
External Network Connectivity¶
If the destination of a packet lies outside of the cluster, Cilium will delegate routing to the routing subsystem of the cluster node to use the default route which is installed on the node of the cluster.
As the IP addresses used for the cluster prefix are typically allocated
from RFC1918 private address blocks and are not publicly routable. Cilium will
automatically masquerade the source IP address of all traffic that is leaving
the cluster. This behavior can be disabled by running cilium-agent with
the option --masquerade=false.
Public Endpoint Exposure¶
In direct routing mode, endpoint IPs can be publicly routable IPs and no additional action needs to be taken.
In overlay mode, endpoints that are accepting inbound connections from cluster external clients likely want to be exposed via some kind of load-balancing layer. Such a load-balancer will have a public external address that is not part of the Cilium network. This can be achieved by having a load-balancer container that both has a public IP on an externally reachable network and a private IP on a Cilium network. However, many container orchestration frameworks, like Kubernetes, have built in abstractions to handle this “ingress” load-balancing capability, which achieve the same effect that Cilium handles forwarding and security only for ‘’internal’’ traffic between different services.
Security¶
Cilium provides security on multiple levels. Each can be used individually or combined together.
- Identity based Connectivity Access Control: Connectivity policies between endpoints (Layer 3),
e.g. any endpoint with label
role=frontendcan connect to any endpoint with labelrole=backend. - Restriction of accessible ports (Layer 4) for both incoming and outgoing
connections, e.g. endpoint with label
role=frontendcan only make outgoing connections on port 443 (https) and endpointrole=backendcan only accept connections on port 443 (https). - Fine grained access control on application protocol level to secure HTTP and
remote procedure call (RPC) protocols, e.g the endpoint with label
role=frontendcan only perform the REST API callGET /userdata/[0-9]+, all other API interactions withrole=backendare restricted.
Currently on the roadmap, to be added soon:
- Authentication: Any endpoint which wants to initiate a connection to an
endpoint with the label
role=backendmust have a particular security certificate to authenticate itself before being able to initiate any connections. See GH issue 502 for additional details. - Encryption: Communication between any endpoint with the label
role=frontendto any endpoint with the labelrole=backendis automatically encrypted with a key that is automatically rotated. See GH issue 504 to track progress on this feature.
Identity based Connectivity Access Control¶
Container management systems such as Kubernetes deploy a networking model which assigns an individual IP address to each pod (group of containers). This ensures simplicity in architecture, avoids unnecessary network address translation (NAT) and provides each individual container with a full range of port numbers to use. The logical consequence of this model is that depending on the size of the cluster and total number of pods, the networking layer has to manage a large number of IP addresses.
Traditionally security enforcement architectures have been based on IP address
filters. Let’s walk through a simple example: If all pods with the label
role=frontend should be allowed to initiate connections to all pods with
the label role=backend then each cluster node which runs at least one pod
with the label role=backend must have a corresponding filter installed
which allows all IP addresses of all role=frontend pods to initiate a
connection to the IP addresses of all local role=backend pods. All other
connection requests should be denied. This could look like this: If the
destination address is 10.1.1.2 then allow the connection only if the source
address is one of the following [10.1.2.2,10.1.2.3,20.4.9.1].
Every time a new pod with the label role=frontend or role=backend is
either started or stopped, the rules on every cluster node which run any such
pods must be updated by either adding or removing the corresponding IP address
from the list of allowed IP addresses. In large distributed applications, this
could imply updating thousands of cluster nodes multiple times per second
depending on the churn rate of deployed pods. Worse, the starting of new
role=frontend pods must be delayed until all servers running
role=backend pods have been updated with the new security rules as
otherwise connection attempts from the new pod could be mistakenly dropped.
This makes it difficult to scale efficiently.
In order to avoid these complications which can limit scalability and
flexibility, Cilium entirely separates security from network addressing.
Instead, security is based on the identity of a pod, which is derived through
labels. This identity can be shared between pods. This means that when the
first role=frontend pod is started, Cilium assigns an identity to that pod
which is then allowed to initiate connections to the identity of the
role=backend pod. The subsequent start of additional role=frontend pods
only requires to resolve this identity via a key-value store, no action has to
be performed on any of the cluster nodes hosting role=backend pods. The
starting of a new pod must only be delayed until the identity of the pod has
been resolved which is a much simpler operation than updating the security
rules on all other cluster nodes.
Policy Enforcement¶
All security policies are described assuming stateful policy enforcement for
session based protocols. This means that the intent of the policy is to
describe allowed direction of connection establishment. If the policy allows
A => B then reply packets from B to A are automatically allowed as
well. However, B is not automatically allowed to initiate connections to
A. If that outcome is desired, then both directions must be explicitly
allowed.
Security policies may be enforced at ingress or egress. For ingress, this means that each cluster node verifies all incoming packets and determines whether the packet is allowed to be transmitted to the intended endpoint. Correspondingly, for egress each cluster node verifies outgoing packets and determines whether the packet is allowed to be transmitted to its intended destination.
In order to enforce identity based security in a multi host cluster, the identity of the transmitting endpoint is embedded into every network packet that is transmitted in between cluster nodes. The receiving cluster node can then extract the identity and verify whether a particular identity is allowed to communicate with any of the local endpoints.
Default Security Policy¶
If no policy is loaded, the default behavior is to allow all communication unless policy enforcement has been explicitly enabled. As soon as the first policy rule is loaded, policy enforcement is enabled automatically and any communication must then be white listed or the relevant packets will be dropped.
Similarly, if an endpoint is not subject to an L4 policy, communication from and to all ports is permitted. Associating at least one L4 policy to an endpoint will block all connectivity to ports unless explicitly allowed.
Orchestration System Specifics¶
Kubernetes¶
Cilium regards each deployed Pod as an endpoint with regards to networking and
security policy enforcement. Labels associated with pods can be used to define
the identity of the endpoint.
When two pods communicate via a service construct, then the labels of the origin pod apply to determine the identity.
Architecture¶
This document describes the Cilium architecture. It focuses on documenting the BPF datapath hooks to implement the Cilium datapath, how the Cilium datapath integrates with the container orchestration layer, and the objects shared between the layers e.g. the BPF datapath and Cilium agent.
Datapath¶
The Linux kernel supports a set of BPF hooks in the networking stack that can be used to run BPF programs. The Cilium datapath uses these hooks to load BPF programs that when used together create higher level networking constructs.
The following is a list of the hooks used by Cilium and a brief description. For a more thorough documentation on specifics of each hook see BPF and XDP Reference Guide.
XDP: The XDP BPF hook is at the earliest point possible in the networking driver and triggers a run of the BPF program upon packet reception. This achieves the best possible packet processing performance since the program runs directly on the packet data before any other processing can happen. This hook is ideal for running filtering programs that drop malicious or unexpected traffic, and other common DDOS protection mechanisms.
Traffic Control Ingress/Egress: BPF programs attached to the traffic control (tc) ingress hook are attached to a networking interface, same as XDP, but will run after the networking stack has done initial processing of the packet. The hook is run before the L3 layer of the stack but has access to most of the metadata associated with a packet. This is ideal for doing local node processing, such as applying L3/L4 endpoint policy and redirecting traffic to endpoints. For networking facing devices the tc ingress hook can be coupled with above XDP hook. When this is done it is reasonable to assume that the majority of the traffic at this point is legitimate and destined for the host.
Containers typically use a virtual device called a veth pair which acts as a virtual wire connecting the container to the host. By attaching to the TC ingress hook of the host side of this veth pair Cilium can monitor and enforce policy on all traffic exiting a container. By attaching a BPF program to the veth pair associated with each container and routing all network traffic to the host side virtual devices with another BPF program attached to the tc ingress hook as well Cilium can monitor and enforce policy on all traffic entering or exiting the node.
Depending on the use case, containers may also be connected through ipvlan devices instead of a veth pair. In this mode, the physical device in the host is the ipvlan master where virtual ipvlan devices in slave mode are set up inside the container. One of the benefits of ipvlan over a veth pair is that the stack requires less resources to push the packet into the ipvlan slave device of the other network namespace and therefore may achieve better latency results. This option can be used for unprivileged containers. The BPF programs for tc are then attached to the tc egress hook on the ipvlan slave device inside the container’s network namespace in order to have Cilium apply L3/L4 endpoint policy, for example, combined with another BPF program running on the tc ingress hook of the ipvlan master such that also incoming traffic on the node can be enforced.
Socket operations: The socket operations hook is attached to a specific cgroup and runs on TCP events. Cilium attaches a BPF socket operations program to the root cgroup and uses this to monitor for TCP state transitions, specifically for ESTABLISHED state transitions. When a socket transitions into ESTABLISHED state if the TCP socket has a node local peer (possibly a local proxy) a socket send/recv program is attached.
Socket send/recv: The socket send/recv hook runs on every send operation performed by a TCP socket. At this point the hook can inspect the message and either drop the message, send the message to the TCP layer, or redirect the message to another socket. Cilium uses this to accelerate the datapath redirects as described below.
Combining the above hooks with a virtual interfaces (cilium_host, cilium_net), an optional overlay interface (cilium_vxlan) and a userspace proxy (Envoy) Cilium creates the following networking objects.
- Prefilter: The prefilter object runs an XDP program and provides a set of prefilter rules used to filter traffic from the network for best performance. Specifically, a set of CIDR maps supplied by the Cilium agent are used to do a lookup and the packet is either dropped, for example when the destination is not a valid endpoint, or allowed to be processed by the stack. This can be easily extended as needed to build in new prefilter criteria/capabilities.
- Endpoint Policy: The endpoint policy object implements the Cilium endpoint enforcement. Using a map to lookup a packets associated identity and policy this layer scales well to lots of endpoints. Depending on the policy this layer may drop the packet, forward to a local endpoint, forward to the service object or forward to the L7 Policy object for further L7 rules. This is the primary object in the Cilium datapath responsible for mapping packets to identities and enforcing L3 and L4 policies.
- Service: The Service object performs a map lookup on the destination IP and optionally destination port for every packet received by the object. If a matching entry is found, the packet will be forwarded to one of the configured L3/L4 endpoints. The Service block can be used to implement a standalone load balancer on any interface using the TC ingress hook or may be integrated in the endpoint policy object.
- Socket Layer Enforcement: Socket layer enforcement use two hooks the socket operations hook and the socket send/recv hook to monitor and attach to all TCP sockets associated with Cilium managed endpoints, including any L7 proxies. The socket operations hook will identify candidate sockets for accelerating. These include all local node connections (endpoint to endpoint) and any connection to a Cilium proxy. These identified connections will then have all messages handled by the socket send/recv hook and will be accelerated using sockmap fast redirects. The fast redirect ensures all policies implemented in Cilium are valid for the associated socket/endpoint mapping and assuming they are sends the message directly to the peer socket. This is allowed because the sockmap send/recv hooks ensures the message will not need to be processed by any of the objects above.
- L7 Policy: The L7 Policy object redirect proxy traffic to a Cilium userspace proxy instance. Cilium uses an Envoy instance as its userspace proxy. Envoy will then either forward the traffic or generate appropriate reject messages based on the configured L7 policy.
These components are connected to create the flexible and efficient datapath used by Cilium. Below we show the following possible flows connecting endpoints on a single node, ingress to an endpoint, and endpoint to egress networking device. In each case there is an additional diagram showing the TCP accelerated path available when socket layer enforcement is enabled.
Endpoint to Endpoint¶
First we show the local endpoint to endpoint flow with optional L7 Policy on egress and ingress. Followed by the same endpoint to endpoint flow with socket layer enforcement enabled. With socket layer enforcement enabled for TCP traffic the handshake initiating the connection will traverse the endpoint policy object until TCP state is ESTABLISHED. Then after the connection is ESTABLISHED only the L7 Policy object is still required.
Egress from Endpoint¶
Next we show local endpoint to egress with optional overlay network. In the optional overlay network traffic is forwarded out the Linux network interface corresponding to the overlay. In the default case the overlay interface is named cilium_vxlan. Similar to above, when socket layer enforcement is enabled and a L7 proxy is in use we can avoid running the endpoint policy block between the endpoint and the L7 Policy for TCP traffic.
Ingress to Endpoint¶
Finally we show ingress to local endpoint also with optional overlay network. Similar to above socket layer enforcement can be used to avoid a set of policy traversals between the proxy and the endpoint socket.
veth-based versus ipvlan-based datapath¶
Note
The ipvlan-based datapath is currently only in technology preview and to be used for experimentation purposes. This restriction will be lifted in future Cilium releases.
By default Cilium CNI operates in veth-based datapath mode which allows for more flexibility in that all BPF programs are managed by Cilium out of the host network namespace such that containers can be granted privileges for their namespaces like CAP_NET_ADMIN without affecting security since BPF enforcement points in the host are unreachable for the container. Given BPF programs are attached from the host’s network namespace, BPF also has the ability to take over and efficiently manage most of the forwarding logic between local containers and host since there always is a networking device reachable. However, this also comes at a latency cost as in veth-based mode the network stack internally needs to be re-traversed when handing the packet from one veth device to its peer device in the other network namespace. This egress-to-ingress switch needs to be done twice when communicating between local Cilium endpoints, and once for packet that are arriving or sent out of the host.
For a more latency optimized datapath, Cilium CNI also supports ipvlan L3/L3S mode with a number of restrictions. In order to support older kernel’s without ipvlan’s hairpin mode, Cilium attaches BPF programs at the ipvlan slave device inside the container’s network namespace on the tc egress layer, which means that this datapath mode can only be used for containers which are not running with CAP_NET_ADMIN and CAP_NET_RAW privileges! ipvlan uses an internal forwarding logic for direct slave-to-slave or slave-to-master redirection and therefore forwarding to devices is not performed from the BPF program itself. The network namespace switching is more efficient in ipvlan mode since the stack does not need to be re-traversed as in veth-based datapath case for external packets. The host-to-container network namespace switch happens directly at L3 layer without having to queue and reschedule the packet for later ingress processing. In case of communication among local endpoints, the egress-to-ingress switch is performed once instead of having to perform it twice.
For Cilium in ipvlan mode there are a number of additional restrictions in the current implementation which are to be addressed in upcoming work: NAT64 cannot be enabled at this point as well as L7 policy enforcement via proxy. Service load-balancing to local endpoints is currently not enabled as well as container to host-local communication. If one of these features are needed, then the default veth-based datapath mode is recommended instead.
The ipvlan mode in Cilium’s CNI can be enabled by running the Cilium daemon
with e.g. --datapath-mode=ipvlan --ipvlan-master-device=bond0 where the
latter typically specifies the physical networking device which then also acts
as the ipvlan master device. Note that in case ipvlan datapath mode is deployed
in L3S mode with Kubernetes, make sure to have a stable kernel running with the
following ipvlan fix included: d5256083f62e.
This completes the datapath overview. More BPF specifics can be found in the BPF and XDP Reference Guide. Additional details on how to extend the L7 Policy exist in the Envoy section.
Scale¶
BPF Map Limitations¶
All BPF maps are created with upper capacity limits. Insertion beyond the limit will fail and thus limits the scalability of the datapath. The following table shows the default values of the maps. Each limit can be bumped in the source code. Configuration options will be added on request if demand arises.
| Map Name | Scope | Default Limit | Scale Implications |
|---|---|---|---|
| Connection Tracking | node or endpoint | 1M TCP/256K UDP | Max 1M concurrent TCP connections, max 256K expected UDP answers |
| Endpoints | node | 64k | Max 64k local endpoints + host IPs per node |
| IP cache | node | 512K | Max 256K endpoints (IPv4+IPv6), max 512k endpoints (IPv4 or IPv6) across all clusters |
| Load Balancer | node | 64k | Max 64k cumulative backends across all services across all clusters [*] |
| Policy | endpoint | 16k | Max 16k allowed identity + port + protocol pairs for specific endpoint |
| Proxy Map | node | 512k | Max 512k concurrent redirected TCP connections to proxy |
| Tunnel | node | 64k | Max 32k nodes (IPv4+IPv6) or 64k nodes (IPv4 or IPv6) across all clusters |
[*] Due to a limitation in the load-balancing implementation, constant churn in the load balancing table by scaling the number of service backends up and down can reduce the maximum number of supported service backends further. If in doubt, increase the limit to 512k.
Kubernetes Integration¶
The following diagram shows the integration of iptables rules as installed by kube-proxy and the iptables rules as installed by Cilium.
Getting Help¶
Cilium is a project with a growing community. There are numerous ways to get help with Cilium if needed:
FAQ¶
Cilium Frequently Asked Questions (FAQ): Cilium uses GitHub tags to maintain a list of questions asked by users. We suggest checking to see if your question is already answered.
Slack¶
Chat: The best way to get immediate help if you get stuck is to ask in one of the Cilium Slack channels.
GitHub¶
Bug Tracker: All the issues are addressed in the GitHub issue tracker. If you want to report a bug or a new feature please file the issue according to the GitHub template.
Contributing: If you want to contribute, reading the Developer / Contributor Guide should help you.
Security Bugs¶
Security: We strongly encourage you to report security vulnerabilities to our private security mailing list: security@cilium.io - first, before disclosing them in any public forums.
This is a private mailing list where only members of the Cilium internal security team are subscribed to, and is treated as top priority.
Kubernetes¶
Cilium provides seamless integration into Kubernetes. The following guidance may help you to navigate this documentation section:
- If you are looking for a simple and safe playground to experiment with Cilium and Kubernetes Getting Started Using Minikube.
- If you want to learn more about Cilium on Kubernetes first: Introduction.
- If you want to run Cilium on your kops cluster: Installation using Kops.
The following sections describe the Kubernetes integration in detail:
Introduction¶
What does Cilium provide in your Kubernetes Cluster?¶
The following functionality is provided as your run Cilium in your Kubernetes cluster:
CNIplugin support to provide pod_connectivity with Multi Host Networking.- Identity based implementation of the NetworkPolicy resource to isolate
podtopodconnectivity on Layer 3 and 4. - An extension to NetworkPolicy in the form of a
CustomResourceDefinitionwhich extends policy control to add:- Layer 7 policy enforcement on ingress and egress for the following
application protocols:
- HTTP
- Kafka
- Egress support for CIDRs to secure access to external services
- Enforcement to external headless services to automatically restrict to the set of Kubernetes endpoints configured for a service.
- Layer 7 policy enforcement on ingress and egress for the following
application protocols:
- ClusterIP implementation to provide distributed load-balancing for pod to pod traffic.
- Fully compatible with existing kube-proxy model
Pod-to-Pod Connectivity¶
In Kubernetes, containers are deployed within units referred to as Pod, which
include one or more containers reachable via a single IP address. With Cilium,
each Pod gets an IP address from the node prefix of the Linux node running the
Pod. See Address Management for additional details. In the absence of any
network security policies, all Pods can reach each other.
Pod IP addresses are typically local to the Kubernetes cluster. If pods need to reach services outside the cluster as a client, the network traffic is automatically masqueraded as it leaves the node. You can find additional information in the section External Network Connectivity.
Service Load-balancing¶
Kubernetes has developed the Services abstraction which provides the user the ability to load balance network traffic to different pods. This abstraction allows the pods reaching out to other pods by a single IP address, a virtual IP address, without knowing all the pods that are running that particular service.
Without Cilium, kube-proxy is installed on every node, watches for endpoints and services addition and removal on the kube-master which allows it to to apply the necessary enforcement on iptables. Thus, the received and sent traffic from and to the pods are properly routed to the node and port serving for that service. For more information you can check out the kubernetes user guide for Services.
When implementing ClusterIP, Cilium acts on the same principles as kube-proxy, it watches for services addition or removal, but instead of doing the enforcement on the iptables, it updates BPF map entries on each node. For more information, see the Pull Request.
Further Reading¶
The Kubernetes documentation contains more background on the Kubernetes Networking Model and Kubernetes Network Plugins .
Concepts¶
Deployment¶
The configuration of a standard Cilium Kubernetes deployment consists of several Kubernetes resources:
- A
DaemonSetresource: describes the Cilium pod that is deployed to each Kubernetes node. This pod runs the cilium-agent and associated daemons. The configuration of this DaemonSet includes the image tag indicating the exact version of the Cilium docker container (e.g., v1.0.0) and command-line options passed to the cilium-agent. - A
ConfigMapresource: describes common configuration values that are passed to the cilium-agent, such as the kvstore endpoint and credentials, enabling/disabling debug mode, etc. ServiceAccount,ClusterRole, andClusterRoleBindingsresources: the identity and permissions used by cilium-agent to access the Kubernetes API server when Kubernetes RBAC is enabled.- A
Secretresource: describes the credentials use access the etcd kvstore, if required.
Networking For Existing Pods¶
In case pods were already running before the Cilium DaemonSet was deployed,
these pods will still be connected using the previous networking plugin
according to the CNI configuration. A typical example for this is the
kube-dns service which runs in the kube-system namespace by default.
A simple way to change networking for such existing pods is to rely on the fact that Kubernetes automatically restarts pods in a Deployment if they are deleted, so we can simply delete the original kube-dns pod and the replacement pod started immediately after will have networking managed by Cilium. In a production deployment, this step could be performed as a rolling update of kube-dns pods to avoid downtime of the DNS service.
$ kubectl --namespace kube-system delete pods -l k8s-app=kube-dns
pod "kube-dns-268032401-t57r2" deleted
Running kubectl get pods will show you that Kubernetes started a new set of
kube-dns pods while at the same time terminating the old pods:
$ kubectl --namespace kube-system get pods
NAME READY STATUS RESTARTS AGE
cilium-5074s 1/1 Running 0 58m
kube-addon-manager-minikube 1/1 Running 0 59m
kube-dns-268032401-j0vml 3/3 Running 0 9s
kube-dns-268032401-t57r2 3/3 Terminating 0 57m
Default Ingress Allow from Local Host¶
Kubernetes has functionality to indicate to users the current health of their
applications via Liveness Probes and Readiness Probes.
In order for kubelet to run these health checks for each pod, by default,
Cilium will always allow all ingress traffic from the local host to each pod.
Requirements¶
Kubernetes Version¶
The following Kubernetes versions have been tested in the continuous integration system for this version of Cilium:
- 1.10
- 1.11
- 1.12
- 1.13
- 1.14
- 1.15
System Requirements¶
Cilium requires a Linux kernel >= 4.9. See System Requirements for the full details on all systems requirements.
Enable CNI in Kubernetes¶
CNI - Container Network Interface is the plugin layer used by Kubernetes to
delegate networking configuration. CNI must be enabled in your Kubernetes
cluster in order to install Cilium. This is done by passing
--network-plugin=cni to kubelet on all nodes. For more information, see
the Kubernets CNI network-plugins documentation.
Mounted BPF filesystem¶
This step is required for production environments but optional for testing
and development. It allows the cilium-agent to pin BPF resources to a
persistent filesystem and make them persistent across restarts of the agent.
If the BPF filesystem is not mounted in the host filesystem, Cilium will
automatically mount the filesystem but it will be unmounted and re-mounted when
the Cilium pod is restarted. This in turn will cause BPF resources to be
re-created which will cause network connectivity to be disrupted. Mounting the
BPF filesystem in the host mount namespace will ensure that the agent can be
restarted without affecting connectivity of any pods.
In order to mount the BPF filesystem, the following command must be run in the host mount namespace. The command must only be run once during the boot process of the machine.
mount bpffs /sys/fs/bpf -t bpf
A portable way to achieve this with persistence is to add the following line to
/etc/fstab and then run mount /sys/fs/bpf. This will cause the
filesystem to be automatically mounted when the node boots.
bpffs /sys/fs/bpf bpf defaults 0 0
If you are using systemd to manage the kubelet, see the section Mounting BPFFS with systemd.
kube-dns¶
The Standard Installation relies on the etcd-operator to manage an
etcd cluster. In order for the etcd cluster to be available, the Cilium pod is
being run with dnsPolicy: ClusterFirstWithHostNet in order for Cilium to be
able to look up Kubernetes service names via DNS. This creates a dependency on
kube-dns. If you would like to avoid running kube-dns, choose a different
installation method and remove the dnsPolicy field from the DaemonSet.
Enable automatic node CIDR allocation (Recommended)¶
Kubernetes has the capability to automatically allocate and assign a per node IP
allocation CIDR. Cilium automatically uses this feature if enabled. This is the
easiest method to handle IP allocation in a Kubernetes cluster. To enable this
feature, simply add the following flag when starting
kube-controller-manager:
--allocate-node-cidrs
This option is not required but highly recommended.
Configuration¶
ConfigMap Options¶
In the ConfigMap there are several options that can be configured according
to your preferences:
debug- Sets to run Cilium in full debug mode, which enables verbose logging and configures BPF programs to emit more visibility events into the output ofcilium monitor.enable-ipv4- Enable IPv4 addressing supportenable-ipv6- Enable IPv6 addressing supportclean-cilium-bpf-state- Removes all BPF state from the filesystem on startup. Endpoints will be restored with the same IP addresses, but ongoing connections may be briefly disrupted and loadbalancing decisions will be lost, so active connections via the loadbalancer will break. All BPF state will be reconstructed from their original sources (for example, from kubernetes or the kvstore). This may be used to mitigate serious issues regarding BPF maps. This option should be turned off again after restarting the daemon.clean-cilium-state- Removes all Cilium state, including unrecoverable information such as all endpoint state, as well as recoverable state such as BPF state pinned to the filesystem, CNI configuration files, library code, links, routes, and other information. This operation is irreversible. Existing endpoints currently managed by Cilium may continue to operate as before, but Cilium will no longer manage them and they may stop working without warning. After using this operation, endpoints must be deleted and reconnected to allow the new instance of Cilium to manage them.monitor-aggregation- This option enables coalescing of tracing events incilium monitorto only include periodic updates from active flows, or any packets that involve an L4 connection state change. Valid options arenone,low,medium,maximum.preallocate-bpf-maps- Pre-allocation of map entries allows per-packet latency to be reduced, at the expense of up-front memory allocation for the entries in the maps. Set totrueto optimize for latency. If this value is modified, then during the next Cilium startup connectivity may be temporarily disrupted for endpoints with active connections.
Any changes that you perform in the Cilium ConfigMap and in
cilium-etcd-secrets Secret will require you to restart any existing
Cilium pods in order for them to pick the latest configuration.
The following ConfigMap is an example where the etcd cluster is running in 2
nodes, node-1 and node-2 with TLS, and client to server authentication
enabled.
apiVersion: v1
kind: ConfigMap
metadata:
name: cilium-config
namespace: kube-system
data:
endpoints:
- https://node-1:31079
- https://node-2:31079
#
# In case you want to use TLS in etcd, uncomment the 'ca-file' line
# and create a kubernetes secret by following the tutorial in
# https://cilium.link/etcd-config
ca-file: '/var/lib/etcd-secrets/etcd-client-ca.crt'
#
# In case you want client to server authentication, uncomment the following
# lines and create a kubernetes secret by following the tutorial in
# https://cilium.link/etcd-config
key-file: '/var/lib/etcd-secrets/etcd-client.key'
cert-file: '/var/lib/etcd-secrets/etcd-client.crt'
# If you want to run cilium in debug mode change this value to true
debug: "false"
enable-ipv4: "true"
# If you want to clean cilium state; change this value to true
clean-cilium-state: "false"
CNI¶
CNI - Container Network Interface is the plugin layer used by Kubernetes to
delegate networking configuration. You can find additional information on the
CNI project website.
Note
Kubernetes `` >= 1.3.5`` requires the loopback CNI plugin to be
installed on all worker nodes. The binary is typically provided by
most Kubernetes distributions. See section Manually installing CNI for
instructions on how to install CNI in case the loopback binary
is not already installed on your worker nodes.
CNI configuration is automatically being taken care of when deploying Cilium
via the provided DaemonSet. The script cni-install.sh is automatically run
via the postStart mechanism when the cilium pod is started.
Note
In order for the the cni-install.sh script to work properly, the
kubelet task must either be running on the host filesystem of the
worker node, or the /etc/cni/net.d and /opt/cni/bin
directories must be mounted into the container where kubelet is
running. This can be achieved with Volumes mounts.
The CNI auto installation is performed as follows:
- The
/etc/cni/net.dand/opt/cni/bindirectories are mounted from the host filesystem into the pod where Cilium is running. - The file
/etc/cni/net.d/05-cilium.confis written in case it does not exist yet. - The binary
cilium-cniis installed to/opt/cni/bin. Any existing binary with the namecilium-cniis overwritten.
Manually installing CNI¶
This step is typically already included in all Kubernetes distributions or Kubernetes installers but can be performed manually:
sudo mkdir -p /opt/cni
wget https://storage.googleapis.com/kubernetes-release/network-plugins/cni-0799f5732f2a11b329d9e3d51b9c8f2e3759f2ff.tar.gz
sudo tar -xvf cni-0799f5732f2a11b329d9e3d51b9c8f2e3759f2ff.tar.gz -C /opt/cni
rm cni-0799f5732f2a11b329d9e3d51b9c8f2e3759f2ff.tar.gz
Adjusting CNI configuration¶
The CNI installation can be configured with environment variables. These
environment variables can be specified in the DaemonSet file like this:
env:
- name: "CNI_CONF_NAME"
value: "05-cilium.conf"
The following variables are supported:
| Option | Description | Default |
| HOST_PREFIX | Path prefix of all host mounts | /host |
| CNI_DIR | Path to mounted CNI directory | ${HOST_PREFIX}/opt/cni |
| CNI_CONF_NAME | Name of configuration file | 05-cilium.conf |
If you want to further adjust the CNI configuration you may do so by creating
the CNI configuration /etc/cni/net.d/05-cilium.conf manually:
sudo mkdir -p /etc/cni/net.d
sudo sh -c 'echo "{
"name": "cilium",
"type": "cilium-cni"
}
" > /etc/cni/net.d/05-cilium.conf'
Cilium will use any existing /etc/cni/net.d/05-cilium.conf file if it
already exists on a worker node and only creates it if it does not exist yet.
Enabling hostPort Support via CNI configuration¶
Some users may want to enable hostPort. Currently, cilium does not natively
support hostPort. However, users can utilize hostPort via a CNI plugin
chain, by putting it in their cni-conf-dir (default /etc/cni/net.d), e.g.:
{
"cniVersion": "0.3.1",
"name": "cilium-portmap",
"plugins": [
{
"type": "cilium-cni"
},
{
"type": "portmap",
"capabilities": { "portMappings": true }
}
]
}
For more information about hostPort, check the Kubernetes hostPort-CNI plugin documentation.
CRD Validation¶
Custom Resource Validation was introduced in Kubernetes since version 1.8.0.
This is still considered an alpha feature in Kubernetes 1.8.0 and beta in
Kubernetes 1.9.0.
Since Cilium v1.0.0-rc3, Cilium will create, or update in case it exists,
the Cilium Network Policy (CNP) Resource Definition with the embedded
validation schema. This allows the validation of CiliumNetworkPolicy to be done
on the kube-apiserver when the policy is imported with an ability to provide
direct feedback when importing the resource.
To enable this feature, the flag --feature-gates=CustomResourceValidation=true
must be set when starting kube-apiserver. Cilium itself will automatically make
use of this feature and no additional flag is required.
Note
In case there is an invalid CNP before updating to Cilium
v1.0.0-rc3, which contains the validator, the kube-apiserver
validator will prevent Cilium from updating that invalid CNP with
Cilium node status. By checking Cilium logs for unable to update
CNP, retrying..., it is possible to determine which Cilium Network
Policies are considered invalid after updating to Cilium
v1.0.0-rc3.
To verify that the CNP resource definition contains the validation schema, run the following command:
kubectl get crd ciliumnetworkpolicies.cilium.io -o json
kubectl get crd ciliumnetworkpolicies.cilium.io -o json | grep -A 12 openAPIV3Schema
"openAPIV3Schema": {
"oneOf": [
{
"required": [
"spec"
]
},
{
"required": [
"specs"
]
}
],
In case the user writes a policy that does not conform to the schema, Kubernetes will return an error, e.g.:
cat <<EOF > ./bad-cnp.yaml
apiVersion: "cilium.io/v2"
kind: CiliumNetworkPolicy
description: "Policy to test multiple rules in a single file"
metadata:
name: my-new-cilium-object
spec:
endpointSelector:
matchLabels:
app: details
track: stable
version: v1
ingress:
- fromEndpoints:
- matchLabels:
app: reviews
track: stable
version: v1
toPorts:
- ports:
- port: '65536'
protocol: TCP
rules:
http:
- method: GET
path: "/health"
EOF
kubectl create -f ./bad-cnp.yaml
...
spec.ingress.toPorts.ports.port in body should match '^(6553[0-5]|655[0-2][0-9]|65[0-4][0-9]{2}|6[0-4][0-9]{3}|[1-5][0-9]{4}|[0-9]{1,4})$'
In this case, the policy has a port out of the 0-65535 range.
Mounting BPFFS with systemd¶
Due to how systemd mounts filesystems, the mount point path must be reflected in the unit filename.
cat <<EOF | sudo tee /etc/systemd/system/sys-fs-bpf.mount
[Unit]
Description=Cilium BPF mounts
Documentation=http://docs.cilium.io/
DefaultDependencies=no
Before=local-fs.target umount.target
After=swap.target
[Mount]
What=bpffs
Where=/sys/fs/bpf
Type=bpf
[Install]
WantedBy=multi-user.target
EOF
Container Runtimes¶
CRIO¶
If you want to use CRIO, use the following YAML instead:
kubectl create -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.15/cilium-crio.yaml
kubectl create -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.14/cilium-crio.yaml
kubectl create -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.13/cilium-crio.yaml
kubectl create -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.12/cilium-crio.yaml
kubectl create -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.11/cilium-crio.yaml
kubectl create -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.10/cilium-crio.yaml
Since CRI-O does not automatically detect that a new CNI plugin has been installed, you will need to restart the CRI-O daemon for it to pick up the Cilium CNI configuration.
First make sure cilium is running:
kubectl get pods -n kube-system -o wide
NAME READY STATUS RESTARTS AGE IP NODE
cilium-mqtdz 1/1 Running 0 3m 10.0.2.15 minikube
After that you can restart CRI-O:
minikube ssh -- sudo systemctl restart crio
Finally, you need to restart the Cilium pod so it can re-mount
/var/run/crio/crio.sock which was recreated by CRI-O
kubectl delete -n kube-system pod -l k8s-app=cilium
Disable container runtime¶
If you want to run the Cilium agent on a node that will not host any
application containers, then that node may not have a container runtime
installed at all. You may still want to run the Cilium agent on the node to
ensure that local processes on that node can reach application containers on
other nodes. The default behavior of Cilium on startup when no container
runtime has been found is to abort startup. To avoid this abort, you can run
the cilium-agent with the following option.
--container-runtime=none
Network Policy¶
If you are running Cilium on Kubernetes, you can benefit from Kubernetes distributing policies for you. In this mode, Kubernetes is responsible for distributing the policies across all nodes and Cilium will automatically apply the policies. Two formats are available to configure network policies natively with Kubernetes:
- The standard NetworkPolicy resource which at the time of this writing, supports to specify L3/L4 ingress policies with limited egress support marked as beta.
- The extended CiliumNetworkPolicy format which is available as a
CustomResourceDefinitionwhich supports specification of policies at Layers 3-7 for both ingress and egress.
It is recommended to only use one of the above policy types at a time to minimize unintended effects arising from the interaction between the policies.
NetworkPolicy¶
For more information, see the official NetworkPolicy documentation.
Known missing features for Kubernetes Network Policy:
| Feature | Tracking Issue |
|---|---|
| Use of named ports | https://github.com/cilium/cilium/issues/2942 |
| Ingress CIDR-based L4 policy | https://github.com/cilium/cilium/issues/1684 |
CiliumNetworkPolicy¶
The CiliumNetworkPolicy is very similar to the standard NetworkPolicy. The purpose is provide the functionality which is not yet supported in NetworkPolicy. Ideally all of the functionality will be merged into the standard resource format and this CRD will no longer be required.
The raw specification of the resource in Go looks like this:
type CiliumNetworkPolicy struct {
metav1.TypeMeta `json:",inline"`
// +optional
Metadata metav1.ObjectMeta `json:"metadata"`
// Spec is the desired Cilium specific rule specification.
Spec *api.Rule `json:"spec,omitempty"`
// Specs is a list of desired Cilium specific rule specification.
Specs api.Rules `json:"specs,omitempty"`
// Status is the status of the Cilium policy rule
// +optional
Status CiliumNetworkPolicyStatus `json:"status"`
}
- Metadata
Describes the policy. This includes:
- Name of the policy, unique within a namespace
- Namespace of where the policy has been injected into
- Set of labels to identify resource in Kubernetes
- Spec
- Field which contains a Rule Basics
- Specs
- Field which contains a list of Rule Basics. This field is useful if multiple rules must be removed or added automatically.
- Status
- Provides visibility into whether the policy has been successfully applied
Examples¶
See Layer 3 Examples for a detailed list of example policies.
Endpoint CRD¶
When managing pods in Kubernetes, Cilium will create a Custom Resource
Definition (CRD) of Kind CiliumEndpoint. One CiliumEndpoint is created
for each pod managed by Cilium, with the same name and in the same namespace.
The CiliumEndpoint objects contain the same information as the json output
of cilium endpoint get under the .status field, but can be fetched for
all pods in the cluster. Adding the -o json will export more information
about each endpoint. This includes the endpoint’s labels, security identity and
the policy in effect on it.
For example:
kubectl get ciliumendpoints --all-namespaces
NAMESPACE NAME AGE
default app1-55d7944bdd-l7c8j 1h
default app1-55d7944bdd-sn9xj 1h
default app2 1h
default app3 1h
kube-system cilium-health-minikube 1h
kube-system microscope 1h
Note
Each cilium-agent pod will create a CiliumEndpoint to represent its
own inter-agent health-check endpoint. These are not pods in
Kubernetes and are in the kube-system namespace. They are named as
cilium-health-<node-name>
| orphan: |
|---|
Kubernetes Compatibility¶
Cilium is compatible with multiple Kubernetes API Groups. Some are deprecated or beta, and may only be available in specific versions of Kubernetes.
All Kubernetes versions listed are compatible with Cilium:
| k8s Version | k8s NetworkPolicy API | CiliumNetworkPolicy |
| 1.10, 1.11, 1.12, 1.13, 1.14, 1.15 | cilium.io/v2 has a
CustomResourceDefinition |
Troubleshooting¶
Verifying the installation¶
Check the status of the DaemonSet and verify that all desired instances are in
“ready” state:
$ kubectl --namespace kube-system get ds
NAME DESIRED CURRENT READY NODE-SELECTOR AGE
cilium 1 1 0 <none> 3s
In this example, we see a desired state of 1 with 0 being ready. This indicates
a problem. The next step is to list all cilium pods by matching on the label
k8s-app=cilium and also sort the list by the restart count of each pod to
easily identify the failing pods:
$ kubectl --namespace kube-system get pods --selector k8s-app=cilium \
--sort-by='.status.containerStatuses[0].restartCount'
NAME READY STATUS RESTARTS AGE
cilium-813gf 0/1 CrashLoopBackOff 2 44s
Pod cilium-813gf is failing and has already been restarted 2 times. Let’s
print the logfile of that pod to investigate the cause:
$ kubectl --namespace kube-system logs cilium-813gf
INFO _ _ _
INFO ___|_| |_|_ _ _____
INFO | _| | | | | | |
INFO |___|_|_|_|___|_|_|_|
INFO Cilium 0.8.90 f022e2f Thu, 27 Apr 2017 23:17:56 -0700 go version go1.7.5 linux/amd64
CRIT kernel version: NOT OK: minimal supported kernel version is >= 4.8
In this example, the cause for the failure is a Linux kernel running on the worker node which is not meeting System Requirements.
If the cause for the problem is not apparent based on these simple steps,
please come and seek help on our Slack channel.
Apiserver outside of cluster¶
If you are running Kubernetes Apiserver outside of your cluster for some reason (like keeping master nodes behind a firewall), make sure that you run Cilium on master nodes too. Otherwise Kubernetes pod proxies created by Apiserver will not be able to route to pod IPs and you may encounter errors when trying to proxy traffic to pods.
You may run Cilium as a static pod or set tolerations for Cilium DaemonSet to ensure that Cilium pods will be scheduled on your master nodes. The exact way to do it depends on your setup.
Istio¶
Cilium can be deployed along Istio to provide L3-L7 network filtering in complement to Istio’s microservice mesh features. The following quick guide guides you through the process step by step:
For more information on Istio, check out the Istio website.
Docker¶
Cilium can be integrated with Docker in two ways:
- via the
CNIinterface. This method is used by Kubernetes and Mesos. - via Docker’s libnetwork plugin interface, if networking is to be managed by the Docker runtime. This method is used, for example, by Docker Compose.
To run Cilium with Docker’s libnetwork, it needs a single logical Docker
network of type cilium with an IPAM-driver of type cilium. The
IPAM-driver delegates control over IPv4 and IPv6 address management and network
connectivity to Cilium for all containers attached to this network. Each Docker
container is allocated an IP address from the node prefix of the node running
that container.
When deployed with Docker, each Linux node must also run a cilium-docker
agent that receives libnetwork calls from Docker and then communicates with the
Cilium Agent to control container networking.
Security policies controlling connectivity between the Docker containers can be written in terms of the Docker container labels passed to Docker when creating the container. These policies can be created and updated via the Cilium agent API or by using the Cilium CLI client.
Follow this guide for a step by step introduction on how to use Cilium with Docker Compose:
Mesos¶
Cilium can be integrated with Apache Mesos and Marathon using the CNI plugin. The following quick guide guides you through the process step by step:
For more information on Apache Mesos and Marathon orchestration, check out the Mesos and Marathon GitHub pages, respectively.
Envoy¶
Envoy Go Extensions¶
Note
This feature is currently in beta phase.
This is a guide for developers who are interested in writing a Go extension to the Envoy proxy as part of Cilium.
As depicted above, this framework allows a developer to write a small amount of Go code (green box) focused on parsing a new API protocol, and this Go code is able to take full advantage of Cilium features including high-performance redirection to/from Envoy, rich L7-aware policy language and access logging, and visibility into encrypted traffic traffic via kTLS (coming soon!). In sum, you as the developer need only worry about the logic of parsing the protocol, and Cilium + Envoy + BPF do the heavy-lifting.
This guide uses simple examples based on a hypothetical “r2d2” protocol (see proxylib/r2d2/r2d2parser.go) that might be used to talk to a simple protocol droid a long time ago in a galaxy far, far away. But it also points to other real protocols like Memcached and Cassandra that already exist in the cilium/proxylib directory.
Step 1: Decide on a Basic Policy Model¶
To get started, take some time to think about what it means to provide protocol-aware security in the context of your chosen protocol. Most protocols follow a common pattern of a client who performs an ‘’operation’’ on a ‘’resource’‘. For example:
- A standard RESTful HTTP request has a GET/POST/PUT/DELETE methods (operation) and URLs (resource).
- A database protocol like MySQL has SELECT/INSERT/UPDATE/DELETE actions (operation) on a combined database + table name (resource).
- A queueing protocol like Kafka has produce/consume (operation) on a particular queue (resource).
A common policy model is to allow the user to whitelist certain operations on one or more resources. In some cases, the resources need to support regexes to avoid explicit matching on variable content like ids (e.g., /users/<uuid> would match /users/.*)
In our examples, the ‘’r2d2’’ example, we’ll use a basic set of operations (READ/WRITE/HALT/RESET). The READ and WRITE commands also support a ‘filename’ resource, while HALT and RESET have no resource.
Step 2: Understand Protocol, Encoding, Framing and Types¶
Next, get your head wrapped around how a protocol looks terms of the raw data, as this is what you’ll be parsing.
Try looking for official definitions of the protocol or API. Official docs will not only help you quickly learn how the protocol works, but will also help you by documenting tricky corner cases that wouldn’t be obvious just from regular use of the protocol. For example, here are example specs for Redis Protocol , Cassandra Protocol, and AWS SQS .
These specs help you understand protocol aspects like:
- encoding / framing : how to recognize the beginning/end of individual requests/replies within a TCP stream. This typically involves reading a header that encodes the overall request length, though some simple protocols use a delimiter like ‘’rn’’ to separate messages.
- request/reply fields : for most protocols, you will need to parse out fields at various offsets into the request data in order to extract security-relevant values for visibility + filtering. In some cases, access control requires filtering requests from clients to servers, but in some cases, parsing replies will also be required if reply data is required to understand future requests (e.g., prepared-statements in database protocols).
- message flow : specs often describe various dependencies between different requests. Basic protocols tend to follow a simple serial request/reply model, but more advanced protocols will support pipelining (i.e., sending multiple requests before any replies have been received).
- protocol errors : when a Cilium proxy denies a request based on policy, it should return a protocol-specific error to the client (e.g., in HTTP, a proxy should return a ‘‘403 Access Denied’’ error). Looking at the protocol spec will typically indicate how you should return an equivalent ‘’Access Denied’’ error.
Sometimes, the protocol spec does not give you a full sense of the set of commands that can be sent over the protocol. In that case, looking at higher-level user documentation can fill in some of these knowledge gaps. Here are examples for Redis Commands and Cassandra CQL Commands .
Another great trick is to use Wireshark to capture raw packet data between a client and server. For many protocols, the Wireshark Sample Captures has already saved captures for us. Otherwise, you can easily use tcpdump to capture a file. For example, for MySQL traffic on port 3306, you could run the following in a container running the MySQL client or server: “tcpdump -s 0 port 3306 -w mysql.pcap”. More Info
In our example r2d2 protocol, we’ll keep the spec as simple as possible. It is a text-only based protocol, with each request being a line terminated by ‘’rn’‘. A request starts with a case-insensitive string command (“READ”,”WRITE”,”HALT”,”RESET”). If the command is “READ” or “WRITE”, the command must be followed by a space, and a non-empty filename that contains only non whitespace ASCII characters.
Step 3: Search for Existing Parser Code / Libraries¶
Look for open source Go library/code that can help. Is there existing open source Go code that parse your protocol that you can leverage, either directly as library or a motivating example? For example, the tidwall/recon library parses Redis in Go, and Vitess parses MySQL in Go. Wireshark dissectors also has a wealth of protocol parsers written in C that can serve as useful guidance. Note: finding client-only protocol parsing code is typically less helpful than finding a proxy implementation, or a full parser library. This is because the set of requests a client parsers is typically the inverse set of the requests a Cilium proxy needs to parse, since the proxy mimics the server rather than the client. Still, viewing a Go client can give you a general idea of how to parse the general serialization format of the protocol.
Step 4: Follow the Cilium Developer Guide¶
It is easiest to start Cilium development by following the Developer / Contributor Guide
After cloning Cilium:
$ cd cilium
$ contrib/vagrant/start.sh
$ cd proxylib
While this dev VM is running, you can open additional terminals to the Cilium dev VM by running ‘’vagrant ssh’’ from within the cilium source directory.
Step 5: Create New Proxy Skeleton¶
From inside the proxylib directory, copy the rd2d directory and rename the files. Replace ‘’newproto’’ with your protocol:
$ mkdir newproto
$ cd newproto
$ cp ../r2d2/r2d2parser.go newproto.go
$ cp ../r2d2/r2d2parser_test.go newproto_test.go
Within both newproto.go and newproto_test.go update references to r2d2 with your protocol name. Search for both ‘’r2d2’’ and ‘’R2D2’‘.
Also, edit proxylib.go and add the following import line:
_ "github.com/cilium/cilium/proxylib/newproto"
Step 6: Update OnData Method¶
Implementing a parser requires you as the developer to implement three primary functions, shown as blue in the diagram below. We will cover OnData() in this section, and the other functions in section Step 9: Add Policy Loading and Matching.
The beating heart of your parsing is implementing the onData function. You can think of any proxy as have two data streams, one in the request direction (i.e., client to server) and one in the reply direction (i.e., server to client). OnData is called when there is data to process, and the value of the boolean ‘reply’ parameter indicates the direction of the stream for a given call to OnData. The data passed to OnData is a slice of byte slices (i.e., an array of byte arrays).
The return values of the OnData function tell the Go framework tell how data in the stream should be processed, with four primary outcomes:
- PASS x : The next x bytes in the data stream passed to OnData represent a request/reply that should be passed on to the server/client. The common case here is that this is a request that should be allowed by policy, or that no policy is applied. Note: x bytes may be less than the total amount of data passed to OnData, in which case the remaining bytes will still be in the data stream when onData is invoked next. x bytes may also be more than the data that has been passed to OnData. For example, in the case of a protocol where the parser filters only on values in a protocol header, it is often possible to make a filtering decision, and then pass (or drop) the size of the full request/reply without having the entire request passed to Go.
- MORE x : The buffers passed to OnData to do not represent all of the data required to frame and
filter the request/reply. Instead, the parser
needs to see at least x additional bytes beyond the current data to make a decision.
In some cases, the full request must be read to understand framing and filtering, but in others a decision
can be made simply by reading a protocol header. When parsing data, be defensive, and recognize that it is technically possible that
data arrives one byte byte at a time. Two common scenarios exist here:
- Text-based Protocols : For text-based protocols that use a delimiter like “rn”, it is common to simply check if the delimiter exists, and return MORE 1 if it does not, as technically one more character could result in the delimiter being present. See the sample r2d2 parser as a basic example of this.
- Binary-based protocols : Many binary protocols have a fixed header length, which containers a field that then indicates the remaining length of the request. In the binary case, first check to make sure a full header is received. Typically the header will indicate both the full request length (i.e., framing), as well as the request type, which indicates how much of the full request must be read in order to perform filtering (in many cases, this is less than the full request). A binary parser will typically return MORE if the data passed to OnData is less than the header length. After reading a full header, the simple approach is for the parser to return MORE to wait for the full request to be received and parsed (see the existing CassandraParser as an example). However, as an optimization, the parser can attempt to only request the minimum number of bytes required beyond the header to make a policy decision, and then PASS or DROP the remaining bytes without requiring them to be passed to the Go parser.
- DROP x : Remove the first x bytes from the data stream passed to OnData, as they represent a request/reply that should not be forwarded to the client or server based on policy. Don’t worry about making onData return a drop right away, as we’ll return to DROP in a later step below.
- ERROR y : The connection contains data that does not match the protocol spec, and prevents you from further parsing the data stream. The framework will terminate the connection. An example would be a request length that falls outside the min/max specified by the protocol spec, or values for a field that fall outside the values indicated by the spec (e.g., wrong versions, unknown commands). If you are still able to properly frame the requests, you can also choose to simply drop the request and return a protocol error (e.g., similar to an ‘’HTTP 400 Bad Request’’ error. But in all cases, you should write your parser defensively, such that you never forward a request that you do not understand, as such a request could become an avenue for subverting the intended security visibility and filtering policies. See proxylib/types.h for the set of valid error codes.
See proxylib/proxylib/parserfactory.go for the official OnData interface definition.
Keep it simple, and work iteratively. Start out just getting the framing right. Can you write a parser that just prints out the length and contents of a request, and then PASS each request with no policy enforcement?
One simple trick is to comment out the r2d2 parsing logic in OnData, but leave it in the file as a reference, as your protocol will likely require similar code as we add more functionality below.
Step 7: Use Unit Testing To Drive Development¶
Use unit tests to drive your development. Its tempting to want to first test your parser by firing up a client and server and developing on the fly. But in our experience you’ll iterate faster by using the great unit test framework created along with the Go proxy framework. This framework lets you pass in an example set of requests as byte arrays to a CheckOnDataOK method, which are passed to the parser’s OnData method. CheckOnDataOK takes a set of expected return values, and compares them to the actual return values from OnData processing the byte arrays.
Take some time to look at the unit tests for the r2d2 parser, and then for more complex parsers like Cassandra and Memcached. For simple text-based protocols, you can simply write ASCII strings to represent protocol messages, and convert them to []byte arrays and pass them to CheckOnDataOK. For binary protocols, one can either create byte arrays directly, or use a mechanism to convert a hex string to byte[] array using a helper function like hexData in cassandra/cassandraparser_test.go
A great way to get the exact data to pass in is to copy the data from the Wireshark captures mentioned above in Step #2. You can see the full application layer data streams in Wireshark by right-clicking on a packet and selecting “Follow As… TCP Stream”. If the protocol is text-based, you can copy the data as ASCII (see r2d2/r2d2parser_test.go as an example of this). For binary data, it can be easier to instead select “raw” in the drop-down, and use a basic utility to convert from ascii strings to binary raw data (see cassandra/cassandraparser_test.go for an example of this).
To run the unit tests, go to proxylib/newproto and run:
$ go test
This will build the latest version of your parser and unit test files and run the unit tests.
Step 8: Add More Advanced Parsing¶
Thinking back to step #1, what are the critical fields to parse out of the request in order to understand the “operation” and “resource” of each request. Can you print those out for each request?
Use the unit test framework to pass in increasingly complex requests, and confirm that the parser prints out the right values, and that the unit tests are properly slicing the datastream into requests and parsing out the required fields.
A couple scenarios to make sure your parser handles properly via unit tests:
- data chunks that are less than a full request (return MORE)
- requests that are spread across multiple data chunks. (return MORE ,then PASS)
- multiple requests that are bundled into a single data chunk (return PASS, then another PASS)
- rejection of malformed requests (return ERROR).
For certain advanced cases, it is required for a parser to store state across requests. In this case, data can be stored using data structures that are included as part of the main parser struct. See CassandraParser in cassandra/cassandraparser.go as an example of how the parser uses a string to store the current ‘keyspace’ in use, and uses Go maps to keep state required for handling prepared queries.
Step 9: Add Policy Loading and Matching¶
Once you have the parsing of most protocol messages ironed out, its time to start enforcing policy.
First, create a Go object that will represent a single rule in the policy language. For example, this is the rule for the r2d2 protocol, which performs exact match on the command string, and a regex on the filename:
type R2d2Rule struct {
cmdExact string
fileRegexCompiled *regexp.Regexp
}
There are two key methods to update:
- Matches : This function implements the basic logic of comparing data from a single request against a single policy rule, and return true if that rule matches (i.e., allows) that request.
- <NewProto>RuleParser : Reads key value pairs from policy, validates those entries, and stores them as a <NewProto>Rule object.
See r2d2/r2d2parser.go for examples of both functions for the r2d2 protocol.
You’ll also need to update OnData to call p.connection.Matches(), and if this function return false, return DROP for a request. Note: despite the similar names between the Matches() function you create in your newprotoparser.go and p.connection.Matches(), do not confuse the two. Your OnData function should always call p.connection.Matches() rather than invoking your own Matches() directly, as p.connection.Matches() calls the parser’s Matches() function only on the subset of L7 rules that apply for the given Cilium source identity for this particular connection.
Once you add the logic to call Matches() and return DROP in OnData, you will need to update unit tests to have policies that allow the traffic you expect to be passed. The following is an example of how r2d2/r2d2parser_test.go adds an allow-all policy for a given test:
s.ins.CheckInsertPolicyText(c, "1", []string{`
name: "cp1"
policy: 2
ingress_per_port_policies: <
port: 80
rules: <
l7_proto: "r2d2"
>
>
`})
The following is an example of a policy that would allow READ commands with a file regex of “.*”:
s.ins.CheckInsertPolicyText(c, "1", []string{`
name: "cp2"
policy: 2
ingress_per_port_policies: <
port: 80
rules: <
l7_proto: "r2d2"
l7_rules: <
rule: <
key: "cmd"
value: "READ"
>
rule: <
key: "file"
value: ".*"
>
>
>
>
>
`})
Step 10: Inject Error Response¶
Simply dropping the request from the request data stream prevents the request from reaching the server, but it would leave the client hanging, waiting for a response that would never come since the server did not see the request.
Instead, the proxy should return an application-layer reply indicating that access was denied, similar to how an HTTP proxy would return a ‘‘403 Access Denied’’ error. Look back at the protocol spec discussed in Step 2 to understand what an access denied message looks like for this protocol, and use the p.connection.Inject() method to send this error reply back to the client. See r2d2/r2d2parser.go for an example.
p.connection.Inject(true, []byte("ERROR\r\n"))
Note: p.connection.Inject() will inject the data it is passed into the reply datastream. In order for the client to parse this data correctly, it must be injected at a proper framing boundary (i.e., in between other reply messages that may be in the reply data stream). If the client is following a basic serial request/reply model per connection, this is essentially guaranteed as at the time of a request that is denied, there are no other replies potentially in the reply datastream. But if the protocol supports pipelining (i.e., multiple requests in flight) replies must be properly framed and PASSed on a per request basis, and the timing of the call to p.connection.Inject() must be controlled such that the client will properly match the Error response with the correct request. See the Memcached parser as an example of how to accomplish this.
Step 11: Add Access Logging¶
Cilium also has the notion of an ‘’Access Log’‘, which records each request handled by the proxy and indicates whether the request was allowed or denied.
A call to ‘’p.connection.Log()’’ implements access logging. See the OnData function in r2d2/r2d2parser.go as an example:
p.connection.Log(access_log_entry_type,
&cilium.LogEntry_GenericL7{
&cilium.L7LogEntry{
Proto: "r2d2",
Fields: map[string]string{
"cmd": reqData.cmd,
"file": reqData.file,
},
},
})
Step 12: Manual Testing¶
Find the standard docker container for running the protocol server. Often the same image also has a CLI client that you can use as a client.
Start both a server and client container running in the cilium dev VM, and attach them to the already created “cilium-net”. For example, with Cassandra, we run:
docker run --name cass-server -l id=cass-server -d --net cilium-net cassandra
docker run --name cass-client -l id=cass-client -d --net cilium-net cassandra sh -c 'sleep 3000'
Note that we run both containers with labels that will make it easy to refer to these containers in a cilium network policy. Note that we have the client container run the sleep command, as we will use ‘docker exec’ to access the client CLI.
Use ‘’cilium endpoint list’’ to identify the IP address of the protocol server.
$ cilium endpoint list
ENDPOINT POLICY (ingress) POLICY (egress) IDENTITY LABELS (source:key[=value]) IPv6 IPv4 STATUS
ENFORCEMENT ENFORCEMENT
2987 Disabled Disabled 31423 container:id=cass-server f00d::a0b:0:0:bab 10.11.51.247 ready
27333 Disabled Disabled 4 reserved:health f00d::a0b:0:0:6ac5 10.11.92.46 ready
50923 Disabled Disabled 18253 container:id=cass-client f00d::a0b:0:0:c6eb 10.11.175.191 ready
One can then invoke the client CLI using that server IP address (10.11.51.247 in the above example):
docker exec -it cass-client sh -c 'cqlsh 10.11.51.247 -e "select * from system.local"'
Note that in the above example, ingress policy is not enforced for the Cassandra server endpoint, so no data will flow through the Cassandra parser. A simple ‘’allow all’’ L7 Cassandra policy can be used to send all data to the Cassandra server through the Go Cassandra parser. This policy has a single empty rule, which matches all requests. An allow all policy looks like:
[ {
"endpointSelector": {"matchLabels":{"id":"cass-server"}},
"ingress": [ {
"toPorts": [{
"ports": [{"port": "9042", "protocol": "TCP"}],
"rules": {
"l7proto": "cassandra",
"l7": [{}]
}
}]
} ]
}]
A policy can be imported into cilium using ‘’cilium policy import’‘, after which another call to ‘’cilium endpoint list’’ confirms that ingress policy is now in place on the server. If the above policy was saved to a file cass-allow-all.json, one would run:
$ cilium policy import cass-allow-all.json
Revision: 1
$ cilium endpoint list
ENDPOINT POLICY (ingress) POLICY (egress) IDENTITY LABELS (source:key[=value]) IPv6 IPv4 STATUS
ENFORCEMENT ENFORCEMENT
2987 Enabled Disabled 31423 container:id=cass-server f00d::a0b:0:0:bab 10.11.51.247 ready
27333 Disabled Disabled 4 reserved:health f00d::a0b:0:0:6ac5 10.11.92.46 ready
50923 Disabled Disabled 18253 container:id=cass-client f00d::a0b:0:0:c6eb 10.11.175.191 ready
Note that policy is now showing as ‘’Enabled’’ for the Cassandra server on ingress.
To remove this or any other policy, run:
$ cilium policy delete --all
To install a new policy, first delete, and then run ‘’cilium policy import’’ again. For example, the following policy would allow select statements on a specific set of tables to this Cassandra server, but deny all other queries.
[ {
"endpointSelector": {"matchLabels":{"id":"cass-server"}},
"ingress": [ {
"toPorts": [{
"ports": [{"port": "9042", "protocol": "TCP"}],
"rules": {
"l7proto": "cassandra",
"l7": [
{ "query_action" : "select", "query_table": "^system.*"},
{ "query_action" : "select", "query_table" : "^posts_db.posts$"}
]}
}]
}]
} ]
When performing manual testing, remember that each time you change your Go proxy code, you must re-run ‘’make’’ and ‘’sudo make install’’ and then restart the cilium-agent process. If the only changes you have made since last compiling cilium are in your cilium/proxylib directory, you can safely just run ‘’make’’ and ‘’sudo make install’’ in that directory, which saves time. For example:
$ cd proxylib // only safe is this is the only directory that has changed
$ make
<snip>
$ sudo make install
<snip>
If you rebase or other files change, you need to run both commands from the top level directory.
Cilium agent default to running as a service in the development VM. However, the default options do not include the ‘’–debug-verbose=flow’’ flag, which is critical to getting visibility in troubleshooting Go proxy frameworks. So it is easiest to stop the cilium service and run the cilium-agent directly as a command in a terminal window, and adding the ‘’–debug-verbose=flow’’ flag.
$ sudo service cilium stop
$ sudo /usr/bin/cilium-agent --debug --auto-direct-node-routes --ipv4-range 10.11.0.0/16 --kvstore-opt consul.address=192.168.33.11:8500 --kvstore consul --container-runtime=docker --container-runtime-endpoint=unix:///var/run/docker.sock -t vxlan --fixed-identity-mapping=128=kv-store --fixed-identity-mapping=129=kube-dns --debug-verbose=flow --access-log=/var/log/cilium-access.log
The cilium access log is accessible from within the developer VM at ‘’/var/log/cilium-access.log’‘
Step 13: Add Runtime Tests¶
Before submitting this change to the Cilium community, it is recommended that you add runtime tests that will run as part of Cilium’s continuous integration testing. Usually these runtime test can be based on the same container images and test commands you used for manual testing.
The best approach for adding runtime tests is typically to start out by copying-and-pasting an existing L7 protocol runtime test and then updating it to run the container images and CLI commands specific to the new protocol. See cilium/test/runtime/cassandra.go as an example that matches the use of Cassandra described above in the manual testing section. Note that the json policy files used by the runtime tests are stored in cilium/test/runtime/manifests, and the Cassandra example policies in those directories are easy to use as a based for similar policies you may create for your new protocol.
Step 14: Review Spec for Corner Cases¶
Many protocols have advanced features or corner cases that will not manifest themselves as part of basic testing. Once you have written a first rev of the parser, it is a good idea to go back and review the protocol’s spec or list of commands to see what if any aspects may fall outside the scope of your initial parser. For example, corner cases like the handling of empty or nil lists may not show up in your testing, but may cause your parser to fail. Add more unit tests to cover these corner cases. It is OK for the first rev of your parser not to handle all types of requests, or to have a simplified policy structure in terms of which fields can be matched. However, it is important to know what aspects of the protocol you are not parsing, and ensure that it does not lead to any security concerns. For example, failing to parse prepared statements in a database protocol and instead just passing PREPARE and EXECUTE commands through would lead to gaping security whole that would render your other filtering meaningless in the face of a sophisticated attacker.
Step 15: Write Docs or Getting Started Guide (optional)¶
At a minimum, the policy examples included as part of the runtime tests serve as basic documentation of the policy and its expected behavior. But we also encourage adding more user friendly examples and documentation, for example, Getting Started Guides. cilium/Documentation/gettingstarted/cassandra.rst is a good example to follow. Also be sure to update Documentation/gettingstarted/index.rst with a link to this new getting started guide.
With that, you are ready to post this change for feedback from the Cilium community. Congrats!
System Requirements¶
Before installing Cilium, please ensure that your system meets the minimum requirements below. Most modern Linux distributions already do.
Summary¶
When running Cilium using the container image cilium/cilium, the host
system must meet these requirements:
- Linux kernel >= 4.9.17
- Key-Value store etcd >= 3.1.0 or consul >= 0.6.4
When running Cilium as a native process on your host (i.e. not running the
cilium/cilium container image) these additional requirements must be met:
- clang+LLVM >=5.0 (Recommended: >=7.0)
- iproute2 with BPF templating patches [1]
| Requirement | Minimum Version | In cilium container |
|---|---|---|
| Linux kernel | >= 4.9.17 | no |
| Key-Value store (etcd) | >= 3.1.0 | no |
| Key-Value store (consul) | >= 0.6.4 | no |
| clang+LLVM | >= 5.0.0 | yes |
| iproute2 | >= 5.0.0 [1] | yes |
| [1] | (1, 2) Requires support for BPF templating as documented below. |
Linux Distribution Compatibility Matrix¶
The following table lists Linux distributions that are known to work well with Cilium.
| Distribution | Minimum Version |
|---|---|
| CoreOS | stable (>= 1298.5.0) |
| Debian | >= 9 Stretch |
| Fedora Atomic/Core | >= 25 |
| LinuxKit | all |
| Ubuntu | >= 16.04.2, >= 16.10 |
| Opensuse | Tumbleweed, >=Leap 15.0 |
Note
The above list is based on feedback by users. If you find an unlisted Linux distribution that works well, please let us know by opening a GitHub issue or by creating a pull request that updates this guide.
Linux Kernel¶
Cilium leverages and builds on the kernel BPF functionality as well as various subsystems which integrate with BPF. Therefore, host systems are required to run Linux kernel version 4.8.0 or later to run a Cilium agent. More recent kernels may provide additional BPF functionality that Cilium will automatically detect and use on agent start.
In order for the BPF feature to be enabled properly, the following kernel configuration options must be enabled. This is typically the case with distribution kernels. When an option can be built as a module or statically linked, either choice is valid.
CONFIG_BPF=y
CONFIG_BPF_SYSCALL=y
CONFIG_NET_CLS_BPF=y
CONFIG_BPF_JIT=y
CONFIG_NET_CLS_ACT=y
CONFIG_NET_SCH_INGRESS=y
CONFIG_CRYPTO_SHA1=y
CONFIG_CRYPTO_USER_API_HASH=y
Note
Users running Linux 4.10 or earlier with Cilium CIDR policies may face Restrictions on unique prefix lengths for CIDR policy rules.
Key-Value store¶
Cilium uses a distributed Key-Value store to manage, synchronize and distribute security identities across all cluster nodes. The following Key-Value stores are currently supported:
- etcd >= 3.1.0
- consul >= 0.6.4
See Key-Value Store for details on how to configure the
cilium-agent to use a Key-Value store.
clang+LLVM¶
Note
This requirement is only needed if you run cilium-agent natively.
If you are using the Cilium container image cilium/cilium,
clang+LLVM is included in the container image.
LLVM is the compiler suite that Cilium uses to generate BPF bytecode programs
to be loaded into the Linux kernel. The minimum supported version of LLVM
available to cilium-agent should be >=5.0. The version of clang installed
must be compiled with the BPF backend enabled.
See https://releases.llvm.org/ for information on how to download and install LLVM.
iproute2¶
Note
iproute2 is only needed if you run cilium-agent directly on the
host machine. iproute2 is included in the cilium/cilium container
image.
iproute2 is a low level tool used to configure various networking related
subsystems of the Linux kernel. Cilium uses iproute2 to configure networking
and tc, which is part of iproute2, to load BPF programs into the kernel.
The version of iproute2 must include the BPF templating patches. See the links in the table below for documentation on how to install the correct version of iproute2 for your distribution.
| Distribution | Link |
|---|---|
| Binary (OpenSUSE) | Open Build Service |
| Source | Cilium iproute2 source |
Firewall Rules¶
If you are running Cilium in an environment that requires firewall rules to enable connectivity, you will have to add the following rules to ensure Cilium works properly.
It is recommended but optional that all nodes running Cilium in a given cluster must be able to ping each other so cilium-health can report and monitor connectivity among nodes. This requires ICMP Type 0/8, Code 0 open among all nodes. TCP 4240 should also be open among all nodes for cilium-health monitoring. Note that it is also an option to only use one of these two methods to enable health monitoring. If the firewall does not permit either of these methods, Cilium will still operate fine but will not be able to provide health information.
If you are using VXLAN overlay network mode, Cilium uses Linux’s default VXLAN port 8472 over UDP, unless Linux has been configured otherwise. In this case, UDP 8472 must be open among all nodes to enable VXLAN overlay mode. The same applies to Geneve overlay network mode, except the port is UDP 6081.
If you are running in direct routing mode, your network must allow routing of pod IPs.
As an example, if you are running on AWS with VXLAN overlay networking, here is a minimum set of AWS Security Group (SG) rules. It assumes a separation between the SG on the master nodes, master-sg, and the worker nodes, worker-sg. It also assumes etcd is running on the master nodes.
Master Nodes (master-sg) Rules:
| Port Range / Protocol | Ingress/Egress | Source/Destination | Description |
|---|---|---|---|
| 2379-2380/tcp | ingress | worker-sg |
etcd access |
| 8472/udp | ingress | master-sg (self) |
VXLAN overlay |
| 8472/udp | ingress | worker-sg |
VXLAN overlay |
| 4240/tcp | ingress | master-sg (self) |
health checks |
| 4240/tcp | ingress | worker-sg |
health checks |
| ICMP 8/0 | ingress | master-sg (self) |
health checks |
| ICMP 8/0 | ingress | worker-sg |
health checks |
| 8472/udp | egress | master-sg (self) |
VXLAN overlay |
| 8472/udp | egress | worker-sg |
VXLAN overlay |
| 4240/tcp | egress | master-sg (self) |
health checks |
| 4240/tcp | egress | worker-sg |
health checks |
| ICMP 8/0 | egress | master-sg (self) |
health checks |
| ICMP 8/0 | egress | worker-sg |
health checks |
Worker Nodes (worker-sg):
| Port Range / Protocol | Ingress/Egress | Source/Destination | Description |
|---|---|---|---|
| 8472/udp | ingress | master-sg |
VXLAN overlay |
| 8472/udp | ingress | worker-sg (self) |
VXLAN overlay |
| 4240/tcp | ingress | master-sg |
health checks |
| 4240/tcp | ingress | worker-sg (self) |
health checks |
| ICMP 8/0 | ingress | master-sg |
health checks |
| ICMP 8/0 | ingress | worker-sg (self) |
health checks |
| 8472/udp | egress | master-sg |
VXLAN overlay |
| 8472/udp | egress | worker-sg (self) |
VXLAN overlay |
| 4240/tcp | egress | master-sg |
health checks |
| 4240/tcp | egress | worker-sg (self) |
health checks |
| ICMP 8/0 | egress | master-sg |
health checks |
| ICMP 8/0 | egress | worker-sg (self) |
health checks |
| 2379-2380/tcp | egress | master-sg |
etcd access |
Note
If you use a shared SG for the masters and workers, you can condense these rules into ingress/egress to self. If you are using Direct Routing mode, you can condense all rules into ingress/egress ANY port/protocol to/from self.
Privileges¶
The following privileges are required to run Cilium. When running the standard
Kubernetes DaemonSet, the privileges are automatically granted to Cilium.
Cilium interacts with the Linux kernel to install BPF program which will then perform networking tasks and implement security rules. In order to install BPF programs system-wide,
CAP_SYS_ADMINprivileges are required. These privileges must be granted tocilium-agent.The quickest way to meet the requirement is to run
cilium-agentas root and/or as privileged container.Cilium requires access to the host networking namespace. For this purpose, the Cilium pod is scheduled to run in the host networking namespace directly.
Upgrade Guide¶
This upgrade guide is intended for Cilium 1.3 or later running on Kubernetes. It is assuming that Cilium has been deployed using standard procedures as described in the Deployment. If you have installed Cilium using the guide Requirements, then this is automatically the case. If you are looking for instructions for upgrading from a version of Cilium prior to 1.3, then please consult the documentation from that release.
Running a pre-flight DaemonSet¶
When rolling out an upgrade with Kubernetes, Kubernetes will first terminate the pod followed by pulling the new image version and then finally spin up the new image. In order to reduce the downtime of the agent, the new image version can be pre-pulled. It also verifies that the new image version can be pulled and avoids ErrImagePull errors during the rollout.
$ kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.10/cilium-pre-flight.yaml
$ kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.11/cilium-pre-flight.yaml
$ kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.12/cilium-pre-flight.yaml
$ kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.13/cilium-pre-flight.yaml
$ kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.14/cilium-pre-flight.yaml
$ kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.15/cilium-pre-flight.yaml
After running the cilium-pre-flight.yaml, make sure the number of READY pods is the same number of Cilium pods running.
kubectl get daemonset -n kube-system | grep cilium
NAME DESIRED CURRENT READY UP-TO-DATE AVAILABLE NODE SELECTOR AGE
cilium 2 2 2 2 2 <none> 1h20m
cilium-pre-flight-check 2 2 2 2 2 <none> 7m15s
Once the number of READY pods are the same, you can delete cilium-pre-flight-check
DaemonSet and proceed with the upgrade.
kubectl -n kube-system delete ds cilium-pre-flight-check
Upgrading Micro Versions¶
Micro versions within a particular minor version, e.g. 1.2.x -> 1.2.y, are
always 100% compatible for both up- and downgrades. Upgrading or downgrading is
as simple as changing the image tag version in the DaemonSet file:
kubectl -n kube-system set image daemonset/cilium cilium-agent=docker.io/cilium/cilium:vX.Y.Z
kubectl -n kube-system rollout status daemonset/cilium
Kubernetes will automatically restart all Cilium according to the
UpgradeStrategy specified in the DaemonSet.
Note
Direct version upgrade between minor versions is not recommended as RBAC and DaemonSet definitions are subject to change between minor versions. See Upgrading Minor Versions for instructions on how to up or downgrade between different minor versions.
Upgrading Minor Versions¶
Step 1: Upgrade to latest micro version (Recommended)¶
When upgrading from one minor release to another minor release, for example 1.x to 1.y, it is recommended to first upgrade to the latest micro release as documented in (Upgrading Micro Versions). This ensures that downgrading by rolling back on a failed minor release upgrade is always possible and seamless.
Step 2: Upgrade the ConfigMap (Optional)¶
The configuration of Cilium is stored in a ConfigMap called
cilium-config. The format is compatible between minor releases so
configuration parameters are automatically preserved across upgrades. However,
new minor releases may introduce new functionality that require opt-in via the
ConfigMap. Refer to the Version Specific Notes for a list of new
configuration options for each minor version.
Refer to the section Upgrading a ConfigMap for instructions on how to
upgrade a ConfigMap to the latest template while preserving your
configuration parameters.
Step 3: Apply new RBAC and DaemonSet definitions¶
As minor versions typically introduce new functionality which require changes
to the DaemonSet and RBAC definitions, the YAML definitions have to be
upgraded. The following links refer to version specific DaemonSet files which
automatically
Both files are dedicated to “v1.5” for each Kubernetes version.
kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.10/cilium-rbac.yaml kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.10/cilium-ds.yaml kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.10/cilium-operator-sa.yaml kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.10/cilium-operator.yaml
kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.11/cilium-rbac.yaml kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.11/cilium-ds.yaml kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.11/cilium-operator-sa.yaml kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.11/cilium-operator.yaml
kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.12/cilium-rbac.yaml kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.12/cilium-ds.yaml kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.12/cilium-operator-sa.yaml kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.12/cilium-operator.yaml
kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.13/cilium-rbac.yaml kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.13/cilium-ds.yaml kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.13/cilium-operator-sa.yaml kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.13/cilium-operator.yaml
kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.14/cilium-rbac.yaml kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.14/cilium-ds.yaml kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.14/cilium-operator-sa.yaml kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.14/cilium-operator.yaml
kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.15/cilium-rbac.yaml kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.15/cilium-ds.yaml kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.15/cilium-operator-sa.yaml kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.15/cilium-operator.yaml
Below we will show examples of how Cilium should be upgraded using Kubernetes
rolling upgrade functionality in order to preserve any existing Cilium
configuration changes (e.g., etc configuration) and minimize network
disruptions for running workloads. These instructions upgrade Cilium to version
“v1.5” by updating the ConfigMap, RBAC rules and
DaemonSet files separately. Rather than installing all configuration in one
cilium.yaml file, which could override any custom ConfigMap
configuration, installing these files separately allows upgrade to be staged
and for user configuration to not be affected by the upgrade.
Rolling Back¶
Occasionally, it may be necessary to undo the rollout because a step was missed
or something went wrong during upgrade. To undo the rollout, change the image
tag back to the previous version or undo the rollout using kubectl:
$ kubectl rollout undo daemonset/cilium -n kube-system
This will revert the latest changes to the Cilium DaemonSet and return
Cilium to the state it was in prior to the upgrade.
Note
When rolling back after new features of the new minor version have already
been consumed, consult an eventual existing downgrade section in the
Version Specific Notes to check and prepare for incompatible feature use
before downgrading/rolling back. This step is only required after new
functionality introduced in the new minor version has already been
explicitly used by importing policy or by opting into new features via the
ConfigMap.
Version Specific Notes¶
This section documents the specific steps required for upgrading from one version of Cilium to another version of Cilium. There are particular version transitions which are suggested by the Cilium developers to avoid known issues during upgrade, then subsequently there are sections for specific upgrade transitions, ordered by version.
The table below lists suggested upgrade transitions, from a specified current
version running in a cluster to a specified target version. If a specific
combination is not listed in the table below, then it may not be safe. In that
case, consider staging the upgrade, for example upgrading from 1.1.x to the
latest 1.1.y release before subsequently upgrading to 1.2.z.
| Current version | Target version | DaemonSet upgrade |
L3 impact | L7 impact |
|---|---|---|---|---|
1.0.x |
1.1.y |
Required | N/A | Clients must reconnect[1] |
1.1.x |
1.2.y |
Required | Temporary disruption[2] | Clients must reconnect[1] |
1.2.x |
1.3.y |
Required | Minimal to None | Clients must reconnect[1] |
>=1.2.5 |
1.5.y |
Required | Minimal to None | Clients must reconnect[1] |
Annotations:
- Clients must reconnect: Any traffic flowing via a proxy (for example, because an L7 policy is in place) will be disrupted during upgrade. Endpoints communicating via the proxy must reconnect to re-establish connections.
- Temporary disruption: All traffic may be temporarily disrupted during upgrade. Connections should successfully re-establish without requiring clients to reconnect.
1.5 Upgrade Notes¶
Regression warning¶
Note
Cilium versions 1.5.0 and 1.5.1 contain two serious regressions, do not use either version.
- The load-balancing layer contained a defect which could result in incorrect routing decisions being made as well as reverse NAT not being performed correctly.
- A bug in the handling of kvstore keys resulted in the lease of kvstore keys to not be updated correctly after a restart of the agent. This would result in the deletion of all keys subject to the lease about 15-30 minutes after the agent was last restarted. The majority of kvstore keys would get re-created immediately by the owning agent to recover. However, ipcache entries which would remain lost for about 5 minutes until a periodic synchronization kicked in or until pods were restarted.
Upgrading from >=1.4.0 to 1.5.y¶
In v1.4, the TCP conntrack table size
ct-global-max-entries-tcpConfigMap parameter was ineffective due to a bug and thus, the default value (1000000) was used instead. To prevent from breaking established TCP connections,bpf-ct-global-tcp-maxmust be set to1000000in the ConfigMap before upgrading. Refer to the section Upgrading a ConfigMap on how to upgrade theConfigMap.If you previously upgraded to v1.5, downgraded to <v1.5, and now want to upgrade to v1.5 again, then you must run the following
DaemonSetbefore doing the upgrade:$ kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.10/cilium-pre-flight-with-rm-svc-v2.yaml
$ kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.11/cilium-pre-flight-with-rm-svc-v2.yaml
$ kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.12/cilium-pre-flight-with-rm-svc-v2.yaml
$ kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.13/cilium-pre-flight-with-rm-svc-v2.yaml
$ kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.14/cilium-pre-flight-with-rm-svc-v2.yaml
$ kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.15/cilium-pre-flight-with-rm-svc-v2.yaml
See Running a pre-flight DaemonSet for instructions how to run, validate and remove a pre-flight
DaemonSet.Follow the standard procedures to perform the upgrade as described in Upgrading Minor Versions.
New Default Values¶
- The connection-tracking garbage collector interval is now dynamic. It will automatically adjust based n on the percentage of the connection tracking table that has been cleared in the last run. The interval will vary between 10 seconds and 30 minutes or 12 hours for LRU based maps. This should automatically optimize CPU consumption as much as possible while keeping the connection tracking table utilization below 25%. If needed, the interval can be set to a static interval with the option
--conntrack-gc-interval. If connectivity fails andcilium monitor --type dropshowsxx drop (CT: Map insertion failed), then it is likely that the connection tracking table is filling up and the automatic adjustment of the garbage collector interval is insufficient. Set--conntrack-gc-intervalto an interval lower than the default. Alternatively, the value forbpf-ct-global-any-maxandbpf-ct-global-tcp-maxcan be increased. Setting both of these options will be a trade-off of CPU forconntrack-gc-interval, and forbpf-ct-global-any-maxandbpf-ct-global-tcp-maxthe amount of memory consumed.
New ConfigMap Options¶
All options available in the cilium-agent can now be specified in the Cilium ConfigMap without requiring to set an environment variable in the DaemonSet.
enable-k8s-event-handover: enables use of the kvstore to optimize Kubernetes event handling by listening for k8s events in the operator and mirroring it into the kvstore for reduced overhead in large clusters.enable-legacy-services: enables legacy services (prior v1.5) to prevent from terminating established connections to services when upgrading Cilium from < v1.5 to v1.5. When the option is not disabled, legacy services are enabled by default. Legacy services need to stay enabled until a user is confident that they will not need to downgrade to < v1.5 anymore. Disabling and then enabling legacy services is not possible without breaking the established connections fromPodtoService.
Deprecated Options¶
--conntrack-garbage-collector-intervalhas been deprecated. Please use the option--conntrack-gc-intervalwhich parses a duration as string instead of a integer in seconds. Support for the deprecated option will be removed in 1.6.legacy-host-allows-worldoption is now removed as planned.monitor-aggregation-level: Superseded bymonitor-aggregation.ct-global-max-entries-tcp: Superseded bybpf-ct-global-tcp-max.ct-global-max-entries-other: Superseded bybpf-ct-global-any-max.prometheus-serve-addrfrom thecilium-metrics-configConfigMap is superseded byprometheus-serve-addrfrom thecilium-configConfigMap.--auto-ipv6-node-routeswas removed as planned. Use--auto-direct-node-routesinstead.
1.4 Upgrade Notes¶
Upgrading from >=1.2.5 to 1.4.y¶
- Follow the standard procedures to perform the upgrade as described in Upgrading Minor Versions.
Changes that may require action¶
- The
--serveoption was removed from cilium-bugtool in favor of a much reduced binary size. If you want to continue using the option, please use an older version of the cilium-bugtool binary.- The DNS Polling option used by
toFQDNs.matchNamerules is disabled by default in 1.4.x due to limitations in the implementation. It has been replaced by DNS Proxy support, which must be explicitly enabled via changes to the policy described below. To ease upgrade, users may opt to enable the DNS Polling in v1.4.x by adding the--tofqdns-enable-polleroption to cilium-agent without changing policies. For instructions on how to safely upgrade see Upgrading DNS Polling deployments to DNS Proxy.- The DaemonSet now uses
dnsPolicy: ClusterFirstWithHostNetin order for Cilium to look up Kubernetes service names via DNS. This in turn requires the cluster to run a cluster DNS such as kube-dns or CoreDNS. If you are not running cluster DNS, remove thednsPolicyfield. This will mean that you cannot use the etcd-operator. More details can be found in the kube-dns section.
New ConfigMap Options¶
enable-ipv4: Iftrue, all endpoints are allocated an IPv4 address.enable-ipv6: Iftrue, all endpoints are allocated an IPv6 address.preallocate-bpf-maps: Iftrue, reduce per-packet latency at the expense of up-front memory allocation for entries in BPF maps. If this value is modified, then during the next Cilium startup the restore of existing endpoints and tracking of ongoing connections may be disrupted. This may lead to policy drops or a change in loadbalancing decisions for a connection for some time. Endpoints may need to be recreated to restore connectivity. If this option is set tofalseduring an upgrade to 1.4.0 or later, then it may cause one-time disruptions during the upgrade.auto-direct-node-routes: Iftrue, then enable automatic L2 routing between nodes. This is useful when running in direct routing mode and can be used as an alternative to running a routing daemon. Routes to other Cilium managed nodes will then be installed on automatically.install-iptables-rules: If set tofalsethen Cilium will not install any iptables rules which are mainly for interaction with kube-proxy. By default it is set totrue.masquerade: The agent can optionally be set up for masquerading all network traffic leaving the main networking device ifmasqueradeis set totrue. By default it is set tofalse.datapath-mode: Cilium can operate in two different datapath modes, that is, either based uponvethdevices (default) oripvlandevices (beta). The latter requires an additional setting to specify the ipvlan master device.- New ipvlan-specific CNI integration mode options (beta):
ipvlan-master-device: When running Cilium in ipvlan datapath mode, an ipvlan master device must be specified. This is typically pointing to a networking device that is facing the external network. Be aware that this will be used by all nodes, so it is required that the device name is consistent on all nodes where this is going to be deployed.- New flannel-specific CNI integration mode options (beta):
flannel-master-device: When running Cilium with policy enforcement enabled on top of Flannel, the BPF programs will be installed on the network interface specified in this option and on each network interface belonging to a pod.flannel-uninstall-on-exit: Ifflannel-master-deviceis specified, this determines whether Cilium should remove BPF programs from the master device and interfaces belonging to pods when the CiliumDaemonSetis deleted. If true, Cilium will remove programs from the pods.flannel-manage-existing-containers: On startup, install a BPF programs to allow for policy enforcement on pods that are currently managed by Flannel. This also requires the CiliumDaemonSetto be running withhostPID: true, which is not enabled by default.
Deprecated ConfigMap Options¶
disable-ipv4: Superseded byenable-ipv4, with the logic reversed.legacy-host-allows-world: This option allowed users to specify Cilium 1.0-style policies that treated traffic that is masqueraded from the outside world as though it arrived from the local host. As of Cilium 1.4, the option is disabled by default if not specified in the ConfigMap, and the option is scheduled to be removed in Cilium 1.5 or later.
1.3 Upgrade Notes¶
Upgrading from 1.2.x to 1.3.y¶
- If you are running Cilium 1.0.x or 1.1.x, please upgrade to 1.2.x first. It is also possible to upgrade from 1.0 or 1.1 directly to 1.3 by combining the upgrade instructions for each minor release. See the documentation for said releases for further information.
- Upgrade to Cilium
1.2.4or later using the guide Upgrading Micro Versions. - Follow the standard procedures to perform the upgrade as described in Upgrading Minor Versions.
New ConfigMap Options¶
ct-global-max-entries-tcp/ct-global-max-entries-other:Specifies the maximum number of connections supported across all endpoints, split by protocol: tcp or other. One pair of maps uses these values for IPv4 connections, and another pair of maps use these values for IPv6 connections. If these values are modified, then during the next Cilium startup the tracking of ongoing connections may be disrupted. This may lead to brief policy drops or a change in loadbalancing decisions for a connection.clean-cilium-bpf-state: Similar toclean-cilium-statebut only cleans the BPF state while preserving all other state. Endpoints will still be restored and IP allocations will prevail but all datapath state is cleaned when Cilium starts up. Not required for normal operation.
Advanced¶
Upgrade Impact¶
Upgrades are designed to have minimal impact on your running deployment. Networking connectivity, policy enforcement and load balancing will remain functional in general. The following is a list of operations that will not be available during the upgrade:
- API aware policy rules are enforced in user space proxies and are currently running as part of the Cilium pod unless Cilium is configured to run in Istio mode. Upgrading Cilium will cause the proxy to restart which will result in a connectivity outage and connection to be reset.
- Existing policy will remain effective but implementation of new policy rules will be postponed to after the upgrade has been completed on a particular node.
- Monitoring components such as
cilium monitorwill experience a brief outage while the Cilium pod is restarting. Events are queued up and read after the upgrade. If the number of events exceeds the event buffer size, events will be lost.
Upgrading a ConfigMap¶
This section describes the procedure to upgrade an existing ConfigMap to the
template of another version.
Export the current ConfigMap¶
$ kubectl get configmap -n kube-system cilium-config -o yaml --export > cilium-cm-old.yaml
$ cat ./cilium-cm-old.yaml
apiVersion: v1
data:
clean-cilium-state: "false"
debug: "true"
disable-ipv4: "false"
etcd-config: |-
---
endpoints:
- https://192.168.33.11:2379
#
# In case you want to use TLS in etcd, uncomment the 'ca-file' line
# and create a kubernetes secret by following the tutorial in
# https://cilium.link/etcd-config
ca-file: '/var/lib/etcd-secrets/etcd-client-ca.crt'
#
# In case you want client to server authentication, uncomment the following
# lines and add the certificate and key in cilium-etcd-secrets below
key-file: '/var/lib/etcd-secrets/etcd-client.key'
cert-file: '/var/lib/etcd-secrets/etcd-client.crt'
kind: ConfigMap
metadata:
creationTimestamp: null
name: cilium-config
selfLink: /api/v1/namespaces/kube-system/configmaps/cilium-config
In the ConfigMap above, we can verify that Cilium is using debug with
true, it has a etcd endpoint running with TLS,
and the etcd is set up to have client to server authentication.
Download the ConfigMap with the changes for v1.5¶
$ wget https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.10/cilium-cm.yaml
$ wget https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.11/cilium-cm.yaml
$ wget https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.12/cilium-cm.yaml
$ wget https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.13/cilium-cm.yaml
$ wget https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.14/cilium-cm.yaml
$ wget https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.15/cilium-cm.yaml
Verify its contents:
---
apiVersion: v1
kind: ConfigMap
metadata:
name: cilium-config
namespace: kube-system
data:
# This etcd-config contains the etcd endpoints of your cluster. If you use
# TLS please make sure you follow the tutorial in https://cilium.link/etcd-config
etcd-config: |-
---
endpoints:
- https://cilium-etcd-client.kube-system.svc:2379
#
# In case you want to use TLS in etcd, uncomment the 'ca-file' line
# and create a kubernetes secret by following the tutorial in
# https://cilium.link/etcd-config
ca-file: '/var/lib/etcd-secrets/etcd-client-ca.crt'
#
# In case you want client to server authentication, uncomment the following
# lines and create a kubernetes secret by following the tutorial in
# https://cilium.link/etcd-config
key-file: '/var/lib/etcd-secrets/etcd-client.key'
cert-file: '/var/lib/etcd-secrets/etcd-client.crt'
# If you want to run cilium in debug mode change this value to true
debug: "false"
# If you want metrics enabled in all of your Cilium agents, set the port for
# which the Cilium agents will have their metrics exposed.
# This option deprecates the "prometheus-serve-addr" in the
# "cilium-metrics-config" ConfigMap
# NOTE that this will open the port on ALL nodes where Cilium pods are
# scheduled.
# prometheus-serve-addr: ":9090"
# Enable IPv4 addressing. If enabled, all endpoints are allocated an IPv4
# address.
enable-ipv4: "true"
# Enable IPv6 addressing. If enabled, all endpoints are allocated an IPv6
# address.
enable-ipv6: "false"
# If a serious issue occurs during Cilium startup, this
# invasive option may be set to true to remove all persistent
# state. Endpoints will not be restored using knowledge from a
# prior Cilium run, so they may receive new IP addresses upon
# restart. This also triggers clean-cilium-bpf-state.
clean-cilium-state: "false"
# If you want to clean cilium BPF state, set this to true;
# Removes all BPF maps from the filesystem. Upon restart,
# endpoints are restored with the same IP addresses, however
# any ongoing connections may be disrupted briefly.
# Loadbalancing decisions will be reset, so any ongoing
# connections via a service may be loadbalanced to a different
# backend after restart.
clean-cilium-bpf-state: "false"
# Users who wish to specify their own custom CNI configuration file must set
# custom-cni-conf to "true", otherwise Cilium may overwrite the configuration.
custom-cni-conf: "false"
# If you want cilium monitor to aggregate tracing for packets, set this level
# to "low", "medium", or "maximum". The higher the level, the less packets
# that will be seen in monitor output.
monitor-aggregation: "none"
# ct-global-max-entries-* specifies the maximum number of connections
# supported across all endpoints, split by protocol: tcp or other. One pair
# of maps uses these values for IPv4 connections, and another pair of maps
# use these values for IPv6 connections.
#
# If these values are modified, then during the next Cilium startup the
# tracking of ongoing connections may be disrupted. This may lead to brief
# policy drops or a change in loadbalancing decisions for a connection.
#
# For users upgrading from Cilium 1.2 or earlier, to minimize disruption
# during the upgrade process, comment out these options.
bpf-ct-global-tcp-max: "524288"
bpf-ct-global-any-max: "262144"
# Pre-allocation of map entries allows per-packet latency to be reduced, at
# the expense of up-front memory allocation for the entries in the maps. The
# default value below will minimize memory usage in the default installation;
# users who are sensitive to latency may consider setting this to "true".
#
# This option was introduced in Cilium 1.4. Cilium 1.3 and earlier ignore
# this option and behave as though it is set to "true".
#
# If this value is modified, then during the next Cilium startup the restore
# of existing endpoints and tracking of ongoing connections may be disrupted.
# This may lead to policy drops or a change in loadbalancing decisions for a
# connection for some time. Endpoints may need to be recreated to restore
# connectivity.
#
# If this option is set to "false" during an upgrade from 1.3 or earlier to
# 1.4 or later, then it may cause one-time disruptions during the upgrade.
preallocate-bpf-maps: "false"
# Regular expression matching compatible Istio sidecar istio-proxy
# container image names
sidecar-istio-proxy-image: "cilium/istio_proxy"
# Encapsulation mode for communication between nodes
# Possible values:
# - disabled
# - vxlan (default)
# - geneve
tunnel: "vxlan"
# Name of the cluster. Only relevant when building a mesh of clusters.
cluster-name: default
# Unique ID of the cluster. Must be unique across all conneted clusters and
# in the range of 1 and 255. Only relevant when building a mesh of clusters.
#cluster-id: 1
# Interface to be used when running Cilium on top of a CNI plugin.
# For flannel, use "cni0"
flannel-master-device: ""
# When running Cilium with policy enforcement enabled on top of a CNI plugin
# the BPF programs will be installed on the network interface specified in
# 'flannel-master-device' and on all network interfaces belonging to
# a container. When the Cilium DaemonSet is removed, the BPF programs will
# be kept in the interfaces unless this option is set to "true".
flannel-uninstall-on-exit: "false"
# Installs a BPF program to allow for policy enforcement in already running
# containers managed by Flannel.
# NOTE: This requires Cilium DaemonSet to be running in the hostPID.
# To run in this mode in Kubernetes change the value of the hostPID from
# false to true. Can be found under the path `spec.spec.hostPID`
flannel-manage-existing-containers: "false"
# DNS Polling periodically issues a DNS lookup for each `matchName` from
# cilium-agent. The result is used to regenerate endpoint policy.
# DNS lookups are repeated with an interval of 5 seconds, and are made for
# A(IPv4) and AAAA(IPv6) addresses. Should a lookup fail, the most recent IP
# data is used instead. An IP change will trigger a regeneration of the Cilium
# policy for each endpoint and increment the per cilium-agent policy
# repository revision.
#
# This option is disabled by default starting from version 1.4.x in favor
# of a more powerful DNS proxy-based implementation, see [0] for details.
# Enable this option if you want to use FQDN policies but do not want to use
# the DNS proxy.
#
# To ease upgrade, users may opt to set this option to "true".
# Otherwise please refer to the Upgrade Guide [1] which explains how to
# prepare policy rules for upgrade.
#
# [0] http://docs.cilium.io/en/stable/policy/language/#dns-based
# [1] http://docs.cilium.io/en/stable/install/upgrade/#changes-that-may-require-action
tofqdns-enable-poller: "false"
# wait-bpf-mount makes init container wait until bpf filesystem is mounted
wait-bpf-mount: "false"
# Enable legacy services (prior v1.5) to prevent from terminating existing
# connections with services when upgrading Cilium from < v1.5 to v1.5.
enable-legacy-services: "false"
Add new options¶
Add the new options manually to your old ConfigMap, and make the necessary
changes.
In this example, the debug option is meant to be kept with true, the
etcd-config is kept unchanged, and legacy-host-allows-world is a new
option, but after reading the Version Specific Notes the value was kept unchanged
from the default value.
After making the necessary changes, the old ConfigMap was migrated with the
new options while keeping the configuration that we wanted:
$ cat ./cilium-cm-old.yaml
apiVersion: v1
data:
debug: "true"
disable-ipv4: "false"
# If you want to clean cilium state; change this value to true
clean-cilium-state: "false"
legacy-host-allows-world: "false"
etcd-config: |-
---
endpoints:
- https://192.168.33.11:2379
#
# In case you want to use TLS in etcd, uncomment the 'ca-file' line
# and create a kubernetes secret by following the tutorial in
# https://cilium.link/etcd-config
ca-file: '/var/lib/etcd-secrets/etcd-client-ca.crt'
#
# In case you want client to server authentication, uncomment the following
# lines and add the certificate and key in cilium-etcd-secrets below
key-file: '/var/lib/etcd-secrets/etcd-client.key'
cert-file: '/var/lib/etcd-secrets/etcd-client.crt'
kind: ConfigMap
metadata:
creationTimestamp: null
name: cilium-config
selfLink: /api/v1/namespaces/kube-system/configmaps/cilium-config
Apply new ConfigMap¶
After adding the options, manually save the file with your changes and install
the ConfigMap in the kube-system namespace of your cluster.
$ kubectl apply -n kube-system -f ./cilium-cm-old.yaml
As the ConfigMap is successfully upgraded we can start upgrading Cilium
DaemonSet and RBAC which will pick up the latest configuration from the
ConfigMap.
Restrictions on unique prefix lengths for CIDR policy rules¶
The Linux kernel applies limitations on the complexity of BPF code that is loaded into the kernel so that the code may be verified as safe to execute on packets. Over time, Linux releases become more intelligent about the verification of programs which allows more complex programs to be loaded. However, the complexity limitations affect some features in Cilium depending on the kernel version that is used with Cilium.
One such limitation affects Cilium’s configuration of CIDR policies. On Linux kernels 4.10 and earlier, this manifests as a restriction on the number of unique prefix lengths supported in CIDR policy rules.
Unique prefix lengths are counted by looking at the prefix portion of CIDR
rules and considering which prefix lengths are unique. For example, in the
following policy example, the toCIDR section specifies a /32, and the
toCIDRSet section specifies a /8 with a /12 removed from it. In
addition, three prefix lengths are always counted: the host prefix length for
the protocol (IPv4: /32, IPv6: /128), the default prefix length
(/0), and the cluster prefix length (default IPv4: /8, IPv6: /64).
All in all, the following example counts as seven unique prefix lengths in IPv4:
/32(fromtoCIDR, also from host prefix)/12(fromtoCIDRSet)/11(fromtoCIDRSet)/10(fromtoCIDRSet)o9(fromtoCIDRSet)/8(from cluster prefix)/0(from default prefix)
apiVersion: "cilium.io/v2"
kind: CiliumNetworkPolicy
metadata:
name: "cidr-rule"
spec:
endpointSelector:
matchLabels:
app: myService
egress:
- toCIDR:
- 20.1.1.1/32
- toCIDRSet:
- cidr: 10.0.0.0/8
except:
- 10.96.0.0/12
[{
"labels": [{"key": "name", "value": "cidr-rule"}],
"endpointSelector": {"matchLabels":{"app":"myService"}},
"egress": [{
"toCIDR": [
"20.1.1.1/32"
]
}, {
"toCIDRSet": [{
"cidr": "10.0.0.0/8",
"except": [
"10.96.0.0/12"
]}
]
}]
}]
Affected versions¶
- Any version of Cilium running on Linux 4.10 or earlier
When a CIDR policy with too many unique prefix lengths is imported, Cilium will reject the policy with a message like the following:
$ cilium policy import too_many_cidrs.json
Error: Cannot import policy: [PUT /policy][500] putPolicyFailure too many
egress CIDR prefix lengths (128/40)
$ cilium policy import too_many_cidrs.json
Error: Cannot import policy: [PUT /policy][500] putPolicyFailure Adding
specified prefixes would result in too many prefix lengths (current: 3,
result: 32, max: 18)
The supported count of unique prefix lengths may differ between Cilium minor releases, for example Cilium 1.1 supports 20 unique prefix lengths on Linux 4.10 or older, while Cilium 1.2 only supports 18 (for IPv4) or 4 (for IPv6).
Mitigation¶
Users may construct CIDR policies that use fewer unique prefix lengths. This can be achieved by composing or decomposing adjacent prefixes.
Solution¶
Upgrade the host Linux version to 4.11 or later. This step is beyond the scope of the Cilium guide.
Upgrading DNS Polling deployments to DNS Proxy (preferred)¶
In cilium versions 1.2 and 1.3 DNS Polling was automatically used to
obtain IP information for use in toFQDNs.matchName rules in DNS based
policies.
Cilium 1.4 and later have switched to a DNS Proxy scheme - the
DNS Polling behaviour may be enabled via the a CLI option - and expect a
pod to make a DNS request that can be intercepted. Existing pods may have
already-cached DNS lookups that the proxy cannot intercept and thus cilium will
block these on upgrade. New connections with DNS requests that can be
intercepted will be allowed per-policy without special action.
Cilium deployments already configured with DNS Proxy rules are not
impacted and will retain DNS data when restarted or upgraded.
Affected versions¶
- Cilium 1.2 and 1.3 when using DNS Polling with
toFQDNs.matchNamepolicy rules and upgrading to cilium 1.4.0 or later. - Cilium 1.4 or later that do not yet have L7 DNS Proxy (preferred) policy rules.
Mitigation¶
Deployments that require a seamless transition to DNS Proxy
may use Running a pre-flight DaemonSet to create a copy of DNS information on each cilium
node for use by the upgraded cilium-agent at startup. This data is used to
allow L3 connections (via toFQDNs.matchName and toFQDNs.matchPattern
rules) without a DNS request from pods.
Running a pre-flight DaemonSet accomplishes this via the --tofqdns-pre-cache CLI option,
which reads DNS cache data for use on startup.
Solution¶
DNS data obtained via polling must be recorded for use on startup and rules added to intercept DNS lookups. The steps are split into a section on seamlessly upgrading DNS Polling and then further beginning to intercept DNS data via a DNS Proxy.
Policy rules may be prepared to use the DNS Proxy before an
upgrade to 1.4. The new policy rule fields toFQDNs.matchPattern and
toPorts.rules.dns.matchName/matchPattern will be ignored by older cilium
versions and can be safely implemented prior to an upgrade.
The following example allows DNS access to kube-dns via the DNS Proxy and allows all DNS requests to kube-dns. For completeness,
toFQDNs rules are included for examples of the syntax for those L3 policies
as well. Existing toFQDNs rules do not need to be modified but will now use
IPs seen by DNS requests and allowed by the toFQDNs.matchPattern rule.
apiVersion: cilium.io/v2
kind: CiliumNetworkPolicy
metadata:
name: "tofqdn-dns-visibility"
spec:
endpointSelector:
matchLabels:
any:org: alliance
egress:
- toEndpoints:
- matchLabels:
"k8s:io.kubernetes.pod.namespace": kube-system
"k8s:k8s-app": kube-dns
toPorts:
- ports:
- port: "53"
protocol: ANY
rules:
dns:
- matchPattern: "*"
- toFQDNs:
- matchName: "cilium.io"
- matchName: "sub.cilium.io"
[
{
"endpointSelector": {
"matchLabels": {
"app": "test-app"
}
},
"egress": [
{
"toEndpoints": [
{
"matchLabels": {
"app-type": "dns"
}
}
],
"toPorts": [
{
"ports": [
{
"port": "53",
"protocol": "ANY"
}
],
"rules": {
"dns": [
{ "matchPattern": "*" }
]
}
}
]
},
{
"toFQDNs": [
{ "matchName": "cilium.io" },
{ "matchName": "sub.cilium.io" }
]
}
]
}
]
Upgrade steps - DNS Polling¶
- Set the
tofqdns-enable-pollerfield to true in the cilium ConfigMap used in the upgrade. Alternatively, pass--tofqdns-enable-poller=trueto the upgraded cilium-agent. - Add
tofqdns-pre-cache: "/var/run/cilium/dns-precache-upgrade.json"to the ConfigMap. Alternatively, pass--tofqdns-pre-cache="/var/run/cilium/dns-precache-upgrade.json"to cilium-agent. - Deploy the cilium Running a pre-flight DaemonSet helper. This will download the cilium
container image and also create DNS pre-cache data at
/var/run/cilium/dns-precache-upgrade.json. This data will have a TTL of 1 week. - Deploy the new cilium DaemonSet
- (optional) Remove
tofqdns-pre-cache: "/var/run/cilium/dns-precache-upgrade.json"from the cilium ConfigMap. The data will automatically age-out after 1 week.
Conversion steps - DNS Proxy (preferred)¶
- Update existing policies to intercept DNS requests. See DNS Policy and IP Discovery or the example above
- Allow pods to make DNS requests to populate the cilium-agent cache. To check
which exact queries are in the DNS cache and when they will expire use
cilium fqdn cache list - Set the
tofqdns-enable-pollerfield to false in the cilium ConfigMap - Restart the cilium pods with the new ConfigMap. They will restore Endpoint policy with DNS information from intercepted DNS requests stored in the cache
Network Policy¶
This chapter documents the policy language used to configure network policies in Cilium. Security policies can be specified and imported via the following mechanisms:
- Using Kubernetes NetworkPolicy and CiliumNetworkPolicy resources. See the section Network Policy for more details. In this mode, Kubernetes will automatically distribute the policies to all agents.
- Directly imported into the agent via CLI or API Reference of the agent. This method does not automatically distribute policies to all agents. It is in the responsibility of the user to import the policy in all required agents.
New in version future: Use of the KVstore to distribute security policies is on the roadmap but has not been implemented yet.
Policy Enforcement Modes¶
The configuration of the Cilium agent and the Cilium Network Policy determines whether an endpoint accepts traffic from a source or not. The agent can be put into the following three policy enforcement modes:
- default
This is the default behavior for policy enforcement when Cilium is launched without any specified value for the policy enforcement configuration. The following rules apply:
- If any rule selects an Endpoint and the rule has an ingress section, the endpoint goes into default deny at ingress.
- If any rule selects an Endpoint and the rule has an egress section, the endpoint goes into default deny at egress.
This means that endpoints will start without any restrictions and as soon as a rule restricts their ability to receive traffic on ingress or to transmit traffic on egress, then the endpoint goes into whitelisting mode and all traffic must be explicitly allowed.
- always
- With always mode, policy enforcement is enabled on all endpoints even if no rules select specific endpoints.
- never
- With never mode, policy enforcement is disabled on all endpoints, even if rules do select specific endpoints. In other words, all traffic is allowed from any source (on ingress) or destination (on egress).
To configure the policy enforcement mode at runtime for all endpoints managed by a Cilium agent, use:
$ cilium config PolicyEnforcement={default,always,never}
If you want to configure the policy enforcement mode at start-time for a particular agent, provide the following flag when launching the Cilium daemon:
$ cilium-agent --enable-policy={default,always,never} [...]
Similarly, you can enable the policy enforcement mode across a Kubernetes cluster by including the parameter above in the Cilium DaemonSet.
- name: CILIUM_ENABLE_POLICY
value: always
Rule Basics¶
All policy rules are based upon a whitelist model, that is, each rule in the policy allows traffic that matches the rule. If two rules exist, and one would match a broader set of traffic, then all traffic matching the broader rule will be allowed. If there is an intersection between two or more rules, then traffic matching the union of those rules will be allowed. Finally, if traffic does not match any of the rules, it will be dropped pursuant to the Policy Enforcement Modes.
Policy rules share a common base type which specifies which endpoints the rule applies to and common metadata to identify the rule. Each rule is split into an ingress section and an egress section. The ingress section contains the rules which must be applied to traffic entering the endpoint, and the egress section contains rules applied to traffic coming from the endpoint matching the endpoint selector. Either ingress, egress, or both can be provided. If both ingress and egress are omitted, the rule has no effect.
type Rule struct {
// EndpointSelector selects all endpoints which should be subject to
// this rule. Cannot be empty.
EndpointSelector EndpointSelector `json:"endpointSelector"`
// Ingress is a list of IngressRule which are enforced at ingress.
// If omitted or empty, this rule does not apply at ingress.
//
// +optional
Ingress []IngressRule `json:"ingress,omitempty"`
// Egress is a list of EgressRule which are enforced at egress.
// If omitted or empty, this rule does not apply at egress.
//
// +optional
Egress []EgressRule `json:"egress,omitempty"`
// Labels is a list of optional strings which can be used to
// re-identify the rule or to store metadata. It is possible to lookup
// or delete strings based on labels. Labels are not required to be
// unique, multiple rules can have overlapping or identical labels.
//
// +optional
Labels labels.LabelArray `json:"labels,omitempty"`
// Description is a free form string, it can be used by the creator of
// the rule to store human readable explanation of the purpose of this
// rule. Rules cannot be identified by comment.
//
// +optional
Description string `json:"description,omitempty"`
}
- endpointSelector
- Selects the endpoints which the policy rules apply to. The policy rules will be applied to all endpoints which match the labels specified in the Endpoint Selector. See the Endpoint Selector section for additional details.
- ingress
- List of rules which must apply at ingress of the endpoint, i.e. to all network packets which are entering the endpoint.
- egress
- List of rules which must apply at egress of the endpoint, i.e. to all network packets which are leaving the endpoint.
- labels
- Labels are used to identify the rule. Rules can be listed and deleted by
labels. Policy rules which are imported via kubernetes
automatically get the label
io.cilium.k8s.policy.name=NAMEassigned whereNAMEcorresponds to the name specified in the NetworkPolicy or CiliumNetworkPolicy resource. - description
- Description is a string which is not interpreted by Cilium. It can be used to describe the intent and scope of the rule in a human readable form.
Endpoint Selector¶
The Endpoint Selector is based on the Kubernetes LabelSelector. It is called Endpoint Selector because it only applies to labels associated with Endpoint.
Layer 3 Examples¶
The layer 3 policy establishes the base connectivity rules regarding which endpoints can talk to each other. Layer 3 policies can be specified using the following methods:
- Labels Based: This is used to describe the relationship if both endpoints are managed by Cilium and are thus assigned labels. The big advantage of this method is that IP addresses are not encoded into the policies and the policy is completely decoupled from the addressing.
- Services based: This is an intermediate form between Labels and CIDR and makes use of the services concept in the orchestration system. A good example of this is the Kubernetes concept of Service endpoints which are automatically maintained to contain all backend IP addresses of a service. This allows to avoid hardcoding IP addresses into the policy even if the destination endpoint is not controlled by Cilium.
- Entities Based: Entities are used to describe remote peers which can be categorized without knowing their IP addresses. This includes connectivity to the local host serving the endpoints or all connectivity to outside of the cluster.
- IP/CIDR based: This is used to describe the relationship to or from external services if the remote peer is not an endpoint. This requires to hardcode either IP addresses or subnets into the policies. This construct should be used as a last resort as it requires stable IP or subnet assignments.
- DNS based: Selects remote, non-cluster, peers using DNS names converted to IPs via DNS lookups. It shares all limitations of the IP/CIDR based rules above. DNS information is acquired by routing DNS traffic via a proxy, or polling for listed DNS targets. DNS TTLs are respected.
Labels Based¶
Label-based L3 policy is used to establish policy between endpoints inside the cluster managed by Cilium. Label-based L3 policies are defined by using an Endpoint Selector inside a rule to choose what kind of traffic that can be received (on ingress), or sent (on egress). An empty Endpoint Selector allows all traffic. The examples below demonstrate this in further detail.
Note
Kubernetes: See section Namespaces for details on how the Endpoint Selector applies in a Kubernetes environment with regard to namespaces.
Ingress¶
An endpoint is allowed to receive traffic from another endpoint if at least one
ingress rule exists which selects the destination endpoint with the
Endpoint Selector in the endpointSelector field. To restrict traffic upon
ingress to the selected endpoint, the rule selects the source endpoint with the
Endpoint Selector in the fromEndpoints field.
Simple Ingress Allow¶
The following example illustrates how to use a simple ingress rule to allow
communication from endpoints with the label role=frontend to endpoints with
the label role=backend.
apiVersion: "cilium.io/v2"
kind: CiliumNetworkPolicy
metadata:
name: "l3-rule"
spec:
endpointSelector:
matchLabels:
role: backend
ingress:
- fromEndpoints:
- matchLabels:
role: frontend
[{
"labels": [{"key": "name", "value": "l3-rule"}],
"endpointSelector": {"matchLabels": {"role":"backend"}},
"ingress": [{
"fromEndpoints": [
{"matchLabels":{"role":"frontend"}}
]
}]
}]
Ingress Allow All¶
An empty Endpoint Selector will select all endpoints, thus writing a rule that will allow all ingress traffic to an endpoint may be done as follows:
apiVersion: "cilium.io/v2"
kind: CiliumNetworkPolicy
metadata:
name: "allow-all-to-victim"
spec:
endpointSelector:
matchLabels:
role: victim
ingress:
- fromEndpoints:
- {}
[{
"labels": [{"key": "name", "value": "allow-all-to-victim"}],
"endpointSelector": {"matchLabels": {"role":"victim"}},
"ingress": [{
"fromEndpoints": [
{"matchLabels":{}}
]
}]
}]
Note that while the above examples allow all ingress traffic to an endpoint, this does not mean that all endpoints are allowed to send traffic to this endpoint per their policies. In other words, policy must be configured on both sides (sender and receiver).
Egress¶
An endpoint is allowed to send traffic to another endpoint if at least one
egress rule exists which selects the destination endpoint with the
Endpoint Selector in the endpointSelector field. To restrict traffic upon
egress to the selected endpoint, the rule selects the destination endpoint with
the Endpoint Selector in the toEndpoints field.
Simple Egress Allow¶
The following example illustrates how to use a simple egress rule to allow
communication to endpoints with the label role=backend from endpoints with
the label role=frontend.
apiVersion: "cilium.io/v2"
kind: CiliumNetworkPolicy
metadata:
name: "l3-egress-rule"
spec:
endpointSelector:
matchLabels:
role: frontend
egress:
- toEndpoints:
- matchLabels:
role: backend
[{
"labels": [{"key": "name", "value": "l3-egress-rule"}],
"endpointSelector": {"matchLabels": {"role":"frontend"}},
"egress": [{
"toEndpoints": [
{"matchLabels":{"role":"backend"}}
]
}]
}]
Egress Allow All¶
An empty Endpoint Selector will select all endpoints, thus writing a rule that will allow all egress traffic from an endpoint may be done as follows:
apiVersion: "cilium.io/v2"
kind: CiliumNetworkPolicy
metadata:
name: "allow-all-from-frontend"
spec:
endpointSelector:
matchLabels:
role: frontend
egress:
- toEndpoints:
- {}
[{
"labels": [{"key": "name", "value": "allow-all-from-frontend"}],
"endpointSelector": {"matchLabels": {"role":"frontend"}},
"egress": [{
"toEndpoints": [
{"matchLabels":{}}
]
}]
}]
Note that while the above examples allow all egress traffic from an endpoint, the receivers of the egress traffic may have ingress rules that deny the traffic. In other words, policy must be configured on both sides (sender and receiver).
Ingress/Egress Default Deny¶
An endpoint can be put into the default deny mode at ingress or egress if a rule selects the endpoint and contains the respective rule section ingress or egress.
Note
Any rule selecting the endpoint will have this effect, this example illustrates how to put an endpoint into default deny mode without whitelisting other peers at the same time.
apiVersion: "cilium.io/v2"
kind: CiliumNetworkPolicy
metadata:
name: "deny-all-egress"
spec:
endpointSelector:
matchLabels:
role: restricted
egress:
- {}
[{
"labels": [{"key": "name", "value": "deny-all-egress"}],
"endpointSelector": {"matchLabels": {"role":"restricted"}},
"egress": [{}]
}]
Additional Label Requirements¶
It is often required to apply the principle of separation of concern when defining policies. For this reason, an additional construct exists which allows to establish base requirements for any connectivity to happen.
For this purpose, the fromRequires field can be used to establish label
requirements which serve as a foundation for any fromEndpoints
relationship. fromRequires is a list of additional constraints which must
be met in order for the selected endpoints to be reachable. These additional
constraints do not grant access privileges by themselves, so to allow traffic
there must also be rules which match fromEndpoints. The same applies for
egress policies, with toRequires and toEndpoints.
The purpose of this rule is to allow establishing base requirements such as, any
endpoint in env=prod can only be accessed if the source endpoint also carries
the label env=prod.
This example shows how to require every endpoint with the label env=prod to
be only accessible if the source endpoint also has the label env=prod.
apiVersion: "cilium.io/v2"
kind: CiliumNetworkPolicy
description: "For endpoints with env=prod, only allow if source also has label env=prod"
metadata:
name: "requires-rule"
specs:
- endpointSelector:
matchLabels:
env: prod
ingress:
- fromRequires:
- matchLabels:
env: prod
[{
"labels": [{"key": "name", "value": "requires-rule"}],
"endpointSelector": {"matchLabels": {"env":"prod"}},
"ingress": [{
"fromRequires": [
{"matchLabels":{"env":"prod"}}
]
}]
}]
Services based¶
Services running in your cluster can be whitelisted in Egress rules. Currently Kubernetes Services without a Selector are supported when defined by their name and namespace or label selector. Future versions of Cilium will support specifying non-Kubernetes services and Kubernetes services which are backed by pods.
This example shows how to allow all endpoints with the label id=app2
to talk to all endpoints of kubernetes service myservice in kubernetes
namespace default.
Note
These rules will only take effect on Kubernetes services without a selector.
apiVersion: "cilium.io/v2"
kind: CiliumNetworkPolicy
metadata:
name: "service-rule"
spec:
endpointSelector:
matchLabels:
id: app2
egress:
- toServices:
- k8sService:
serviceName: myservice
namespace: default
[{
"labels": [{"key": "name", "value": "service-rule"}],
"endpointSelector": {
"matchLabels": {
"id": "app2"
}
},
"egress": [
{
"toServices": [
{
"k8sService": {
"serviceName": "myservice",
"namespace": "default"
}
}
]
}
]
}]
This example shows how to allow all endpoints with the label id=app2
to talk to all endpoints of all kubernetes headless services which
have head:none set as the label.
apiVersion: "cilium.io/v2"
kind: CiliumNetworkPolicy
metadata:
name: "service-labels-rule"
spec:
endpointSelector:
matchLabels:
id: app2
egress:
- toServices:
- k8sServiceSelector:
selector:
matchLabels:
head: none
[{
"labels": [{"key": "name", "value": "service-labels-rule"}],
"endpointSelector": {
"matchLabels": {
"id": "app2"
}
},
"egress": [
{
"toServices": [
{
"k8sServiceSelector": {
"selector": {
"matchLabels": {
"head": "none"
}
}
}
}
]
}
]
}
]
Entities Based¶
fromEntities is used to describe the entities that can access the selected
endpoints. toEntities is used to describe the entities that can be accessed
by the selected endpoints.
The following entities are defined:
- host
- The host entity includes all cluster nodes. This also includes all containers running in host networking mode.
- cluster
- Cluster is the logical group of all network endpoints inside of the local cluster. This includes all Cilium-managed endpoints of the local cluster. It also includes the host entity to cover host networking containers as well as the init entity to include endpoints currently being bootstrapped.
- init
- The init entity contains all endpoints in bootstrap phase for which the security identity has not been resolved yet. See section Endpoint Lifecycle for details.
- world
- The world entity corresponds to all endpoints outside of the cluster. Allowing to world is identical to allowing to CIDR 0/0. An alternative to allowing from and to world is to define fine grained DNS or CIDR based policies.
- all
- The all entity represents the combination of all known clusters as well world and whitelists all communication.
New in version future: Allowing users to define custom identities is on the roadmap but has not been implemented yet.
Access to/from local host¶
Allow all endpoints with the label env=dev to access the host that is
serving the particular endpoint.
Note
Kubernetes will automatically allow all communication from and to the
local host of all local endpoints. You can run the agent with the
option --allow-localhost=policy to disable this behavior which
will give you control over this via policy.
apiVersion: "cilium.io/v2"
kind: CiliumNetworkPolicy
metadata:
name: "dev-to-host"
spec:
endpointSelector:
matchLabels:
env: dev
egress:
- toEntities:
- host
[{
"labels": [{"key": "name", "value": "dev-to-host"}],
"endpointSelector": {"matchLabels": {"env":"dev"}},
"egress": [{
"toEntities": ["host"]
}]
}]
Access to/from outside cluster¶
This example shows how to enable access from outside of the cluster to all
endpoints that have the label role=public.
apiVersion: "cilium.io/v2"
kind: CiliumNetworkPolicy
metadata:
name: "from-world-to-role-public"
spec:
endpointSelector:
matchLabels:
role: public
ingress:
- fromEntities:
- world
[{
"labels": [{"key": "name", "value":"from-world-to-role-public"}],
"endpointSelector": {"matchLabels": {"role":"public"}},
"ingress": [{
"fromEntities": ["world"]
}]
}]
IP/CIDR based¶
CIDR policies are used to define policies to and from endpoints which are not managed by Cilium and thus do not have labels associated with them. These are typically external services, VMs or metal machines running in particular subnets. CIDR policy can also be used to limit access to external services, for example to limit external access to a particular IP range. CIDR policies can be applied at ingress or egress.
CIDR rules apply if Cilium cannot map the source or destination to an identity derived from endpoint labels, ie the Special Identities. For example, CIDR rules will apply to traffic where one side of the connection is:
- A network endpoint outside the cluster
- The host network namespace where the pod is running.
- Within the cluster prefix but the IP’s networking is not provided by Cilium.
Note
When running Cilium on Linux 4.10 or earlier, there are Restrictions on unique prefix lengths for CIDR policy rules.
Ingress¶
- fromCIDR
- List of source prefixes/CIDRs that are allowed to talk to all endpoints
selected by the
endpointSelector. - fromCIDRSet
- List of source prefixes/CIDRs that are allowed to talk to all endpoints
selected by the
endpointSelector, along with an optional list of prefixes/CIDRs per source prefix/CIDR that are subnets of the source prefix/CIDR from which communication is not allowed.
Egress¶
- toCIDR
- List of destination prefixes/CIDRs that endpoints selected by
endpointSelectorare allowed to talk to. Note that endpoints which are selected by afromEndpointsare automatically allowed to talk to their respective destination endpoints. - toCIDRSet
- List of destination prefixes/CIDRs that are allowed to talk to all endpoints
selected by the
endpointSelector, along with an optional list of prefixes/CIDRs per source prefix/CIDR that are subnets of the destination prefix/CIDR to which communication is not allowed.
Allow to external CIDR block¶
This example shows how to allow all endpoints with the label app=myService
to talk to the external IP 20.1.1.1, as well as the CIDR prefix 10.0.0.0/8,
but not CIDR prefix 10.96.0.0/12
apiVersion: "cilium.io/v2"
kind: CiliumNetworkPolicy
metadata:
name: "cidr-rule"
spec:
endpointSelector:
matchLabels:
app: myService
egress:
- toCIDR:
- 20.1.1.1/32
- toCIDRSet:
- cidr: 10.0.0.0/8
except:
- 10.96.0.0/12
[{
"labels": [{"key": "name", "value": "cidr-rule"}],
"endpointSelector": {"matchLabels":{"app":"myService"}},
"egress": [{
"toCIDR": [
"20.1.1.1/32"
]
}, {
"toCIDRSet": [{
"cidr": "10.0.0.0/8",
"except": [
"10.96.0.0/12"
]}
]
}]
}]
DNS based¶
DNS policies are used to define Layer 3 policies to endpoints that are not managed by cilium, but have DNS queryable domain names. The IP addresses provided in DNS responses are allowed by Cilium in a similar manner to IPs in CIDR based policies. They are an alternative when the remote IPs may change or are not know a priori, or when DNS is more convenient. To enforce policy on DNS requests themselves, see Layer 7 Examples.
IP information is captured from DNS responses per-Endpoint via a DNS Proxy
or DNS Polling. An L3 CIDR based rule is generated for every toFQDNs
rule and applies to the same endpoints. The IP information is selected for
insertion by matchName or matchPattern rules, and is collected from all
DNS responses seen by Cilium on the node. Multiple selectors may be included in
a single egress rule. See Obtaining DNS Data for use by toFQDNs for information on
collecting this IP data.
toFQDNs egress rules cannot contain any other L3 rules, such as
toEndpoints (under Labels Based) and toCIDRs (under CIDR Based).
They may contain L4/L7 rules, such as toPorts (see Layer 4 Examples)
with, optionally, HTTP and Kafka sections (see Layer 7 Examples).
Note
DNS based rules are intended for external connections and behave similarly to CIDR based rules. See Services based and Labels based for cluster-internal traffic.
IPs to be allowed are selected via:
toFQDNs.matchName- Inserts IPs of domains that match
matchNameexactly. Multiple distinct names may be included in separatematchNameentries and IPs for domains that match anymatchNamewill be inserted. toFQDNs.matchPatternInserts IPs of domains that match the pattern in
matchPattern, accounting for wildcards. Patterns are composed of literal characters that that are allowed in domain names: a-z, 0-9,.and-.*is allowed as a wildcard with a number of convenience behaviors:*within a domain allows 0 or more valid DNS characters, except for the.separator.*.cilium.iowill matchsub.cilium.iobut notcilium.io.part*ial.comwill matchpartial.comandpart-extra-ial.com.*alone matches all names, and inserts all cached DNS IPs into this rule.
Note
DNS Polling will not poll matchPattern entries even if they
are literal DNS names.
Example¶
apiVersion: "cilium.io/v2"
kind: CiliumNetworkPolicy
metadata:
name: "to-fqdn"
spec:
endpointSelector:
matchLabels:
app: test-app
egress:
- toEndpoints:
- matchLabels:
"k8s:io.kubernetes.pod.namespace": kube-system
"k8s:k8s-app": kube-dns
toPorts:
- ports:
- port: "53"
protocol: ANY
rules:
dns:
- matchPattern: "*"
- toFQDNs:
- matchName: "my-remote-service.com"
[
{
"endpointSelector": {
"matchLabels": {
"app": "test-app"
}
},
"egress": [
{
"toEndpoints": [
{
"matchLabels": {
"app-type": "dns"
}
}
],
"toPorts": [
{
"ports": [
{
"port": "53",
"protocol": "ANY"
}
],
"rules": {
"dns": [
{ "matchPattern": "*" }
]
}
}
]
},
{
"toFQDNs": [
{
"matchName": "my-remote-service.com"
}
]
}
]
}
]
Managing Long-Lived Connections & Minimum DNS Cache Times¶
Often, an application may keep a connection open for longer than the configured DNS TTL. Without further DNS queries the remote IP used in the long-lived connection may expire out of the DNS cache. When this occurs, existing connections will become disallowed by policy and will be blocked. In cases where an application retries the connection, a new DNS query is issued and the IP is added to the policy.
A minimum TTL is used to ensure a lower bound to DNS data expiration, and DNS
data in the Cilium DNS cache will not expire sooner than this minimum. It
can be configured with the --tofqdns-min-ttl CLI option. The value is in
integer seconds and must be 1 or more. The default is 1 week, or 1 hour when
DNS Polling is enabled.
Some care needs to be taken when setting --tofqdns-min-ttl with DNS data
that returns many distinct IPs over time. A long TTL will keep each IP cached
long after the related connections may have terminated. Large numbers of IPs
have corresponding Security Identities and too many may slow down Cilium policy
regeneration. This can be especially pronounced when using DNS Polling to
obtain DNS data. In such cases a shorter minimum TTL is recommended, as
DNS Polling will recover up-do-date IPs regularly.
Note
It is recommended that --tofqdns-min-ttl be set to the minimum
time a connection must be maintained.
Managing Short-Lived Connections & Maximum IPs per FQDN/endpoint¶
The minimal TTL for DNS entries in the cache is deliberately long with 1 week
per default. This is done to accommodate long-lived, persistent connections. On
the other end of the spectrum are workloads which perform short-lived
connections in repetition to FQDNs which are backed by a large number of IP
addresses (e.g. AWS S3). Such workloads can grow the number of IPs mapping to an
FQDN quickly. In order to limit the number of IP addresses that map a particular
FQDN, each FQDN per endpoint has a max capacity of IPs that are being maintained
(default: 50). Once the capacity is exceeded, the oldest entries are
automatically expired from the cache. This capacity can be changed using the
--tofqdns-max-ip-per-hostname option.
Layer 4 Examples¶
Limit ingress/egress ports¶
Layer 4 policy can be specified in addition to layer 3 policies or independently. It restricts the ability of an endpoint to emit and/or receive packets on a particular port using a particular protocol. If no layer 4 policy is specified for an endpoint, the endpoint is allowed to send and receive on all layer 4 ports and protocols including ICMP. If any layer 4 policy is specified, then ICMP will be blocked unless it’s related to a connection that is otherwise allowed by the policy. Layer 4 policies apply to ports after service port mapping has been applied.
Layer 4 policy can be specified at both ingress and egress using the
toPorts field. The toPorts field takes a PortProtocol structure
which is defined as follows:
// PortProtocol specifies an L4 port with an optional transport protocol
type PortProtocol struct {
// Port is an L4 port number. For now the string will be strictly
// parsed as a single uint16. In the future, this field may support
// ranges in the form "1024-2048
Port string `json:"port"`
// Protocol is the L4 protocol. If omitted or empty, any protocol
// matches. Accepted values: "TCP", "UDP", ""/"ANY"
//
// Matching on ICMP is not supported.
//
// +optional
Protocol string `json:"protocol,omitempty"`
}
Example (L4)¶
The following rule limits all endpoints with the label app=myService to
only be able to emit packets using TCP on port 80, to any layer 3 destination:
apiVersion: "cilium.io/v2"
kind: CiliumNetworkPolicy
metadata:
name: "l4-rule"
spec:
endpointSelector:
matchLabels:
app: myService
egress:
- toPorts:
- ports:
- port: "80"
protocol: TCP
[{
"labels": [{"key": "name", "value": "l4-rule"}],
"endpointSelector": {"matchLabels":{"app":"myService"}},
"egress": [{
"toPorts": [
{"ports":[ {"port": "80", "protocol": "TCP"}]}
]
}]
}]
Labels-dependent Layer 4 rule¶
This example enables all endpoints with the label role=frontend to
communicate with all endpoints with the label role=backend, but they must
communicate using TCP on port 80. Endpoints with other labels will not be
able to communicate with the endpoints with the label role=backend, and
endpoints with the label role=frontend will not be able to communicate with
role=backend on ports other than 80.
apiVersion: "cilium.io/v2"
kind: CiliumNetworkPolicy
metadata:
name: "l4-rule"
spec:
endpointSelector:
matchLabels:
role: backend
ingress:
- fromEndpoints:
- matchLabels:
role: frontend
toPorts:
- ports:
- port: "80"
protocol: TCP
[{
"labels": [{"key": "name", "value": "l4-rule"}],
"endpointSelector": {"matchLabels":{"role":"backend"}},
"ingress": [{
"fromEndpoints": [
{"matchLabels":{"role":"frontend"}}
],
"toPorts": [
{"ports":[ {"port": "80", "protocol": "TCP"}]}
]
}]
}]
CIDR-dependent Layer 4 Rule¶
This example enables all endpoints with the label role=crawler to
communicate with all remote destinations inside the CIDR 192.0.2.0/24, but
they must communicate using TCP on port 80. The policy does not allow Endpoints
without the label role=crawler to communicate with destinations in the CIDR
192.0.2.0/24. Furthermore, endpoints with the label role=crawler will
not be able to communicate with destinations in the CIDR 192.0.2.0/24 on
ports other than port 80.
apiVersion: "cilium.io/v2"
kind: CiliumNetworkPolicy
metadata:
name: "cidr-l4-rule"
spec:
endpointSelector:
matchLabels:
role: crawler
egress:
- toCIDR:
- 192.0.2.0/24
toPorts:
- ports:
- port: "80"
protocol: TCP
[{
"labels": [{"key": "name", "value": "cidr-l4-rule"}],
"endpointSelector": {"matchLabels":{"role":"crawler"}},
"egress": [{
"toCIDR": [
"192.0.2.0/24"
],
"toPorts": [
{"ports":[ {"port": "80", "protocol": "TCP"}]}
]
}]
}]
Layer 7 Examples¶
Layer 7 policy rules are embedded into Layer 4 Examples rules and can be specified
for ingress and egress. L7Rules structure is a base type containing an
enumeration of protocol specific fields.
// L7Rules is a union of port level rule types. Mixing of different port
// level rule types is disallowed, so exactly one of the following must be set.
// If none are specified, then no additional port level rules are applied.
type L7Rules struct {
// HTTP specific rules.
//
// +optional
HTTP []PortRuleHTTP `json:"http,omitempty"`
// Kafka-specific rules.
//
// +optional
Kafka []PortRuleKafka `json:"kafka,omitempty"`
// DNS-specific rules.
//
// +optional
DNS []PortRuleDNS `json:"dns,omitempty"`
}
The structure is implemented as a union, i.e. only one member field can be used
per port. If multiple toPorts rules with identical PortProtocol select
an overlapping list of endpoints, then the layer 7 rules are combined together
if they are of the same type. If the type differs, the policy is rejected.
Each member consists of a list of application protocol rules. A layer 7 request is permitted if at least one of the rules matches. If no rules are specified, then all traffic is permitted.
If a layer 4 rule is specified in the policy, and a similar layer 4 rule with layer 7 rules is also specified, then the layer 7 portions of the latter rule will have no effect.
Note
Unlike layer 3 and layer 4 policies, violation of layer 7 rules does not result in packet drops. Instead, if possible, an application protocol specific access denied message is crafted and returned, e.g. an HTTP 403 access denied is sent back for HTTP requests which violate the policy, or a DNS REFUSED response for DNS requests.
Note
There is currently a max limit of 40 ports with layer 7 policies per endpoint. This might change in the future when support for ranges is added.
HTTP¶
The following fields can be matched on:
- Path
- Path is an extended POSIX regex matched against the path of a request.
Currently it can contain characters disallowed from the conventional “path”
part of a URL as defined by RFC 3986. Paths must begin with a
/. If omitted or empty, all paths are all allowed. - Method
- Method is an extended POSIX regex matched against the method of a request,
e.g.
GET,POST,PUT,PATCH,DELETE, … If omitted or empty, all methods are allowed. - Host
- Host is an extended POSIX regex matched against the host header of a request,
e.g.
foo.com. If omitted or empty, the value of the host header is ignored. - Headers
- Headers is a list of HTTP headers which must be present in the request. If omitted or empty, requests are allowed regardless of headers present.
Allow GET /public¶
The following example allows GET requests to the URL /public to be
allowed to endpoints with the labels env:prod, but requests to any other
URL, or using another method, will be rejected. Requests on ports other than
port 80 will be dropped.
apiVersion: "cilium.io/v2"
kind: CiliumNetworkPolicy
description: "Allow HTTP GET /public from env=prod to app=service"
metadata:
name: "rule1"
spec:
endpointSelector:
matchLabels:
app: service
ingress:
- fromEndpoints:
- matchLabels:
env: prod
toPorts:
- ports:
- port: "80"
protocol: TCP
rules:
http:
- method: "GET"
path: "/public"
[{
"labels": [{"key": "name", "value": "rule1"}],
"endpointSelector": {"matchLabels": {"app": "service"}},
"ingress": [{
"fromEndpoints": [
{"matchLabels": {"env": "prod"}}
]},{
"toPorts": [{
"ports": [
{"port": "80", "protocol": "TCP"}
],
"rules": {
"http": [
{
"method": "GET",
"path": "/public"
}
]
}
}]
}]
}]
All GET /path1 and PUT /path2 when header set¶
The following example limits all endpoints which carry the labels
app=myService to only be able to receive packets on port 80 using TCP.
While communicating on this port, the only API endpoints allowed will be GET
/path1 and PUT /path2 with the HTTP header X-My_header set to
true:
apiVersion: "cilium.io/v2"
kind: CiliumNetworkPolicy
metadata:
name: "l7-rule"
spec:
endpointSelector:
matchLabels:
app: myService
ingress:
- toPorts:
- ports:
- port: '80'
protocol: TCP
rules:
http:
- method: GET
path: "/path1$"
- method: PUT
path: "/path2$"
headers:
- 'X-My-Header: true'
[{
"labels": [{"key": "name", "value": "l7-rule"}],
"endpointSelector": {"matchLabels":{"app":"myService"}},
"ingress": [{
"toPorts": [{
"ports": [
{"port": "80", "protocol": "TCP"}
],
"rules": {
"http": [
{
"method": "GET",
"path": "/path1$"
},{
"method": "PUT",
"path": "/path2$",
"headers": ["X-My-Header: true"]
}
]
}
}]
}]
}]
Kafka (beta)¶
Note
Kafka support is currently in beta phase.
PortRuleKafka is a list of Kafka protocol constraints. All fields are optional, if all fields are empty or missing, the rule will match all Kafka messages. There are two ways to specify the Kafka rules. We can choose to specify a high-level “produce” or “consume” role to a topic or choose to specify more low-level Kafka protocol specific apiKeys. Writing rules based on Kafka roles is easier and covers most common use cases, however if more granularity is needed then users can alternatively write rules using specific apiKeys.
The following fields can be matched on:
- Role
Role is a case-insensitive string which describes a group of API keys necessary to perform certain higher-level Kafka operations such as “produce” or “consume”. A Role automatically expands into all APIKeys required to perform the specified higher-level operation. The following roles are supported:
- “produce”: Allow producing to the topics specified in the rule.
- “consume”: Allow consuming from the topics specified in the rule.
This field is incompatible with the APIKey field, i.e APIKey and Role cannot both be specified in the same rule. If omitted or empty, and if APIKey is not specified, then all keys are allowed.
- APIKey
- APIKey is a case-insensitive string matched against the key of a request, for example “produce”, “fetch”, “createtopic”, “deletetopic”. For a more extensive list, see the Kafka protocol reference. This field is incompatible with the Role field.
- APIVersion
- APIVersion is the version matched against the api version of the Kafka message. If set, it must be a string representing a positive integer. If omitted or empty, all versions are allowed.
- ClientID
ClientID is the client identifier as provided in the request.
From Kafka protocol documentation: This is a user supplied identifier for the client application. The user can use any identifier they like and it will be used when logging errors, monitoring aggregates, etc. For example, one might want to monitor not just the requests per second overall, but the number coming from each client application (each of which could reside on multiple servers). This id acts as a logical grouping across all requests from a particular client.
If omitted or empty, all client identifiers are allowed.
- Topic
Topic is the topic name contained in the message. If a Kafka request contains multiple topics, then all topics in the message must be allowed by the policy or the message will be rejected.
This constraint is ignored if the matched request message type does not contain any topic. The maximum length of the Topic is 249 characters, which must be either
a-z,A-Z,0-9,-,.or_.If omitted or empty, all topics are allowed.
Allow producing to topic empire-announce using Role¶
apiVersion: "cilium.io/v2"
kind: CiliumNetworkPolicy
description: "enable empire-hq to produce to empire-announce and deathstar-plans"
metadata:
name: "rule1"
spec:
endpointSelector:
matchLabels:
app: kafka
ingress:
- fromEndpoints:
- matchLabels:
app: empire-hq
toPorts:
- ports:
- port: "9092"
protocol: TCP
rules:
kafka:
- role: "produce"
topic: "deathstar-plans"
- role: "produce"
topic: "empire-announce"
[{
"labels": [{"key": "name", "value": "rule1"}],
"endpointSelector": {"matchLabels": {"app": "kafka"}},
"ingress": [{
"fromEndpoints": [
{"matchLabels": {"app": "empire-hq"}}
],
"toPorts": [{
"ports": [
{"port": "9092", "protocol": "TCP"}
],
"rules": {
"kafka": [
{"role": "produce","topic": "deathstar-plans"},
{"role": "produce", "topic": "empire-announce"}
]
}
}]
}]
}]
Allow producing to topic empire-announce using apiKeys¶
apiVersion: "cilium.io/v2"
kind: CiliumNetworkPolicy
description: "enable empire-hq to produce to empire-announce and deathstar-plans"
metadata:
name: "rule1"
spec:
endpointSelector:
matchLabels:
app: kafka
ingress:
- fromEndpoints:
- matchLabels:
app: empire-hq
toPorts:
- ports:
- port: "9092"
protocol: TCP
rules:
kafka:
- apiKey: "apiversions"
- apiKey: "metadata"
- apiKey: "produce"
topic: "deathstar-plans"
- apiKey: "produce"
topic: "empire-announce"
[{
"labels": [{"key": "name", "value": "rule1"}],
"endpointSelector": {"matchLabels": {"app": "kafka"}},
"ingress": [{
"fromEndpoints": [
{"matchLabels": {"app": "empire-hq"}}
],
"toPorts": [{
"ports": [
{"port": "9092", "protocol": "TCP"}
],
"rules": {
"kafka": [
{"apiKey": "apiversions"},
{"apiKey": "metadata"},
{"apiKey": "produce", "topic": "deathstar-plans"},
{"apiKey": "produce", "topic": "empire-announce"}
]
}
}]
}]
}]
DNS Policy and IP Discovery¶
Policy may be applied to DNS traffic, allowing or disallowing specific DNS
query names or patterns of names (other DNS fields, such as query type, are not
considered). This policy is effected via a DNS proxy, which is also used to
collect IPs used to populate L3 DNS based toFQDNs rules.
Note
While Layer 7 DNS policy can be applied without any other Layer 3 rules, the presence of a Layer 7 rule (with its Layer 3 and 4 components) will block other traffic.
DNS policy may be applied via:
matchName- Allows queries for domains that match
matchNameexactly. Multiple distinct names may be included in separatematchNameentries and queries for domains that match anymatchNamewill be allowed. matchPatternAllows queries for domains that match the pattern in
matchPattern, accounting for wildcards. Patterns are composed of literal characters that that are allowed in domain names: a-z, 0-9,.and-.*is allowed as a wildcard with a number of convenience behaviors:*within a domain allows 0 or more valid DNS characters, except for the.separator.*.cilium.iowill matchsub.cilium.iobut notcilium.io.part*ial.comwill matchpartial.comandpart-extra-ial.com.*alone matches all names, and inserts all IPs in DNS responses into the cilium-agent DNS cache.
In this example, L7 DNS policy allows queries for cilium.io and any
subdomains of cilium.io and api.cilium.io. No other DNS queries will be
allowed.
The separate L3 toFQDNs egress rule allows connections to any IPs returned
in DNS queries for cilium.io, sub.cilium.io, service1.api.cilium.io
and any matches of special*service.api.cilium.io, such as
special-region1-service.api.cilium.io but not
region1-service.api.cilium.io. DNS queries to anothersub.cilium.io are
allowed but connections to the returned IPs are not, as there is no L3
toFQDNs rule selecting them. L4 and L7 policy may also be applied (see
DNS based), restricting connections to TCP port 80 in this case.
apiVersion: cilium.io/v2
kind: CiliumNetworkPolicy
metadata:
name: "tofqdn-dns-visibility"
spec:
endpointSelector:
matchLabels:
any:org: alliance
egress:
- toEndpoints:
- matchLabels:
"k8s:io.kubernetes.pod.namespace": kube-system
"k8s:k8s-app": kube-dns
toPorts:
- ports:
- port: "53"
protocol: ANY
rules:
dns:
- matchName: "cilium.io"
- matchPattern: "*.cilium.io"
- matchPattern: "*.api.cilium.io"
- toFQDNs:
- matchName: "cilium.io"
- matchName: "sub.cilium.io"
- matchName: "service1.api.cilium.io"
- matchPattern: "special*service.api.cilium.io"
toPorts:
- ports:
- port: "80"
protocol: TCP
[
{
"endpointSelector": {
"matchLabels": {
"app": "test-app"
}
},
"egress": [
{
"toEndpoints": [
{
"matchLabels": {
"app-type": "dns"
}
}
],
"toPorts": [
{
"ports": [
{
"port": "53",
"protocol": "ANY"
}
],
"rules": {
"dns": [
{ "matchName": "cilium.io" },
{ "matchPattern": "*.cilium.io" },
{ "matchPattern": "*.api.cilium.io" }
]
}
}
]
},
{
"toFQDNs": [
{ "matchName": "cilium.io" },
{ "matchName": "sub.cilium.io" },
{ "matchName": "service1.api.cilium.io" },
{ "matchPattern": "special*service.api.cilium.io" }
]
}
]
}
]
Note
When applying DNS policy in kubernetes, queries for
service.namespace.svc.cluster.local. must be explicitly allowed
with matchPattern: *.*.svc.cluster.local..
Similarly, queries that rely on the DNS search list to complete the
FQDN must be allowed in their entirety. e.g. A query for
servicename that succeeds with
servicename.namespace.svc.cluster.local. must have the latter
allowed with matchName or matchPattern.
Obtaining DNS Data for use by toFQDNs¶
IPs are obtained via intercepting DNS requests with a proxy or DNS polling, and
matching names are inserted irrespective of how the data is obtained. These IPs
can be selected with toFQDN rules. DNS responses are cached within cilium
agent respecting TTL.
DNS Proxy (preferred)¶
A DNS Proxy intercepts egress DNS traffic and records IPs seen in the responses. This interception is, itself, a separate policy rule governing the DNS requests, and must be specified separately. For details on how to enforce policy on DNS requests and configuring the DNS proxy, see Layer 7 Examples.
Only IPs in intercepted DNS responses to an application will be allowed in the cilium policy rules. For a given domain name, IPs from responses to all pods managed by a Cilium instance are allowed by policy (respecting TTLs). This ensures that allowed IPs are consistent with those returned to applications. The DNS Proxy is the only method to allow IPs from responses allowed by wildcard L7 DNS
matchPatternrules for use intoFQDNsrules.The following example obtains DNS data by interception without blocking any DNS requests. It allows L3 connections to
cilium.io,sub.cilium.ioand any subdomains ofsub.cilium.io.
Note
The port number 53 shown in the examples is currently the only supported port number on which DNS requests can be proxied. This is the standard DNS port number, so it should work for most uses.
apiVersion: cilium.io/v2
kind: CiliumNetworkPolicy
metadata:
name: "tofqdn-dns-visibility"
spec:
endpointSelector:
matchLabels:
any:org: alliance
egress:
- toEndpoints:
- matchLabels:
"k8s:io.kubernetes.pod.namespace": kube-system
"k8s:k8s-app": kube-dns
toPorts:
- ports:
- port: "53"
protocol: ANY
rules:
dns:
- matchPattern: "*"
- toFQDNs:
- matchName: "cilium.io"
- matchName: "sub.cilium.io"
- matchPattern: "*.sub.cilium.io"
[
{
"endpointSelector": {
"matchLabels": {
"app": "test-app"
}
},
"egress": [
{
"toEndpoints": [
{
"matchLabels": {
"app-type": "dns"
}
}
],
"toPorts": [
{
"ports": [
{
"port": "53",
"protocol": "ANY"
}
],
"rules": {
"dns": [
{ "matchPattern": "*" }
]
}
}
]
},
{
"toFQDNs": [
{ "matchName": "cilium.io" },
{ "matchName": "sub.cilium.io" },
{ "matchPattern": "*.sub.cilium.io" }
]
}
]
}
]
DNS Polling¶
DNS Polling periodically issues a DNS lookup for each
matchNamefrom cilium-agent. The result is used to regenerate endpoint policy. Despite the name, thematchNamefield does not have to be a fully-qualified domain name. In cases where search domains are configured for cilium-agent, the DNS lookups from Cilium will not be qualified and will utilize the search list. Unqualified names must be matched as-is bymatchPatternin order to insert related IPs.DNS lookups are repeated with an interval of 5 seconds, and are made for A(IPv4) and AAAA(IPv6) addresses. Should a lookup fail, the most recent IP data is used instead. An IP change will trigger a regeneration of the Cilium policy for each endpoint and increment the per cilium-agent policy repository revision.
Polling may be enabled by the
--tofqdns-enable-pollercilium-agent CLI option. It is disabled by default.The DNS polling implementation is very limited. It may not behave as expected.
- The DNS polling is done from the cilium-agent process. This may result in different IPs being returned in the DNS response than those seen by an application.
- When using DNS Polling with DNS responses that return a new IP on every query, the IP being whitelisted may differ from the one used for connections by applications. This is because the application will make a DNS query independent from the poll.
- When DNS lookups return many distinct IPs over time, large values of
--tofqdns-min-ttlmay result in unacceptably slow policy regeneration. See DNS and Long-Lived Connections for details.- The lookups from Cilium follow the configuration of the environment it is in via
/etc/resolv.conf. When running as a kubernetes pod, the contents ofresolv.confare controlled via thednsPolicyfield of a spec. When running directly on a host, it will use the host’s file. Irrespective of how the DNS lookups are configured, TTLs and caches on the resolver will impact the IPs seen by the cilium-agent lookups.
Note
Connections to the DNS resolver must be explicitly whitelisted to allow DNS queries. This is independent of the source of DNS information, whether from polling or the DNS proxy.
Kubernetes¶
This section covers Kubernetes specific network policy aspects.
Namespaces¶
Namespaces are used to create virtual clusters within a Kubernetes cluster. All Kubernetes objects including NetworkPolicy and CiliumNetworkPolicy belong to a particular namespace. Depending on how a policy is being defined and created, Kubernetes namespaces are automatically being taken into account:
- Network policies created and imported as CiliumNetworkPolicy CRD and NetworkPolicy apply within the namespace, i.e. the policy only applies to pods within that namespace. It is however possible to grant access to and from pods in other namespaces as described below.
- Network policies imported directly via the API Reference apply to all namespaces unless a namespace selector is specified as described below.
Note
While specification of the namespace via the label
k8s:io.kubernetes.pod.namespace in the fromEndpoints and
toEndpoints fields is deliberately supported. Specification of the
namespace in the endpointSelector is prohibited as it would
violate the namespace isolation principle of Kubernetes. The
endpointSelector always applies to pods of the namespace which is
associated with the CiliumNetworkPolicy resource itself.
Example: Enforce namespace boundaries¶
This example demonstrates how to enforce Kubernetes namespace-based boundaries
for the namespaces ns1 and ns2 by enabling default-deny on all pods of
either namespace and then allowing communication from all pods within the same
namespace.
Note
The example locks down ingress of the pods in ns1 and ns2.
This means that the pods can still communicate egress to anywhere
unless the destination is in either ns1 or ns2 in which case
both source and destination have to be in the same namespace. In
order to enforce namespace boundaries at egress, the same example can
be used by specifying the rules at egress in addition to ingress.
apiVersion: "cilium.io/v2"
kind: CiliumNetworkPolicy
metadata:
name: "isolate-ns1"
namespace: ns1
spec:
endpointSelector:
matchLabels:
{}
ingress:
- fromEndpoints:
- matchLabels:
{}
---
apiVersion: "cilium.io/v2"
kind: CiliumNetworkPolicy
metadata:
name: "isolate-ns1"
namespace: ns2
spec:
endpointSelector:
matchLabels:
{}
ingress:
- fromEndpoints:
- matchLabels:
{}
[
{
"ingress" : [
{
"fromEndpoints" : [
{
"matchLabels" : {
"k8s:io.kubernetes.pod.namespace" : "ns1"
}
}
]
}
],
"endpointSelector" : {
"matchLabels" : {
"k8s:io.kubernetes.pod.namespace" : "ns1"
}
}
},
{
"endpointSelector" : {
"matchLabels" : {
"k8s:io.kubernetes.pod.namespace" : "ns2"
}
},
"ingress" : [
{
"fromEndpoints" : [
{
"matchLabels" : {
"k8s:io.kubernetes.pod.namespace" : "ns2"
}
}
]
}
]
}
]
Example: Expose pods across namespaces¶
The following example exposes all pods with the label name=leia in the
namespace ns1 to all pods with the label name=luke in the namespace
ns2.
Refer to the example YAML files for a fully functional example including pods deployed to different namespaces.
apiVersion: "cilium.io/v2"
kind: CiliumNetworkPolicy
metadata:
name: "k8s-expose-across-namespace"
namespace: ns1
spec:
endpointSelector:
matchLabels:
name: leia
ingress:
- fromEndpoints:
- matchLabels:
k8s:io.kubernetes.pod.namespace: ns2
name: luke
[{
"labels": [{"key": "name", "value": "k8s-svc-account"}],
"endpointSelector": {
"matchLabels": {"name":"leia", "k8s:io.kubernetes.pod.namespace":"ns1"}
},
"ingress": [{
"fromEndpoints": [{
"matchLabels":{"name": "luke", "k8s:io.kubernetes.pod.namespace":"ns2"}
}]
}]
}]
Example: Allow egress to kube-dns in kube-system namespace¶
The following example allows all pods in the namespace in which the policy is
created to communicate with kube-dns on port 53/UDP in the kube-system
namespace.
apiVersion: "cilium.io/v2"
kind: CiliumNetworkPolicy
metadata:
name: "allow-to-kubedns"
spec:
endpointSelector:
{}
egress:
- toEndpoints:
- matchLabels:
k8s:io.kubernetes.pod.namespace: kube-system
k8s-app: kube-dns
toPorts:
- ports:
- port: '53'
protocol: UDP
[
{
"endpointSelector" : {
"matchLabels" : {}
},
"egress" : [
{
"toEndpoints" : [
{
"matchLabels" : {
"k8s:io.kubernetes.pod.namespace" : "kube-system",
"k8s-app" : "kube-dns"
}
}
],
"toPorts" : [
{
"ports" : [
{
"port" : "53",
"protocol" : "UDP"
}
]
}
]
}
]
}
]
ServiceAccounts¶
Kubernetes Service Accounts are used to associate an identity to a pod or process managed by Kubernetes and grant identities access to Kubernetes resources and secrets. Cilium supports the specification of network security policies based on the service account identity of a pod.
The service account of a pod is either defined via the service account admission controller or can be directly specified in the Pod, Deployment, ReplicationController resource like this:
apiVersion: v1
kind: Pod
metadata:
name: my-pod
spec:
serviceAccountName: leia
...
Example¶
The following example grants any pod running under the service account of
“luke” to issue a HTTP GET /public request on TCP port 80 to all pods
running associated to the service account of “leia”.
Refer to the example YAML files for a fully functional example including deployment and service account resources.
apiVersion: "cilium.io/v2"
kind: CiliumNetworkPolicy
metadata:
name: "k8s-svc-account"
spec:
endpointSelector:
matchLabels:
io.cilium.k8s.policy.serviceaccount: leia
ingress:
- fromEndpoints:
- matchLabels:
io.cilium.k8s.policy.serviceaccount: luke
toPorts:
- ports:
- port: '80'
protocol: TCP
rules:
http:
- method: GET
path: "/public$"
[{
"labels": [{"key": "name", "value": "k8s-svc-account"}],
"endpointSelector": {"matchLabels": {"io.cilium.k8s.policy.serviceaccount":"leia"}},
"ingress": [{
"fromEndpoints": [
{"matchLabels":{"io.cilium.k8s.policy.serviceaccount":"luke"}}
],
"toPorts": [{
"ports": [
{"port": "80", "protocol": "TCP"}
],
"rules": {
"http": [
{
"method": "GET",
"path": "/public$"
}
]
}
}]
}]
}]
Multi-Cluster¶
When operating multiple cluster with cluster mesh, the cluster name is exposed
via the label io.cilium.k8s.policy.cluster and can be used to restrict
policies to a particular cluster.
apiVersion: "cilium.io/v2"
kind: CiliumNetworkPolicy
metadata:
name: "allow-cross-cluster"
description: "Allow x-wing in cluster1 to contact rebel-base in cluster2"
spec:
endpointSelector:
matchLabels:
name: x-wing
io.cilium.k8s.policy.cluster: cluster1
egress:
- toEndpoints:
- matchLabels:
name: rebel-base
io.cilium.k8s.policy.cluster: cluster2
Endpoint Lifecycle¶
This section specifies the lifecycle of Cilium endpoints.
Every endpoint in Cilium is in one of the following states:
restoring: The endpoint was started before Cilium started, and Cilium is restoring its networking configuration.waiting-for-identity: Cilium is allocating a unique identity for the endpoint.waiting-to-regenerate: The endpoint received an identity and is waiting for its networking configuration to be (re)generated.regenerating: The endpoint’s networking configuration is being (re)generated. This includes programming BPF for that endpoint.ready: The endpoint’s networking configuration has been successfully (re)generated.disconnecting: The endpoint is being deleted.disconnected: The endpoint has been deleted.
The state of an endpoint can be queried using the cilium endpoint
list and cilium endpoint get CLI commands.
While an endpoint is running, it transitions between the
waiting-for-identity, waiting-to-regenerate, regenerating,
and ready states. A transition into the waiting-for-identity
state indicates that the endpoint changed its identity. A transition
into the waiting-to-regenerate or regenerating state indicates
that the policy to be enforced on the endpoint has changed because of
a change in identity, policy, or configuration.
An endpoint transitions into the disconnecting state when it is
being deleted, regardless of its current state.
In some environments, notably Docker and Kubernetes, Cilium can’t
determine the labels of an endpoint immediately when the endpoint is
created, and therefore can’t allocate an identity for the endpoint at
that point. Until the endpoint’s labels are known, Cilium temporarily
associates a special single label reserved:init to the endpoint.
When the endpoint’s labels become known, Cilium then replaces that
special label with the endpoint’s labels and allocates a proper
identity to the endpoint.
To allow traffic to/from endpoints while they are initializing, you
can create policy rules that select the reserved:init label,
and/or rules that allow traffic to/from the special init entity.
For instance, writing a rule that allows all initializing endpoints to receive connections from the host and to perform DNS queries may be done as follows:
apiVersion: "cilium.io/v2"
kind: CiliumNetworkPolicy
metadata:
name: init
specs:
- endpointSelector:
matchLabels:
"reserved:init": ""
ingress:
- fromEntities:
- host
egress:
- toEntities:
- all
toPorts:
- ports:
- port: "53"
protocol: UDP
[{
"labels": [{"key": "name", "value": "init"}],
"endpointSelector": {"matchLabels":{"reserved:init":""}},
"ingress": [{
"fromEntities": ["host"]
}],
"egress": [{
"toEntities": ["all"],
"toPorts": [
{"ports":[ {"port": "53", "protocol": "UDP"}]}
]
}]
}]
Likewise, writing a rule that allows an endpoint to receive DNS queries from initializing endpoints may be done as follows:
apiVersion: "cilium.io/v2"
kind: CiliumNetworkPolicy
metadata:
name: "from-init"
spec:
endpointSelector:
matchLabels:
app: myService
ingress:
- fromEntities:
- init
- toPorts:
- ports:
- port: "53"
protocol: UDP
[{
"labels": [{"key": "name", "value": "from-init"}],
"endpointSelector": {"matchLabels":{"app":"myService"}},
"ingress": [{
"fromEntities": ["init"],
"toPorts": [
{"ports":[ {"port": "53", "protocol": "UDP"}]}
]
}]
}]
If any ingress (resp. egress) policy rules selects the
reserved:init label, all ingress (resp. egress) traffic to
(resp. from) initializing endpoints that is not explicitly allowed by
those rules will be dropped. Otherwise, if the policy enforcement
mode is never or default, all ingress (resp. egress) traffic
is allowed to (resp. from) initializing endpoints. Otherwise, all
ingress (resp. egress) traffic is dropped.
Troubleshooting¶
Policy Tracing¶
If Cilium is allowing / denying connections in a way that is not aligned with the
intent of your Cilium Network policy, there is an easy way to
verify if and what policy rules apply between two
endpoints. We can use the cilium policy trace to simulate a policy decision
between the source and destination endpoints.
We will use the example from the Minikube Getting Started Guide to trace the policy. In this example, there is:
deathstarservice identified by labels:org=empire, class=deathstar. The service is backed by two pods.tiefighterspaceship client pod with labels:org=empire, class=tiefighterxwingspaceship client pod with labels:org=alliance, class=xwing
An L3/L4 policy is enforced on the deathstar service to allow access to all spaceships with labels org=empire. With this policy, the tiefighter access is allowed but xwing access will be denied. Let’s use the cilium policy trace to simulate the policy decision. The command provides flexibility to run using pod names, labels or Cilium security identities.
Note
If the --dport option is not specified, then L4 policy will not be
consulted in this policy trace command.
Currently, there is no support for tracing L7 policies via this tool.
# Policy trace using pod name and service labels
$ kubectl exec -ti cilium-88k78 -n kube-system -- cilium policy trace --src-k8s-pod default:xwing -d any:class=deathstar,k8s:org=empire,k8s:io.kubernetes.pod.namespace=default --dport 80
level=info msg="Waiting for k8s api-server to be ready..." subsys=k8s
level=info msg="Connected to k8s api-server" ipAddr="https://10.96.0.1:443" subsys=k8s
----------------------------------------------------------------
Tracing From: [k8s:class=xwing, k8s:io.cilium.k8s.policy.serviceaccount=default, k8s:io.kubernetes.pod.namespace=default, k8s:org=alliance] => To: [any:class=deathstar, k8s:org=empire, k8s:io.kubernetes.pod.namespace=default] Ports: [80/ANY]
* Rule {"matchLabels":{"any:class":"deathstar","any:org":"empire","k8s:io.kubernetes.pod.namespace":"default"}}: selected
Allows from labels {"matchLabels":{"any:org":"empire","k8s:io.kubernetes.pod.namespace":"default"}}
Labels [k8s:class=xwing k8s:io.cilium.k8s.policy.serviceaccount=default k8s:io.kubernetes.pod.namespace=default k8s:org=alliance] not found
1/1 rules selected
Found no allow rule
Label verdict: undecided
Resolving ingress port policy for [any:class=deathstar k8s:org=empire k8s:io.kubernetes.pod.namespace=default]
* Rule {"matchLabels":{"any:class":"deathstar","any:org":"empire","k8s:io.kubernetes.pod.namespace":"default"}}: selected
Labels [k8s:class=xwing k8s:io.cilium.k8s.policy.serviceaccount=default k8s:io.kubernetes.pod.namespace=default k8s:org=alliance] not found
1/1 rules selected
Found no allow rule
L4 ingress verdict: undecided
Final verdict: DENIED
# Get the Cilium security id
$ kubectl exec -ti cilium-88k78 -n kube-system -- cilium endpoint list | egrep 'deathstar|xwing|tiefighter'
ENDPOINT POLICY (ingress) POLICY (egress) IDENTITY LABELS (source:key[=value]) IPv6 IPv4 STATUS
ENFORCEMENT ENFORCEMENT
568 Enabled Disabled 22133 k8s:class=deathstar f00d::a0f:0:0:238 10.15.65.193 ready
900 Enabled Disabled 22133 k8s:class=deathstar f00d::a0f:0:0:384 10.15.114.17 ready
33633 Disabled Disabled 53208 k8s:class=xwing f00d::a0f:0:0:8361 10.15.151.230 ready
38654 Disabled Disabled 22962 k8s:class=tiefighter f00d::a0f:0:0:96fe 10.15.88.156 ready
# Policy trace using Cilium security ids
$ kubectl exec -ti cilium-88k78 -n kube-system -- cilium policy trace --src-identity 53208 --dst-identity 22133 --dport 80
----------------------------------------------------------------
Tracing From: [k8s:class=xwing, k8s:io.cilium.k8s.policy.serviceaccount=default, k8s:io.kubernetes.pod.namespace=default, k8s:org=alliance] => To: [any:class=deathstar, k8s:org=empire, k8s:io.kubernetes.pod.namespace=default] Ports: [80/ANY]
* Rule {"matchLabels":{"any:class":"deathstar","any:org":"empire","k8s:io.kubernetes.pod.namespace":"default"}}: selected
Allows from labels {"matchLabels":{"any:org":"empire","k8s:io.kubernetes.pod.namespace":"default"}}
Labels [k8s:class=xwing k8s:io.cilium.k8s.policy.serviceaccount=default k8s:io.kubernetes.pod.namespace=default k8s:org=alliance] not found
1/1 rules selected
Found no allow rule
Label verdict: undecided
Resolving ingress port policy for [any:class=deathstar k8s:org=empire k8s:io.kubernetes.pod.namespace=default]
* Rule {"matchLabels":{"any:class":"deathstar","any:org":"empire","k8s:io.kubernetes.pod.namespace":"default"}}: selected
Labels [k8s:class=xwing k8s:io.cilium.k8s.policy.serviceaccount=default k8s:io.kubernetes.pod.namespace=default k8s:org=alliance] not found
1/1 rules selected
Found no allow rule
L4 ingress verdict: undecided
Final verdict: DENIED
Policy Rule to Endpoint Mapping¶
To determine which policy rules are currently in effect for an endpoint the
data from cilium endpoint list and cilium endpoint get can be paired
with the data from cilium policy get. cilium endpoint get will list the
labels of each rule that applies to an endpoint. The list of labels can be
passed to cilium policy get to show that exact source policy. Note that
rules that have no labels cannot be fetched alone (a no label cililum policy
get returns the complete policy on the node). Rules with the same labels will
be returned together.
In the above example, for one of the deathstar pods the endpoint id is 568. We can print all policies applied to it with:
# Get a shell on the Cilium pod
$ kubectl exec -ti cilium-88k78 -n kube-system /bin/bash
# print out the Layer 4 ingress labels
# clean up the data
# fetch each policy via each set of labels
$ cilium endpoint get 568 -o jsonpath='{range ..status.policy.realized.l4.ingress[*].derived-from-rules}{@}{"\n"}{end}'|tr -d '][' | xargs -I{} bash -c 'echo "Labels: {}"; cilium policy get {}'
Labels: k8s:io.cilium.k8s.policy.name=rule1 k8s:io.cilium.k8s.policy.namespace=default
[
{
"endpointSelector": {
"matchLabels": {
"any:class": "deathstar",
"any:org": "empire",
"k8s:io.kubernetes.pod.namespace": "default"
}
},
"ingress": [
{
"fromEndpoints": [
{
"matchLabels": {
"any:org": "empire",
"k8s:io.kubernetes.pod.namespace": "default"
}
}
],
"toPorts": [
{
"ports": [
{
"port": "80",
"protocol": "TCP"
}
],
"rules": {
"http": [
{
"path": "/v1/request-landing",
"method": "POST"
}
]
}
}
]
}
],
"labels": [
{
"key": "io.cilium.k8s.policy.name",
"value": "rule1",
"source": "k8s"
},
{
"key": "io.cilium.k8s.policy.namespace",
"value": "default",
"source": "k8s"
}
]
}
]
Revision: 217
# repeat for L4 egress and L3
$ cilium endpoint get 568 -o jsonpath='{range ..status.policy.realized.l4.egress[*].derived-from-rules}{@}{"\n"}{end}' | tr -d '][' | xargs -I{} bash -c 'echo "Labels: {}"; cilium policy get {}'
$ cilium endpoint get 568 -o jsonpath='{range ..status.policy.realized.cidr-policy.ingress[*].derived-from-rules}{@}{"\n"}{end}' | tr -d '][' | xargs -I{} bash -c 'echo "Labels: {}"; cilium policy get {}'
$ cilium endpoint get 568 -o jsonpath='{range ..status.policy.realized.cidr-policy.egress[*].derived-from-rules}{@}{"\n"}{end}' | tr -d '][' | xargs -I{} bash -c 'echo "Labels: {}"; cilium policy get {}'
Troubleshooting toFQDNs rules¶
The effect of toFQDNs may change long after a policy is applied, as DNS
data changes. This can make it difficult to debug unexpectedly blocked
connections, or transient failures. Cilium amends the internal policy as it
sees DNS IP information and this can be obtained with via cilium policy
get. In every rule with a toFQDNs a corresponding toCIDRSet rule is
present with the derived IPs that Cilium will allow.
{
"toCIDRSet": [
{
"cidr": "104.198.14.52/32"
}
],
"toFQDNs": [
{
"matchPattern": "cilium.io"
}
]
}
The per-Endpoint status from cilium includes the labels of the
original rules that caused the toCIDRSet to be generated. This can be
obtained with cilium endpoint get <endpoint ID>, or kubectl get cep
podname when running in kubernetes.
cidr-policy:
egress:
- derived-from-rules:
- - k8s:io.cilium.k8s.policy.name=rebel-escape
- k8s:io.cilium.k8s.policy.uid=c96f66a8-135e-11e9-babd-080027d2d952
- k8s:io.cilium.k8s.policy.namespace=default
- k8s:io.cilium.k8s.policy.derived-from=CiliumNetworkPolicy
- cilium-generated:ToFQDN-UUID=4cee1da1-1361-11e9-a6d4-080027d2d952
rule: 104.198.14.52/32
ingress: []
{
"cidr-policy": {
"egress": [
{
"derived-from-rules": [
[
"k8s:io.cilium.k8s.policy.name=rebel-escape",
"k8s:io.cilium.k8s.policy.uid=c96f66a8-135e-11e9-babd-080027d2d952",
"k8s:io.cilium.k8s.policy.namespace=default",
"k8s:io.cilium.k8s.policy.derived-from=CiliumNetworkPolicy",
"cilium-generated:ToFQDN-UUID=9a1d4006-1360-11e9-a6d4-080027d2d952"
]
],
"rule": "104.198.14.52/32"
}
],
"ingress": []
}
}
Monitoring & Metrics¶
cilium-agent can be configured to serve Prometheus
metrics. Prometheus is a pluggable metrics collection and storage system and
can act as a data source for Grafana, a metrics
visualization frontend. Unlike some metrics collectors like statsd, Prometheus requires the
collectors to pull metrics from each source.
To expose any metrics, invoke cilium-agent with the
--prometheus-serve-addr option. This option takes a IP:Port pair but
passing an empty IP (e.g. :9090) will bind the server to all available
interfaces (there is usually only one in a container).
Exported Metrics¶
All metrics are exported under the cilium Prometheus namespace. When
running and collecting in Kubernetes they will be tagged with a pod name and
namespace.
Endpoint¶
endpoint_count: Number of endpoints managed by this agentendpoint_regenerating: Number of endpoints currently regenerating. Deprecated. Use endpoint_state with proper labels insteadendpoint_regenerations: Count of all endpoint regenerations that have completed, tagged by outcomeendpoint_regeneration_time_stats_seconds: Endpoint regeneration time stats labeled by scope.endpoint_state: Count of all endpoints, tagged by different endpoint states
Build Queue¶
buildqueue_entries: Number of queued, waiting, and running builds.state=running: Number of builds currently in progressstate=blocked: Number of builds selected for building, waiting for build conditions to be met.state=waiting: Number of builds in the queue, waiting to be selected.
Services¶
services_events_total: Number of services events labeled by action type
Datapath¶
datapath_errors_total: Total number of errors occurred in datapath management, labeled by area, name and address family.datapath_conntrack_gc_runs_total: Number of times that the conntrack garbage collector process was run. It contains a label status that describes if it was successful or not.datapath_conntrack_gc_key_fallbacks_total: Number of times that the Key fallback was invalid.datapath_conntrack_gc_entries: The number of alive and deleted conntrack entries at the end of a garbage collector run labeled by datapath family.datapath_conntrack_gc_duration_seconds: Duration in seconds of the garbage collector process labeled by datapath and completion status.
BPF¶
bpf_syscall_duration_seconds: Duration of BPF system call performed * Labels:operation={lookup, delete, update, objPin, getNextKey, ...},outcome={success|failure}bpf_map_ops_total: Number of BPF map operations performed * Labels:mapName=<string>,operation={delete|update},outcome={success|failure}
Drops/Forwards (L3/L4)¶
drop_count_total: Total dropped packets, tagged by drop reason and ingress/egress directiondrop_bytes_total: Total dropped bytes, tagged by drop reason and ingress/egress directionforward_count_total: Total forwarded packets, tagged by ingress/egress directionforward_bytes_total: Total forwarded bytes, tagged by ingress/egress direction
Policy¶
policy_count: Number of policies currently loadedpolicy_regeneration_total: Total number of policies regenerated successfullypolicy_regeneration_time_stats_seconds: Policy regeneration time stats labeled by the scope.policy_max_revision: Highest policy revision number in the agentpolicy_import_errors: Number of times a policy import has failedpolicy_endpoint_enforcement_status: Number of endpoints labeled by policy enforcement status.
Policy L7 (HTTP/Kafka)¶
proxy_redirects: Number of redirects installed for endpoints, labeled by protocolproxy_upstream_reply_seconds: Seconds waited for upstream server to reply to a requestpolicy_l7_parse_errors_total: Number of total L7 parse errorspolicy_l7_forwarded_total: Number of total L7 forwarded requests/responsespolicy_l7_denied_total: Number of total L7 denied requests/responses due to policypolicy_l7_received_total: Number of total L7 received requests/responses
Events external to Cilium¶
event_ts: Last timestamp when we received an event. Further labeled by source:api,containerd,k8s.
Controllers¶
controllers_runs_total: Number of times that a controller process was run labeled by completion statuscontrollers_runs_duration_seconds: Duration in seconds of the controller process labeled by completion status
SubProcess¶
subprocess_start_total: Number of times that Cilium has started a subprocess, labeled by subsystem
Kubernetes¶
kubernetes_events_received_total: Number of Kubernetes events received labeled by scope, action, validity and equalitykubernetes_events_total: Number of Kubernetes events processed labeled by scope, action and the execution resultk8s_cnp_status_completion_seconds: Duration in seconds in how long it took to complete a CNP status update labeled by number of attempts and outcome.
IPAM¶
ipam_events_total: Number of IPAM events received labeled by action and datapath family type
KVstore¶
kvstore_operations_duration_seconds: Duration of kvstore operation- Labels:
action,kind,outcome,scope
- Labels:
kvstore_events_queue_seconds: Duration of seconds of time received event was blocked before it could be queued- Labels:
action,scope
- Labels:
Agent¶
agent_bootstrap_seconds: Duration of various bootstrap phases * Labels:scope,outcomeapi_process_time_seconds: Processing time of all the API calls made to the cilium-agent, labeled by API method, API path and returned HTTP code.
FQDN¶
fqdn_gc_deletions_total: Number of FQDNs that have been cleaned on FQDN Garbage collector job
Cilium as a Kubernetes pod¶
The Cilium Prometheus reference configuration configures jobs that automatically collect pod metrics marked with the appropriate two labels can be found in examples/kubernetes/addons/prometheus/templates/04-prometheus.yaml
Your Cilium spec will need these annotations:
prometheus.io/scrape: "true"
prometheus.io/port: "9090"
The reference Cilium Kubernetes DaemonSet Kubernetes descriptor examples/kubernetes/1.13/cilium.yaml
is an example of how to configure cilium-agent and set the appropriate labels.
Note: the port can be configured per-pod to any value and the label set accordingly. Prometheus uses this label to discover the port.
To configure automatic metric discovery and collection, Prometheus itself requires a kubernetes_sd_config configuration. The configured rules are used to filter pods and nodes by label and annotation, and tag the resulting metrics series. In the Kubernetes case Prometheus will contact the Kubernetes API server for these lists and must have permissions to do so.
An example of a Prometheus configuration can be found alongside the reference Cilium Kubernetes DaemonSet spec in examples/kubernetes/addons/prometheus/templates/04-prometheus.yaml
The critical discovery section is:
- job_name: 'kubernetes-pods'
kubernetes_sd_configs:
- role: pod
relabel_configs:
- source_labels: [__meta_kubernetes_pod_label_k8s_app]
action: keep
regex: cilium
- source_labels: [__meta_kubernetes_pod_annotation_prometheus_io_scrape]
action: keep
regex: true
- source_labels: [__address__, __meta_kubernetes_pod_annotation_prometheus_io_port]
action: replace
regex: (.+):(?:\d+);(\d+)
replacement: ${1}:${2}
target_label: __address__
- source_labels: [__meta_kubernetes_pod_annotation_prometheus_io_path]
action: replace
target_label: __metrics_path__
regex: (.+)
- action: labelmap
regex: __meta_kubernetes_pod_label_(.+)
- source_labels: [__meta_kubernetes_namespace]
action: replace
target_label: kubernetes_namespace
- source_labels: [__meta_kubernetes_pod_name]
action: replace
target_label: kubernetes_pod_name
This job configures prometheus to do a number of things for all pods returned by the Kubernetes API server:
- find and keep all pods that have labels
k8s-app=ciliumandprometheus.io/scrape=true - extract the IP and port of the pod from
addressandprometheus.io/port - discover the metrics URL path from the label
prometheus.io/pathor use the default of/metricswhen it isn’t present - populate metrics tags for the Kubernetes namespace and pod name derived from the pod labels
Cilium as a host-agent on a node¶
Prometheus can use a number of more common service discovery schemes, such as consul and DNS, or a cloud provider API, such as AWS, GCE or Azure. Prometheus documentation contains more information.
It is also possible to hard-code static-config sections that simply contain
a hardcoded IP address and port:
- job_name: 'cilium-agent-nodes'
metrics_path: /metrics
static_configs:
- targets: ['192.168.33.11:9090']
labels:
node-id: i-0598c7d7d356eba47
node-az: a
Troubleshooting¶
This document describes how to troubleshoot Cilium in different deployment modes. It focuses on a full deployment of Cilium within a datacenter or public cloud. If you are just looking for a simple way to experiment, we highly recommend trying out the Getting Started Guides instead.
This guide assumes that you have read the Concepts which explains all the components and concepts.
We use GitHub issues to maintain a list of Cilium Frequently Asked Questions (FAQ). You can also check there to see if your question(s) is already addressed.
Component & Cluster Health¶
Kubernetes¶
An initial overview of Cilium can be retrieved by listing all pods to verify
whether all pods have the status Running:
$ kubectl -n kube-system get pods -l k8s-app=cilium
NAME READY STATUS RESTARTS AGE
cilium-2hq5z 1/1 Running 0 4d
cilium-6kbtz 1/1 Running 0 4d
cilium-klj4b 1/1 Running 0 4d
cilium-zmjj9 1/1 Running 0 4d
If Cilium encounters a problem that it cannot recover from, it will
automatically report the failure state via cilium status which is regularly
queried by the Kubernetes liveness probe to automatically restart Cilium pods.
If a Cilium pod is in state CrashLoopBackoff then this indicates a
permanent failure scenario.
Detailed Status¶
If a particular Cilium pod is not in running state, the status and health of
the agent on that node can be retrieved by running cilium status in the
context of that pod:
$ kubectl -n kube-system exec -ti cilium-2hq5z -- cilium status
KVStore: Ok etcd: 1/1 connected: http://demo-etcd-lab--a.etcd.tgraf.test1.lab.corp.covalent.link:2379 - 3.2.5 (Leader)
ContainerRuntime: Ok docker daemon: OK
Kubernetes: Ok OK
Kubernetes APIs: ["cilium/v2::CiliumNetworkPolicy", "networking.k8s.io/v1::NetworkPolicy", "core/v1::Service", "core/v1::Endpoint", "core/v1::Node", "CustomResourceDefinition"]
Cilium: Ok OK
NodeMonitor: Disabled
Cilium health daemon: Ok
Controller Status: 14/14 healthy
Proxy Status: OK, ip 10.2.0.172, port-range 10000-20000
Cluster health: 4/4 reachable (2018-06-16T09:49:58Z)
Alternatively, the k8s-cilium-exec.sh script can be used to run cilium
status on all nodes. This will provide detailed status and health information
of all nodes in the cluster:
$ curl -sLO releases.cilium.io/v1.1.0/tools/k8s-cilium-exec.sh
$ chmod +x ./k8s-cilium-exec.sh
… and run cilium status on all nodes:
$ ./k8s-cilium-exec.sh cilium status
KVStore: Ok Etcd: http://127.0.0.1:2379 - (Leader) 3.1.10
ContainerRuntime: Ok
Kubernetes: Ok OK
Kubernetes APIs: ["extensions/v1beta1::Ingress", "core/v1::Node", "CustomResourceDefinition", "cilium/v2::CiliumNetworkPolicy", "networking.k8s.io/v1::NetworkPolicy", "core/v1::Service", "core/v1::Endpoint"]
Cilium: Ok OK
NodeMonitor: Listening for events on 2 CPUs with 64x4096 of shared memory
Cilium health daemon: Ok
Controller Status: 7/7 healthy
Proxy Status: OK, ip 10.15.28.238, 0 redirects, port-range 10000-20000
Cluster health: 1/1 reachable (2018-02-27T00:24:34Z)
Logs¶
To retrieve log files of a cilium pod, run (replace cilium-1234 with a pod
name returned by kubectl -n kube-system get pods -l k8s-app=cilium)
$ kubectl -n kube-system logs --timestamps cilium-1234
If the cilium pod was already restarted due to the liveness problem after encountering an issue, it can be useful to retrieve the logs of the pod before the last restart:
$ kubectl -n kube-system logs --timestamps -p cilium-1234
Generic¶
When logged in a host running Cilium, the cilium CLI can be invoked directly, e.g.:
$ cilium status
KVStore: Ok etcd: 1/1 connected: https://192.168.33.11:2379 - 3.2.7 (Leader)
ContainerRuntime: Ok
Kubernetes: Ok OK
Kubernetes APIs: ["core/v1::Endpoint", "extensions/v1beta1::Ingress", "core/v1::Node", "CustomResourceDefinition", "cilium/v2::CiliumNetworkPolicy", "networking.k8s.io/v1::NetworkPolicy", "core/v1::Service"]
Cilium: Ok OK
NodeMonitor: Listening for events on 2 CPUs with 64x4096 of shared memory
Cilium health daemon: Ok
IPv4 address pool: 261/65535 allocated
IPv6 address pool: 4/4294967295 allocated
Controller Status: 20/20 healthy
Proxy Status: OK, ip 10.0.28.238, port-range 10000-20000
Cluster health: 2/2 reachable (2018-04-11T15:41:01Z)
Connectivity Problems¶
Checking cluster connectivity health¶
Cilium allows to rule out network fabric related issues when troubleshooting connectivity issues by providing reliable health and latency probes between all cluster nodes and between a simulated workload running on each node.
By default when Cilium is run, it launches instances of cilium-health in
the background to determine overall connectivity status of the cluster. This
tool periodically runs bidirectional traffic across multiple paths through the
cluster and through each node using different protocols to determine the health
status of each path and protocol. At any point in time, cilium-health may be
queried for the connectivity status of the last probe.
$ kubectl -n kube-system exec -ti cilium-2hq5z -- cilium-health status
Probe time: 2018-06-16T09:51:58Z
Nodes:
ip-172-0-52-116.us-west-2.compute.internal (localhost):
Host connectivity to 172.0.52.116:
ICMP to stack: OK, RTT=315.254µs
HTTP to agent: OK, RTT=368.579µs
Endpoint connectivity to 10.2.0.183:
ICMP to stack: OK, RTT=190.658µs
HTTP to agent: OK, RTT=536.665µs
ip-172-0-117-198.us-west-2.compute.internal:
Host connectivity to 172.0.117.198:
ICMP to stack: OK, RTT=1.009679ms
HTTP to agent: OK, RTT=1.808628ms
Endpoint connectivity to 10.2.1.234:
ICMP to stack: OK, RTT=1.016365ms
HTTP to agent: OK, RTT=2.29877ms
For each node, the connectivity will be displayed for each protocol and path,
both to the node itself and to an endpoint on that node. The latency specified
is a snapshot at the last time a probe was run, which is typically once per
minute. The ICMP connectivity row represents Layer 3 connectivity to the
networking stack, while the HTTP connectivity row represents connection to an
instance of the cilium-health agent running on the host or as an endpoint.
Monitoring Packet Drops¶
Sometimes you may experience broken connectivity, which may be due to a
number of different causes. A main cause can be unwanted packet drops on
the networking level. The tool
cilium monitor allows you to quickly inspect and see if and where packet
drops happen. Following is an example output (use kubectl exec as in previous
examples if running with Kubernetes):
$ kubectl -n kube-system exec -ti cilium-2hq5z -- cilium monitor --type drop
Listening for events on 2 CPUs with 64x4096 of shared memory
Press Ctrl-C to quit
xx drop (Policy denied (L3)) to endpoint 25729, identity 261->264: fd02::c0a8:210b:0:bf00 -> fd02::c0a8:210b:0:6481 EchoRequest
xx drop (Policy denied (L3)) to endpoint 25729, identity 261->264: fd02::c0a8:210b:0:bf00 -> fd02::c0a8:210b:0:6481 EchoRequest
xx drop (Policy denied (L3)) to endpoint 25729, identity 261->264: 10.11.13.37 -> 10.11.101.61 EchoRequest
xx drop (Policy denied (L3)) to endpoint 25729, identity 261->264: 10.11.13.37 -> 10.11.101.61 EchoRequest
xx drop (Invalid destination mac) to endpoint 0, identity 0->0: fe80::5c25:ddff:fe8e:78d8 -> ff02::2 RouterSolicitation
The above indicates that a packet to endpoint ID 25729 has been dropped due
to violation of the Layer 3 policy.
Handling drop (CT: Map insertion failed)¶
If connectivity fails and cilium monitor --type drop shows xx drop (CT:
Map insertion failed), then it is likely that the connection tracking table
is filling up and the automatic adjustment of the garbage collector interval is
insufficient. Set --conntrack-gc-interval to an interval lower than the
default. Alternatively, the value for bpf-ct-global-any-max and
bpf-ct-global-tcp-max can be increased. Setting both of these options will
be a trade-off of CPU for conntrack-gc-interval, and for
bpf-ct-global-any-max and bpf-ct-global-tcp-max the amount of memory
consumed.
Policy Troubleshooting¶
Ensure pod is managed by Cilium¶
A potential cause for policy enforcement not functioning as expected is that the networking of the pod selected by the policy is not being managed by Cilium. The following situations result in unmanaged pods:
- The pod is running in host networking and will use the host’s IP address directly. Such pods have full network connectivity but Cilium will not provide security policy enforcement for such pods.
- The pod was started before Cilium was deployed. Cilium only manages pods that have been deployed after Cilium itself was started. Cilium will not provide security policy enforcement for such pods.
If pod networking is not managed by Cilium. Ingress and egress policy rules selecting the respective pods will not be applied. See the section Network Policy for more details.
You can run the following script to list the pods which are not managed by Cilium:
$ ./contrib/k8s/k8s-unmanaged.sh
kube-system/cilium-hqpk7
kube-system/kube-addon-manager-minikube
kube-system/kube-dns-54cccfbdf8-zmv2c
kube-system/kubernetes-dashboard-77d8b98585-g52k5
kube-system/storage-provisioner
See section Troubleshooting for details and examples on how to use the policy tracing feature.
Understand the rendering of your policy¶
There are always multiple ways to approach a problem. Cilium can provide the rendering of the aggregate policy provided to it, leaving you to simply compare with what you expect the policy to actually be rather than search (and potentially overlook) every policy. At the expense of reading a very large dump of an endpoint, this is often a faster path to discovering errant policy requests in the Kubernetes API.
Start by finding the endpoint you are debugging from the following list. There are several cross references for you to use in this list, including the IP address and pod labels:
kubectl -n kube-system exec -ti cilium-q8wvt -- cilium endpoint list
When you find the correct endpoint, the first column of every row is the endpoint ID. Use that to dump the full endpoint information:
kubectl -n kube-system exec -ti cilium-q8wvt -- cilium endpoint get 59084
Importing this dump into a JSON-friendly editor can help browse and navigate the information here. At the top level of the dump, there are two nodes of note:
spec: The desired state of the endpointstatus: The current state of the endpoint
This is the standard Kubernetes control loop pattern. Cilium is the controller here,
and it is iteratively working to bring the status in line with the spec.
Opening the status, we can drill down through policy.realized.l4. Do your
ingress and egress rules match what you expect? If not, the reference to the errant
rules can be found in the derived-from-rules node.
Automatic Diagnosis¶
The cluster-diagnosis tool can help identify the most commonly encountered
issues in Cilium deployments. The tool currently supports Kubernetes
and Minikube clusters only.
The tool performs various checks and provides hints to fix specific issues that it has identified.
The following is a list of prerequisites:
- Requires Python >= 2.7.*
- Requires
kubectl. kubectlshould be pointing to your cluster before running the tool.
You can download the latest version of the cluster-diagnosis.zip file using the following command:
curl -sLO releases.cilium.io/tools/cluster-diagnosis.zip
Command to run the cluster-diagnosis tool:
python cluster-diagnosis.zip
Command to collect the system dump using the cluster-diagnosis tool:
python cluster-diagnosis.zip sysdump
Symptom Library¶
Node to node traffic is being dropped¶
Symptom¶
Endpoint to endpoint communication on a single node succeeds but communication fails between endpoints across multiple nodes.
Troubleshooting steps:¶
- Run
cilium-health statuson the node of the source and destination endpoint. It should describe the connectivity from that node to other nodes in the cluster, and to a simulated endpoint on each other node. Identify points in the cluster that cannot talk to each other. If the command does not describe the status of the other node, there may be an issue with the KV-Store. - Run
cilium monitoron the node of the source and destination endpoint. Look for packet drops.
When running in Overlay Network Mode mode:
Run
cilium bpf tunnel listand verify that each Cilium node is aware of the other nodes in the cluster. If not, check the logfile for errors.If nodes are being populated correctly, run
tcpdump -n -i cilium_vxlanon each node to verify whether cross node traffic is being forwarded correctly between nodes.If packets are being dropped,
- verify that the node IP listed in
cilium bpf tunnel listcan reach each other. - verify that the firewall on each node allows UDP port 8472.
- verify that the node IP listed in
When running in Direct / Native Routing Mode mode:
- Run
ip routeor check your cloud provider router and verify that you have routes installed to route the endpoint prefix between all nodes. - Verify that the firewall on each node permits to route the endpoint IPs.
Useful Scripts¶
Retrieve Cilium pod managing a particular pod¶
Identifies the Cilium pod that is managing a particular pod in a namespace:
k8s-get-cilium-pod.sh <pod> <namespace>
Example:
$ curl -sLO releases.cilium.io/v1.1.0/tools/k8s-get-cilium-pod.sh
$ ./k8s-get-cilium-pod.sh luke-pod default
cilium-zmjj9
Execute a command in all Kubernetes Cilium pods¶
Run a command within all Cilium pods of a cluster
k8s-cilium-exec.sh <command>
Example:
$ curl -sLO releases.cilium.io/v1.1.0/tools/k8s-cilium-exec.sh
$ ./k8s-cilium-exec.sh uptime
10:15:16 up 6 days, 7:37, 0 users, load average: 0.00, 0.02, 0.00
10:15:16 up 6 days, 7:32, 0 users, load average: 0.00, 0.03, 0.04
10:15:16 up 6 days, 7:30, 0 users, load average: 0.75, 0.27, 0.15
10:15:16 up 6 days, 7:28, 0 users, load average: 0.14, 0.04, 0.01
List unmanaged Kubernetes pods¶
Lists all Kubernetes pods in the cluster for which Cilium does not provide networking. This includes pods running in host-networking mode and pods that were started before Cilium was deployed.
k8s-unmanaged.sh
Example:
$ curl -sLO releases.cilium.io/v1.1.0/tools/k8s-unmanaged.sh
$ ./k8s-unmanaged.sh
kube-system/cilium-hqpk7
kube-system/kube-addon-manager-minikube
kube-system/kube-dns-54cccfbdf8-zmv2c
kube-system/kubernetes-dashboard-77d8b98585-g52k5
kube-system/storage-provisioner
Reporting a problem¶
Automatic log & state collection¶
Before you report a problem, make sure to retrieve the necessary information from your cluster before the failure state is lost. Cilium provides a script to automatically grab logs and retrieve debug information from all Cilium pods in the cluster.
The script has the following list of prerequisites:
- Requires Python >= 2.7.*
- Requires
kubectl. kubectlshould be pointing to your cluster before running the tool.
You can download the latest version of the cluster-diagnosis.zip file using the following command:
$ curl -sLO releases.cilium.io/tools/cluster-diagnosis.zip
$ python cluster-diagnosis.zip sysdump
Single Node Bugtool¶
If you are not running Kubernetes, it is also possible to run the bug collection tool manually with the scope of a single node:
The cilium-bugtool captures potentially useful information about your
environment for debugging. The tool is meant to be used for debugging a single
Cilium agent node. In the Kubernetes case, if you have multiple Cilium pods,
the tool can retrieve debugging information from all of them. The tool works by
archiving a collection of command output and files from several places. By
default, it writes to the tmp directory.
Note that the command needs to be run from inside the Cilium pod/container.
$ cilium-bugtool
When running it with no option as shown above, it will try to copy various
files and execute some commands. If kubectl is detected, it will search for
Cilium pods. The default label being k8s-app=cilium, but this and the
namespace can be changed via k8s-namespace and k8s-label respectively.
If you’d prefer to browse the dump, there is a HTTP flag.
$ cilium-bugtool --serve
If you want to capture the archive from a Kubernetes pod, then the process is a bit different
# First we need to get the Cilium pod
$ kubectl get pods --namespace kube-system
NAME READY STATUS RESTARTS AGE
cilium-kg8lv 1/1 Running 0 13m
kube-addon-manager-minikube 1/1 Running 0 1h
kube-dns-6fc954457d-sf2nk 3/3 Running 0 1h
kubernetes-dashboard-6xvc7 1/1 Running 0 1h
# Run the bugtool from this pod
$ kubectl -n kube-system exec cilium-kg8lv cilium-bugtool
[...]
# Copy the archive from the pod
$ kubectl cp kube-system/cilium-kg8lv:/tmp/cilium-bugtool-20180411-155146.166+0000-UTC-266836983.tar /tmp/cilium-bugtool-20180411-155146.166+0000-UTC-266836983.tar
[...]
Note
Please check the archive for sensitive information and strip it away before sharing it with us.
Below is an approximate list of the kind of information in the archive.
- Cilium status
- Cilium version
- Kernel configuration
- Resolve configuration
- Cilium endpoint state
- Cilium logs
- Docker logs
dmesgethtoolip aip linkip riptables-savekubectl -n kube-system get podskubectl get pods,svc for all namespacesunameuptimecilium bpf * listcilium endpoint get for each endpointcilium endpoint listhostnamecilium policy getcilium service list- …
Debugging information¶
If you are not running Kubernetes, you can use the cilium debuginfo command
to retrieve useful debugging information. If you are running Kubernetes, this
command is automatically run as part of the system dump.
cilium debuginfo can print useful output from the Cilium API. The output
format is in Markdown format so this can be used when reporting a bug on the
issue tracker. Running without arguments will print to standard output, but
you can also redirect to a file like
$ cilium debuginfo -f debuginfo.md
Note
Please check the debuginfo file for sensitive information and strip it away before sharing it with us.
Slack Assistance¶
The Cilium slack community is helpful first point of assistance to get help troubleshooting a problem or to discuss options on how to address a problem.
The slack community is open to everyone. You can request an invite email by visiting Slack.
Report an issue via GitHub¶
If you believe to have found an issue in Cilium, please report a GitHub issue and make sure to attach a system dump as described above to ensure that developers have the best chance to reproduce the issue.
Special Interest Groups¶
All SIGs¶
The following is a list of special interest groups (SIG) that are meeting on a regular interval. See the respective slack channel for exact meeting cadence and meeting links.
| SIG | Meeting | Slack | Description |
|---|---|---|---|
| Datapath | Every 2 weeks | #sig-datapath | Owner of all BPF and Linux kernel related datapath code. |
| Documentation | None | #sig-docs | All documentation related discussions |
| Envoy | Every 2 weeks | #sig-envoy | Envoy, Istio and maintenance of all L7 protocol parsers. |
| Policy | Every Wed, 9:30 PT (Policy-Zoom) | #sig-policy | All topics related to policy. The SIG is responsible for all security relevant APIs and the enforcement logic. |
| Release Management | None | #launchpad | Responsible for the release management and backport process. |
How to create a SIG¶
- Open a new GitHub issue
- Specify the title “SIG-Request: <Name>”
- Provide a description
- Find two Cilium committers to support the SIG.
- Ask on #development to get the Slack channel and Zoom meeting created
- Submit a PR to update the documentation to get your new SIG listed
Slack¶
The Cilium community is maintaining an active Slack channel. Click here to request an invite.
Slack channels¶
| Name | Purpose |
|---|---|
| #bpf | BPF specific questions |
| #development | Development discussions |
| #general | General user discussions & questions |
| #git | GitHub notifications |
| #kubernetes | Kubernetes specific questions |
| #sig-* | SIG specific discussions |
| #testing | CI and testing related discussions |
Developer / Contributor Guide¶
We’re happy you’re interested in contributing to the Cilium project.
This guide will help you make sure you have an environment capable of testing changes to the Cilium source code, and that you understand the workflow of getting these changes reviewed and merged upstream.
Setting up the development environment¶
Requirements¶
You need to have the following tools available in order to effectively contribute to Cilium:
| Dependency | Version / Commit ID | Download Command |
|---|---|---|
| git | latest | N/A (OS-specific) |
| glibc-devel (32-bit) | latest | N/A (OS-specific) |
| go | 1.12.17 | N/A (OS-specific) |
| dep | >= v0.4.1 | curl https://raw.githubusercontent.com/golang/dep/master/install.sh | sh |
| go-bindata | a0ff2567cfb |
go get -u github.com/cilium/go-bindata/... |
| ginkgo | >= 1.4.0 | go get -u github.com/onsi/ginkgo/ginkgo |
| gomega | >= 1.2.0 | go get -u github.com/onsi/gomega |
| ineffassign | >= 1003c8b |
go get -u github.com/gordonklaus/ineffassign |
| Docker | OS-Dependent | N/A (OS-specific) |
| Docker-Compose | OS-Dependent | N/A (OS-specific) |
To run Cilium locally on VMs, you need:
| Dependency | Version / Commit ID | Download Command |
|---|---|---|
| Vagrant | >= 2.0 | Vagrant Install Instructions |
| VirtualBox (if not using libvirt) | >= 5.2 | N/A (OS-specific) |
Finally, in order to build the documentation, you should have Sphinx installed:
$ sudo pip install sphinx
You should start with the Getting Started Guides, which walks you through the set-up, such as installing Vagrant, getting the Cilium sources, and going through some Cilium basics.
Vagrant Setup¶
While the Getting Started Guides uses a Vagrantfile tuned for the basic walk through, the
setup for the Vagrantfile in the root of the Cilium tree depends on a number of
environment variables and network setup that are managed via
contrib/vagrant/start.sh.
Using the provided Vagrantfile¶
To bring up a Vagrant VM with Cilium plus dependencies installed, run:
$ contrib/vagrant/start.sh
This will create and run a vagrant VM based on the base box
cilium/ubuntu. The box is currently available for the
following providers:
- virtualbox
Options¶
The following environment variables can be set to customize the VMs brought up by vagrant:
NWORKERS=n: Number of child nodes you want to start with the master, default 0.RELOAD=1: Issue avagrant reloadinstead ofvagrant up, useful to resume halted VMs.NFS=1: Use NFS for vagrant shared directories instead of rsync.K8S=1: Build & install kubernetes on the nodes.k8s1is the master node, which contains both master components: etcd, kube-controller-manager, kube-scheduler, kube-apiserver, and node components: kubelet, kube-proxy, kubectl and Cilium. When used in combination withNWORKERS=1a second node is created, wherek8s2will be a kubernetes node, which contains: kubelet, kube-proxy, kubectl and cilium.IPV4=1: Run Cilium with IPv4 enabled.RUNTIME=x: Sets up the container runtime to be used inside a kubernetes cluster. Valid options are:docker,containerdandcrio. If not set, it defaults todocker.VAGRANT_DEFAULT_PROVIDER={virtualbox \| libvirt \| ...}VM_SET_PROXY=https://127.0.0.1:80/Sets up VM’shttps_proxy.
If you want to start the VM with cilium enabled with containerd, with
kubernetes installed and plus a worker, run:
$ RUNTIME=containerd K8S=1 NWORKERS=1 contrib/vagrant/start.sh
If you want to get VM status, run:
$ RUNTIME=containerd K8S=1 NWORKERS=1 vagrant status
If you want to connect to the Kubernetes cluster running inside the developer VM via kubectl from your host machine, set KUBECONFIG environment variable to include new kubeconfig file:
$ export KUBECONFIG=$KUBECONFIG:$GOPATH/src/github.com/cilium/cilium/vagrant.kubeconfig
and add 127.0.0.1 k8s1 to your hosts file.
If you have any issue with the provided vagrant box
cilium/ubuntu or need a different box format, you may
build the box yourself using the packer scripts
Manual Installation¶
Alternatively you can import the vagrant box cilium/ubuntu
directly and manually install Cilium:
$ vagrant init cilium/ubuntu
$ vagrant up
$ vagrant ssh [...]
$ cd go/src/github.com/cilium/cilium/
$ make
$ sudo make install
$ sudo mkdir -p /etc/sysconfig/
$ sudo cp contrib/systemd/cilium.service /etc/systemd/system/
$ sudo cp contrib/systemd/cilium /etc/sysconfig/cilium
$ sudo usermod -a -G cilium vagrant
$ sudo systemctl enable cilium
$ sudo systemctl restart cilium
Notes¶
Your Cilium tree is mapped to the VM so that you do not need to keep manually
copying files between your host and the VM. Folders are by default synced
automatically using VirtualBox Shared Folders .
You can also use NFS to access your Cilium tree from the VM by
setting the environment variable NFS (mentioned above) before running the
startup script (export NFS=1). Note that your host firewall must have a variety
of ports open. The Vagrantfile will inform you of the configuration of these addresses
and ports to enable NFS.
Note
OSX file system is by default case insensitive, which can confuse git. At the writing of this Cilium repo has no file names that would be considered referring to the same file on a case insensitive file system. Regardless, it may be useful to create a disk image with a case sensitive file system for holding your git repos.
Note
VirtualBox for OSX currently (version 5.1.22) always reports host-only networks’ prefix length as 64. Cilium needs this prefix to be 16, and the startup script will check for this. This check always fails when using VirtualBox on OSX, but it is safe to let the startup script to reset the prefix length to 16.
If for some reason, running of the provisioning script fails, you should bring the VM down before trying again:
$ vagrant halt
Packer-CI-Build¶
As part of Cilium development, we use a custom base box with a bunch of pre-installed libraries and tools that we need to enhance our daily workflow. That base box is built with Packer and it is hosted in the packer-ci-build GitHub repository.
New versions of this box can be created via Jenkins Packer Build, where new builds of the image will be pushed to Vagrant Cloud . The version of the image corresponds to the BUILD_ID environment variable in the Jenkins job. That version ID will be used in Cilium Vagrantfiles.
Changes to this image are made via contributions to the packer-ci-build
repository. Authorized GitHub users can trigger builds with a GitHub comment on
the PR containing the trigger phrase build-me-please. In case that a new box
needs to be rebased with a different branch than master, authorized developers
can run the build with custom parameters. To use a different Cilium branch in
the job go
to Build with parameters and a base branch can be set as the user needs.
This box will need to be updated when a new developer needs a new dependency that is not installed in the current version of the box, or if a dependency that is cached within the box becomes stale.
Make sure that you update vagrant box versions in test Vagrantfile
and root Vagrantfile after new box is built and tested.
Development process¶
Local Development in Vagrant Box¶
See Setting up the development environment for information on how to setup the development environment.
When the development VM is provisioned, it builds and installs Cilium. After
the initial build and install you can do further building and testing
incrementally inside the VM. vagrant ssh takes you to the Cilium source
tree directory (/home/vagrant/go/src/github.com/cilium/cilium) by default,
and the following commands assume that you are working within that directory.
Build Cilium¶
Assuming you have synced (rsync) the source tree after you have made changes, or the tree is automatically in sync via NFS or guest additions folder sharing, you can issue a build as follows:
$ make
Install to dev environment¶
After a successful build and test you can re-install Cilium by:
$ sudo -E make install
Restart Cilium service¶
To run the newly installed version of Cilium, restart the service:
$ sudo systemctl restart cilium
You can verify the service and cilium-agent status by the following commands, respectively:
$ sudo systemctl status cilium
$ cilium status
Making Changes¶
- Create a topic branch:
git checkout -b myBranch master - Make the changes you want
- Separate the changes into logical commits.
- Describe the changes in the commit messages. Focus on answering the question why the change is required and document anything that might be unexpected.
- If any description is required to understand your code changes, then those instructions should be code comments instead of statements in the commit description.
- Make sure your changes meet the following criteria:
- New code is covered by Unit Testing.
- End to end integration / runtime tests have been extended or added. If not required, mention in the commit message what existing test covers the new code.
- Follow-up commits are squashed together nicely. Commits should separate logical chunks of code and not represent a chronological list of changes.
- Run
git diff --checkto catch obvious white space violations - Run
maketo build your changes. This will also rungo fmtand error out on any golang formatting errors. - See Unit Testing on how to run unit tests.
- See End-To-End Testing Framework for information how to run the end to end integration tests
Unit Testing¶
Cilium uses the standard go test framework in combination with gocheck for richer testing functionality.
Prerequisites¶
Some tests interact with the kvstore and depend on a local kvstore instances of both etcd and consul. To start the local instances, run:
$ make start-kvstores
Running all tests¶
To run unit tests over the entire repository, run the following command in the project root directory:
$ make unit-tests
Testing individual packages¶
It is possible to test individual packages by invoking go test directly.
You can then cd into the package subject to testing and invoke go test:
$ cd pkg/kvstore
$ go test
If you need more verbose output, you can pass in the -check.v and
-check.vv arguments:
$ cd pkg/kvstore
$ go test -check.v -check.vv
If the unit tests have some prerequisites like Prerequisites, you can use the following command to automatically set up the prerequisites, run the unit tests and tear down the prerequisites:
$ make unit-tests TESTPKGS=github.com/cilium/cilium/pkg/kvstore
Running individual tests¶
Due to the use of gocheck, the standard go test -run will not work,
instead, the -check.f argument has to be specified:
$ go test -check.f TestParallelAllocation
Automatically run unit tests on code changes¶
The script contrib/shell/test.sh contains some helpful bash functions to
improve the feedback cycle between writing tests and seeing their results. If
you’re writing unit tests in a particular package, the watchtest function
will watch for changes in a directory and run the unit tests for that package
any time the files change. For example, if writing unit tests in pkg/policy,
run this in a terminal next to your editor:
$ . contrib/shell/test.sh
$ watchtest pkg/policy
This shell script depends on the inotify-tools package on Linux.
Add/update a golang dependency¶
Once you have downloaded dep make sure you have version >= 0.4.1
$ dep version
dep:
version : v0.4.1
build date : 2018-01-24
git hash : 37d9ea0a
go version : go1.9.1
go compiler : gc
platform : linux/amd64
After that, you can edit the Gopkg.toml file, add the library that you want
to add. Lets assume we want to add github.com/containernetworking/cni
version v0.5.2:
[[constraint]]
name = "github.com/containernetworking/cni"
revision = "v0.5.2"
Once you add the libraries that you need you can save the file and run
$ dep ensure -v
For a first run, it can take a while as it will download all dependencies to your local cache but the remaining runs will be faster.
Debugging¶
Datapath code¶
The tool cilium monitor can also be used to retrieve debugging information
from the BPF based datapath. Debugging messages are sent if either the
cilium-agent itself or the respective endpoint is in debug mode. The debug
mode of the agent can be enabled by starting cilium-agent with the option
--debug enabled or by running cilium config debug=true for an already
running agent. Debugging of an individual endpoint can be enabled by running
cilium endpoint config ID debug=true
$ cilium endpoint config 3978 debug=true
Endpoint 3978 configuration updated successfully
$ cilium monitor -v --hex
Listening for events on 2 CPUs with 64x4096 of shared memory
Press Ctrl-C to quit
------------------------------------------------------------------------------
CPU 00: MARK 0x1c56d86c FROM 3978 DEBUG: 70 bytes Incoming packet from container ifindex 85
00000000 33 33 00 00 00 02 ae 45 75 73 11 04 86 dd 60 00 |33.....Eus....`.|
00000010 00 00 00 10 3a ff fe 80 00 00 00 00 00 00 ac 45 |....:..........E|
00000020 75 ff fe 73 11 04 ff 02 00 00 00 00 00 00 00 00 |u..s............|
00000030 00 00 00 00 00 02 85 00 15 b4 00 00 00 00 01 01 |................|
00000040 ae 45 75 73 11 04 00 00 00 00 00 00 |.Eus........|
CPU 00: MARK 0x1c56d86c FROM 3978 DEBUG: Handling ICMPv6 type=133
------------------------------------------------------------------------------
CPU 00: MARK 0x1c56d86c FROM 3978 Packet dropped 131 (Invalid destination mac) 70 bytes ifindex=0 284->0
00000000 33 33 00 00 00 02 ae 45 75 73 11 04 86 dd 60 00 |33.....Eus....`.|
00000010 00 00 00 10 3a ff fe 80 00 00 00 00 00 00 ac 45 |....:..........E|
00000020 75 ff fe 73 11 04 ff 02 00 00 00 00 00 00 00 00 |u..s............|
00000030 00 00 00 00 00 02 85 00 15 b4 00 00 00 00 01 01 |................|
00000040 00 00 00 00 |....|
------------------------------------------------------------------------------
CPU 00: MARK 0x7dc2b704 FROM 3978 DEBUG: 86 bytes Incoming packet from container ifindex 85
00000000 33 33 ff 00 8a d6 ae 45 75 73 11 04 86 dd 60 00 |33.....Eus....`.|
00000010 00 00 00 20 3a ff fe 80 00 00 00 00 00 00 ac 45 |... :..........E|
00000020 75 ff fe 73 11 04 ff 02 00 00 00 00 00 00 00 00 |u..s............|
00000030 00 01 ff 00 8a d6 87 00 20 40 00 00 00 00 fd 02 |........ @......|
00000040 00 00 00 00 00 00 c0 a8 21 0b 00 00 8a d6 01 01 |........!.......|
00000050 ae 45 75 73 11 04 00 00 00 00 00 00 |.Eus........|
CPU 00: MARK 0x7dc2b704 FROM 3978 DEBUG: Handling ICMPv6 type=135
CPU 00: MARK 0x7dc2b704 FROM 3978 DEBUG: ICMPv6 neighbour soliciation for address b21a8c0:d68a0000
One of the most common issues when developing datapath code is that the BPF code cannot be loaded into the kernel. This frequently manifests as the endpoints appearing in the “not-ready” state and never switching out of it:
$ cilium endpoint list
ENDPOINT POLICY IDENTITY LABELS (source:key[=value]) IPv6 IPv4 STATUS
ENFORCEMENT
48896 Disabled 266 container:id.server fd02::c0a8:210b:0:bf00 10.11.13.37 not-ready
60670 Disabled 267 container:id.client fd02::c0a8:210b:0:ecfe 10.11.167.158 not-ready
Running cilium endpoint get for one of the endpoints will provide a
description of known state about it, which includes BPF verification logs.
The files under /var/run/cilium/state provide context about how the BPF
datapath is managed and set up. The .log files will describe the BPF
requirements and features that Cilium detected and used to generate the BPF
programs. The .h files describe specific configurations used for BPF program
compilation. The numbered directories describe endpoint-specific state,
including header configuration files and BPF binaries.
# for log in /var/run/cilium/state/*.log; do echo "cat $log"; cat $log; done
cat /var/run/cilium/state/bpf_features.log
BPF/probes: CONFIG_CGROUP_BPF=y is not in kernel configuration
BPF/probes: CONFIG_LWTUNNEL_BPF=y is not in kernel configuration
HAVE_LPM_MAP_TYPE: Your kernel doesn't support LPM trie maps for BPF, thus disabling CIDR policies. Recommendation is to run 4.11+ kernels.
HAVE_LRU_MAP_TYPE: Your kernel doesn't support LRU maps for BPF, thus switching back to using hash table for the cilium connection tracker. Recommendation is to run 4.10+ kernels.
Current BPF map state for particular programs is held under /sys/fs/bpf/,
and the bpf-map utility can be useful
for debugging what is going on inside them, for example:
# ls /sys/fs/bpf/tc/globals/
cilium_calls_15124 cilium_calls_48896 cilium_ct4_global cilium_lb4_rr_seq cilium_lb6_services cilium_policy_25729 cilium_policy_60670 cilium_proxy6
cilium_calls_25729 cilium_calls_60670 cilium_ct6_global cilium_lb4_services cilium_lxc cilium_policy_3978 cilium_policy_reserved_1 cilium_reserved_policy
cilium_calls_3978 cilium_calls_netdev_ns_1 cilium_events cilium_lb6_reverse_nat cilium_policy cilium_policy_4314 cilium_policy_reserved_2 cilium_tunnel_map
cilium_calls_4314 cilium_calls_overlay_2 cilium_lb4_reverse_nat cilium_lb6_rr_seq cilium_policy_15124 cilium_policy_48896 cilium_proxy4
# bpf-map info /sys/fs/bpf/tc/globals/cilium_policy_15124
Type: Hash
Key size: 8
Value size: 24
Max entries: 1024
Flags: 0x0
# bpf-map dump /sys/fs/bpf/tc/globals/cilium_policy_15124
Key:
00000000 6a 01 00 00 82 23 06 00 |j....#..|
Value:
00000000 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00000010 00 00 00 00 00 00 00 00 |........|
End-To-End Testing Framework¶
Introduction¶
Cilium uses Ginkgo as a testing framework for
writing end-to-end tests which test Cilium all the way from the API level (e.g.
importing policies, CLI) to the datapath (i.e, whether policy that is imported
is enforced accordingly in the datapath). The tests in the test directory
are built on top of Ginkgo. Ginkgo provides a rich framework for developing
tests alongside the benefits of Golang (compilation-time checks, types, etc.).
To get accustomed to the basics of Ginkgo, we recommend reading the Ginkgo
Getting-Started Guide , as
well as running example tests to get a feel for the
Ginkgo workflow.
These test scripts will invoke vagrant to create virtual machine(s) to
run the tests. The tests make heavy use of the Ginkgo focus concept to
determine which VMs are necessary to run particular tests. All test names
must begin with one of the following prefixes:
Runtime: Test cilium in a runtime environment running on a single node.K8s: Create a small multi-node kubernetes environment for testing features beyond a single host, and for testing kubernetes-specific features.Nightly: sets up a multinode Kubernetes cluster to run scale, performance, and chaos testing for Cilium.
Running End-To-End Tests¶
Running All Tests¶
Running all of the Ginkgo tests may take an hour or longer. To run all the ginkgo tests, invoke the make command as follows from the root of the cilium repository:
$ sudo make -C test/
The first time that this is invoked, the testsuite will pull the testing VMs and provision Cilium into them. This may take several minutes, depending on your internet connection speed. Subsequent runs of the test will reuse the image.
Running Runtime Tests¶
To run all of the runtime tests, execute the following command from the test directory:
ginkgo --focus="Runtime*" -noColor
Ginkgo searches for all tests in all subdirectories that are “named” beginning with the string “Runtime” and contain any characters after it. For instance, here is an example showing what tests will be ran using Ginkgo’s dryRun option:
$ ginkgo --focus="Runtime*" -noColor -v -dryRun
Running Suite: runtime
======================
Random Seed: 1516125117
Will run 42 of 164 specs
................
RuntimePolicyEnforcement Policy Enforcement Always
Always to Never with policy
/Users/ianvernon/go/src/github.com/cilium/cilium/test/runtime/Policies.go:258
•
------------------------------
RuntimePolicyEnforcement Policy Enforcement Always
Always to Never without policy
/Users/ianvernon/go/src/github.com/cilium/cilium/test/runtime/Policies.go:293
•
------------------------------
RuntimePolicyEnforcement Policy Enforcement Never
Container creation
/Users/ianvernon/go/src/github.com/cilium/cilium/test/runtime/Policies.go:332
•
------------------------------
RuntimePolicyEnforcement Policy Enforcement Never
Never to default with policy
/Users/ianvernon/go/src/github.com/cilium/cilium/test/runtime/Policies.go:349
.................
Ran 42 of 164 Specs in 0.002 seconds
SUCCESS! -- 0 Passed | 0 Failed | 0 Pending | 122 Skipped PASS
Ginkgo ran 1 suite in 1.830262168s
Test Suite Passed
The output has been truncated. For more information about this functionality, consult the aforementioned Ginkgo documentation.
Running Kubernetes Tests¶
To run all of the Kubernetes tests, run the following command from the test directory:
ginkgo --focus="K8s*" -noColor
Similar to the Runtime test suite, Ginkgo searches for all tests in all subdirectories that are “named” beginning with the string “K8s” and contain any characters after it.
The Kubernetes tests support the following Kubernetes versions:
- 1.8
- 1.9
- 1.10
- 1.11
- 1.12
- 1.13
- 1.14
- 1.15
By default, the Vagrant VMs are provisioned with Kubernetes 1.13. To run with any other supported version of Kubernetes, run the test suite with the following format:
K8S_VERSION=<version> ginkgo --focus="K8s*" -noColor
Note
When provisioning VMs with the net-next kernel (NETNEXT=true) on
VirtualBox which version does not match a version of the VM image
VirtualBox Guest Additions, Vagrant will install a new version of
the Additions with mount.vboxsf. The latter is not compatible with
vboxsf.ko shipped within the VM image, and thus syncing of shared
folders will not work.
To avoid this, one can prevent Vagrant from installing the Additions by
putting the following into $HOME/.vagrant.d/Vagrantfile:
Vagrant.configure('2') do |config|
if Vagrant.has_plugin?("vagrant-vbguest") then
config.vbguest.auto_update = false
end
config.vm.provider :virtualbox do |vbox|
vbox.check_guest_additions = false
end
end
Running Nightly Tests¶
To run all of the Nightly tests, run the following command from the test directory:
ginkgo --focus="Nightly*" -noColor
Similar to the other test suites, Ginkgo searches for all tests in all
subdirectories that are “named” beginning with the string “Nightly” and contain
any characters after it. The default version of running Nightly test are 1.8,
but can be changed using the environment variable K8S_VERSION.
Available CLI Options¶
For more advanced workflows, check the list of available custom options for the Cilium
framework in the test/ directory and interact with ginkgo directly:
$ cd test/
$ ginkgo . -- --help | grep -A 1 cilium
-cilium.SSHConfig string
Specify a custom command to fetch SSH configuration (eg: 'vagrant ssh-config')
-cilium.holdEnvironment
On failure, hold the environment in its current state
-cilium.provision
Provision Vagrant boxes and Cilium before running test (default true)
-cilium.showCommands
Output which commands are ran to stdout
-cilium.testScope string
Specifies scope of test to be ran (k8s, Nightly, runtime)
$ ginkgo --focus "Policies*" -- --cilium.provision=false
For more information about other built-in options to Ginkgo, consult the Ginkgo documentation.
Running Specific Tests Within a Test Suite¶
If you want to run one specified test, there are a few options:
- By modifying code: add the prefix “FIt” on the test you want to run; this marks the test as focused. Ginkgo will skip other tests and will only run the “focused” test. For more information, consult the Focused Specs documentation from Ginkgo.
It("Example test", func(){
Expect(true).Should(BeTrue())
})
FIt("Example focused test", func(){
Expect(true).Should(BeTrue())
})
- From the command line: specify a more granular focus if you want to focus on, say, L7 tests:
ginkgo --focus "Run*" --focus "L7 "
This will focus on tests prefixed with “Run*”, and within that focus, run any test that starts with “L7”.
Test Reports¶
The Cilium Ginkgo framework formulates JUnit reports for each test. The following files currently are generated depending upon the test suite that is ran:
- runtime.xml
- K8s.xml
Best Practices for Writing Tests¶
- Provide informative output to console during a test using the By construct. This helps with debugging and gives those who did not write the test a good idea of what is going on. The lower the barrier of entry is for understanding tests, the better our tests will be!
- Leave the testing environment in the same state that it was in when the test started by deleting resources, resetting configuration, etc.
- Gather logs in the case that a test fails. If a test fails while running on Jenkins, a postmortem needs to be done to analyze why. So, dumping logs to a location where Jenkins can pick them up is of the highest imperative. Use the following code in an
AfterFailedmethod:
AfterFailed(func() {
vm.ReportFailed()
})
Ginkgo Extensions¶
In Cilium, some Ginkgo features are extended to cover some uses cases that are useful for testing Cilium.
BeforeAll¶
This function will run before all BeforeEach within a
Describe or Context.
This method is an equivalent to SetUp or initialize functions in common
unit test frameworks.
AfterAll¶
This method will run after all AfterEach functions
defined in a Describe or Context.
This method is used for tearing down objects created which are used by all
Its within the given Context or Describe. It is ran after all Its
have ran, this method is a equivalent to tearDown or finalize methods in
common unit test frameworks.
A good use case for using AfterAll method is to remove containers or pods
that are needed for multiple Its in the given Context or Describe.
JustAfterEach¶
This method will run just after each test and before AfterFailed and
AfterEach. The main reason of this method is to to perform some assertions
for a group of tests. A good example of using a global JustAfterEach
function is for deadlock detection, which checks the Cilium logs for deadlocks
that may have occurred in the duration of the tests.
AfterFailed¶
This method will run before all AfterEach and after JustAfterEach. This
function is only called when the test failed.This construct is used to gather
logs, the status of Cilium, etc, which provide data for analysis when tests
fail.
Example Test Layout¶
Here is an example layout of how a test may be written with the aforementioned constructs:
Test description diagram:
Describe
BeforeAll(A)
AfterAll(A)
AfterFailed(A)
AfterEach(A)
JustAfterEach(A)
TESTA1
TESTA2
TESTA3
Context
BeforeAll(B)
AfterAll(B)
AfterFailed(B)
AfterEach(B)
JustAfterEach(B)
TESTB1
TESTB2
TESTB3
Test execution flow:
Describe
BeforeAll
TESTA1; JustAfterEach(A), AfterFailed(A), AfterEach(A)
TESTA2; JustAfterEach(A), AfterFailed(A), AfterEach(A)
TESTA3; JustAfterEach(A), AfterFailed(A), AfterEach(A)
Context
BeforeAll(B)
TESTB1:
JustAfterEach(B); JustAfterEach(A)
AfterFailed(B); AfterFailed(A);
AfterEach(B) ; AfterEach(A);
TESTB2:
JustAfterEach(B); JustAfterEach(A)
AfterFailed(B); AfterFailed(A);
AfterEach(B) ; AfterEach(A);
TESTB3:
JustAfterEach(B); JustAfterEach(A)
AfterFailed(B); AfterFailed(A);
AfterEach(B) ; AfterEach(A);
AfterAll(B)
AfterAll(A)
Debugging:¶
Ginkgo provides to us different ways of debugging. In case that you want to see
all the logs messages in the console you can run the test in verbose mode using
the option -v:
ginkgo --focus "Runtime*" -v
In case that the verbose mode is not enough, you can retrieve all run commands
and their output in the report directory (./test/test_results). Each test
creates a new folder, which contains a file called log where all information is
saved, in case of a failing test an exhaustive data will be added.
$ head test/test_results/RuntimeKafkaKafkaPolicyIngress/logs
level=info msg=Starting testName=RuntimeKafka
level=info msg="Vagrant: running command \"vagrant ssh-config runtime\""
cmd: "sudo cilium status" exitCode: 0
KVStore: Ok Consul: 172.17.0.3:8300
ContainerRuntime: Ok
Kubernetes: Disabled
Kubernetes APIs: [""]
Cilium: Ok OK
NodeMonitor: Disabled
Allocated IPv4 addresses:
Running with delve¶
Delve is a debugging tool for Go
applications. If you want to run your test with delve, you should add a new
breakpoint using
runtime.BreakPoint() in the
code, and run ginkgo using dlv.
Example how to run ginkgo using dlv:
dlv test . -- --ginkgo.focus="Runtime" -ginkgo.v=true --cilium.provision=false
Running End-To-End Tests In Other Environments¶
If you want to run tests in a different VM, you can use --cilium.SSHConfig to
provide the SSH configuration of the endpoint on which tests will be ran. The
tests presume the following on the remote instance:
- Cilium source code is located in the directory
/home/vagrant/go/src/github.com/cilium/cilium/. - Cilium is installed and running.
The ssh connection needs to be defined as a ssh-config file and need to have
the following targets:
- runtime: To run runtime tests
- k8s{1..2}-${K8S_VERSION}: to run Kubernetes tests. These instances must have Kubernetes installed and running as a prerequisite for running tests.
An example ssh-config can be the following:
Host runtime
HostName 127.0.0.1
User vagrant
Port 2222
UserKnownHostsFile /dev/null
StrictHostKeyChecking no
PasswordAuthentication no
IdentityFile /home/eloy/.go/src/github.com/cilium/cilium/test/.vagrant/machines/runtime/virtualbox/private_key
IdentitiesOnly yes
LogLevel FATAL
To run this you can use the following command:
ginkgo -v -- --cilium.provision=false --cilium.SSHConfig="cat ssh-config"
VMs for Testing¶
The VMs used for testing are defined in test/Vagrantfile. There are a variety of
configuration options that can be passed as environment variables:
| ENV variable | Default Value | Options | Description |
|---|---|---|---|
| K8S_NODES | 2 | 0..100 | Number of Kubernetes nodes in the cluster |
| NFS | 0 | 1 | If Cilium folder needs to be shared using NFS |
| IPv6 | 0 | 0-1 | If 1 the Kubernetes cluster will use IPv6 |
| CONTAINER_RUNTIME | docker | containerd | To set the default container runtime in the Kubernetes cluster |
| K8S_VERSION | 1.13 | 1.** | Kubernetes version to install |
| SERVER_BOX | cilium/ubuntu-dev | Vagrantcloud base image | |
| CPU | 2 | 0..100 | Number of CPUs that need to have the VM |
| MEMORY | 4096 | d+ | RAM size in Megabytes |
How to contribute¶
Getting Started¶
Make sure you have a GitHub account
Clone the cilium repository
go get -d github.com/cilium/cilium cd $GOPATH/src/github.com/cilium/cilium
Set up your Setting up the development environment
Check the GitHub issues for good tasks to get started.
Submitting a pull request¶
Contributions must be submitted in the form of pull requests against the github repository at: https://github.com/cilium/cilium
- Fork the Cilium repository to your own personal GitHub space or request access to a Cilium developer account on Slack
- Push your changes to the topic branch in your fork of the repository.
- Submit a pull request on https://github.com/cilium/cilium.
Before hitting the submit button, please make sure that the following requirements have been met:
Each commit compiles and is functional on its own to allow for bisecting of commits.
All code is covered by unit and/or runtime tests where feasible.
All changes have been tested and checked for regressions by running the existing testsuite against your changes. See the End-To-End Testing Framework section for additional details.
All commits contain a well written commit description including a title, description and a
Fixes: #XXXline if the commit addresses a particular GitHub issue. Note that the GitHub issue will be automatically closed when the commit is merged.apipanic: Log stack at debug level Previously, it was difficult to debug issues when the API panicked because only a single line like the following was printed: level=warning msg="Cilium API handler panicked" client=@ method=GET panic_message="write unix /var/run/cilium/cilium.sock->@: write: broken pipe" This patch logs the stack at this point at debug level so that it can at least be determined in developer environments. Fixes: #4191 Signed-off-by: Joe Stringer <joe@covalent.io>
If any of the commits fixes a particular commit already in the tree, that commit is referenced in the commit message of the bugfix. This ensures that whoever performs a backport will pull in all required fixes:
daemon: use endpoint RLock in HandleEndpoint Fixes: a804c7c7dd9a ("daemon: wait for endpoint to be in ready state if specified via EndpointChangeRequest") Signed-off-by: André Martins <andre@cilium.io>
All commits are signed off. See the section Developer’s Certificate of Origin.
Pick the appropriate milestone for which this PR is being targeted to, e.g.
1.1,1.2. This is in particular important in the time frame between the feature freeze and final release date.Pick the right release-note label
Labels When to set release-note/bugThis is a non-trivial bugfix release-note/majorThis is a major feature addition, e.g. Add MongoDB support release-note/minorThis is a minor feature addition, e.g. Refactor endpoint package Verify the release note text. If not explicitly changed, the title of the PR will be used for the release notes. If you want to change this, you can add a special section to the description of the PR.
```release-note This is a release note text ```
Note
If multiple lines are provided, then the first line serves as the high level bullet point item and any additional line will be added as a sub item to the first line.
Pick the right labels for your PR:
Labels When to set kind/bugThis is a bugfix worth mentioning in the release notes kind/enhancementThis is an enhancement/feature priority/release-blockerThis PR should block the current release area/*Code area this PR covers needs-backport/X.YPR needs to be backported to these stable releases pending-reviewPR is immediately ready for review wipPR is still work in progress, signals reviewers to hold. backport/X.YThis is backport PR, may only be set as part of Backporting process upgrade-impactThe code changes have a potential upgrade impact
Getting a pull request merged¶
- As you submit the pull request as described in the section Submitting a pull request.
One of the reviewers will start a CI run by replying with a comment
test-me-pleaseas described in Triggering Pull-Request Builds With Jenkins. If you are a core team member, you may trigger the CI run yourself.- Hound: basic
golang/lintstatic code analyzer. You need to make the puppy happy. - CI / Jenkins: Will run a series of tests:
- Unit tests
- Single node runtime tests
- Multi node Kubernetes tests
- Hound: basic
- As part of the submission, GitHub will have requested a review from the
respective code owners according to the
CODEOWNERSfile in the repository.- Address any feedback received from the reviewers
- You can push individual commits to address feedback and then rebase your branch at the end before merging.
- Owners of the repository will automatically adjust the labels on the pull request to track its state and progress towards merging.
- Once the PR has been reviewed and the CI tests have passed, the PR will be merged by one of the repository owners. In case this does not happen, ping us on Slack.
Pull request review process¶
Note
These instructions assume that whoever is reviewing is a member of the Cilium GitHub organization or has the status of a contributor. This is required to obtain the privileges to modify GitHub labels on the pull request.
Review overall correctness of the PR according to the rules specified in the section Submitting a pull request.
Set the label accordingly.
Labels When to set dont-merge/needs-sign-offSome commits are not signed off needs-rebasePR is outdated and needs to be rebased As soon as a PR has the label
pending-review, review the code and request changes as needed by using the GitHubRequest Changesfeature or by using Reviewable.Validate that bugfixes are marked with
kind/bugand validate whether the assessment of backport requirements as requested by the submitter conforms to the Stable releases process.Labels When to set needs-backport/X.YPR needs to be backported to these stable releases If the PR is subject to backport, validate that the PR does not mix bugfix and refactoring of code as it will heavily complicate the backport process. Demand for the PR to be split.
Validate the
release-note/*label and check the PR title for release note suitability. Put yourself into the perspective of a future release notes reader with lack of context and ensure the title is precise but brief.Labels When to set dont-merge/needs-release-noteDo NOT merge PR, needs a release note release-note/bugThis is a non-trivial bugfix release-note/majorThis is a major feature addition release-note/minorThis is a minor feature addition Check for upgrade compatibility impact and if in doubt, set the label
upgrade-impactand discuss in the Slack channel.Labels When to set upgrade-impactThe code changes have a potential upgrade impact When everything looks OK, approve the changes.
When all review objectives for all
CODEOWNERSare met and all CI tests have passed, you may set theready-to-mergelabel to indicate that all criteria have been met.Labels When to set ready-to-mergePR is ready to be merged
Building Container Images¶
Two make targets exists to build container images automatically based on the locally checked out branch:
Developer images¶
DOCKER_IMAGE_TAG=jane-developer-my-fix make dev-docker-image
You can then push the image tag to the registry for development builds:
docker push cilium/cilium-dev:jane-developer-my-fix
Access to the developer builds registry is restricted but access is granted liberally. Join the #development channel in Slack and ask for permission to push builds.
Official release images¶
Anyone can build official release images using the make target below but pushing to the official registries is restricted to Cilium maintainers. Ask in the #launchpad Slack channels for the exact details.
DOCKER_IMAGE_TAG=v1.4.0 make docker-image
You can then push the image tag to the registry:
docker push cilium/cilium:v1.4.0
Documentation¶
Building¶
The documentation has several dependencies which can be installed using pip:
$ pip install -r Documentation/requirements.txt
Whenever making changes to Cilium documentation you should check that you did not introduce any new warnings or errors, and also check that your changes look as you intended. To do this you can build the docs:
$ make -C Documentation html
After this you can browse the updated docs as HTML starting at
Documentation\_build\html\index.html.
Alternatively you can use a Docker container to build the pages:
$ make render-docs
This builds the docs in a container and builds and starts a web server with your document changes.
Now the documentation page should be browsable on http://localhost:9080.
CI / Jenkins¶
The main CI infrastructure is maintained at https://jenkins.cilium.io/
Jobs Overview¶
Cilium-PR-Ginkgo-Tests-Validated¶
Runs validated Ginkgo tests which are confirmed to be stable and have been verified. These tests must always pass.
The configuration for this job is contained within ginkgo.Jenkinsfile.
It first runs unit tests using docker-compose using a YAML located at
test/docker-compose.yaml.
The next steps happens in parallel:
- Runs the single-node e2e tests using the Docker runtime.
- Runs the multi-node Kubernetes e2e tests against the latest default version of Kubernetes specified above.
Cilium-PR-Ginkgo-Tests-k8s¶
Runs the Kubernetes e2e tests against all Kubernetes versions that are not currently not tested as part of each pull-request, but which Cilium still supports, as well as the the most-recently-released versions of Kubernetes that that might not be declared stable by Kubernetes upstream:
First stage.
- 1.10
- 1.11
Second stage (other versions)
- 1.12
- 1.13
Third stage
- 1.14
- beta versions (1.16-beta once it’s out)
Ginkgo-CI-Tests-Pipeline¶
Cilium-Nightly-Tests-PR¶
Runs long-lived tests which take extended time. Some of these tests have an expected failure rate.
Nightly tests run once per day in the Cilium-Nightly-Tests Job. The
configuration for this job is stored in Jenkinsfile.nightly.
To see the results of these tests, you can view the JUnit Report for an individual job:
- Click on the build number you wish to get test results from on the left hand side of the Cilium-Nightly-Tests Job.
- Click on ‘Test Results’ on the left side of the page to view the results from the build. This will give you a report of which tests passed and failed. You can click on each test to view its corresponding output created from Ginkgo.
This first runs the Nightly tests with the following setup:
- 4 Kubernetes 1.8 nodes
- 4 GB of RAM per node.
- 4 vCPUs per node.
Then, it runs tests Kubernetes tests against versions of Kubernetes that are currently not tested against as part of each pull-request, but that Cilium still supports.
It also runs a variety of tests against Envoy to ensure that proxy functionality is working correctly.
Triggering Pull-Request Builds With Jenkins¶
To ensure that build resources are used judiciously, builds on Jenkins are manually triggered via comments on each pull-request that contain “trigger-phrases”. Only members of the Cilium GitHub organization are allowed to trigger these jobs. Refer to the table below for information regarding which phrase triggers which build, which build is required for a pull-request to be merged, etc. Each linked job contains a description illustrating which subset of tests the job runs.
| Jenkins Job | Trigger Phrase | Required To Merge? |
|---|---|---|
| Cilium-PR-Ginkgo-Tests-Validated | test-me-please | Yes |
| Cilium-Pr-Ginkgo-Test-k8s | test-missed-k8s | No |
| Cilium-Nightly-Tests-PR | test-nightly | No |
| Cilium-PR-Doc-Tests | test-docs-please | No |
| Cilium-PR-Kubernetes-Upstream | test-upstream-k8s | No |
| Cilium-PR-Flannel | test-flannel | No |
There are some feature flags based on Pull Requests labels, the list of labels are the following:
area/containerd: Enable containerd runtime on all Kubernetes test.ci/next-next: Run tests on net-next kernel. This causes thetest-me-pleasetarget to only run on the net-next kernel. It is purely for testing on a different kernel, to merge a PR it must pass the CI without this flag.
Using Jenkins for testing¶
Typically when running Jenkins tests via one of the above trigger phases, it will run all of the tests in that particular category. However, there may be cases where you just want to run a single test quickly on Jenkins and observe the test result. To do so, you need to update the relevant test to have a custom name, and to update the Jenkins file to focus that test. Below is an example patch that shows how this can be achieved.
diff --git a/ginkgo.Jenkinsfile b/ginkgo.Jenkinsfile
index ee17808748a6..637f99269a41 100644
--- a/ginkgo.Jenkinsfile
+++ b/ginkgo.Jenkinsfile
@@ -62,10 +62,10 @@ pipeline {
steps {
parallel(
"Runtime":{
- sh 'cd ${TESTDIR}; ginkgo --focus="RuntimeValidated*" -v -noColor'
+ sh 'cd ${TESTDIR}; ginkgo --focus="XFoooo*" -v -noColor'
},
"K8s-1.9":{
- sh 'cd ${TESTDIR}; K8S_VERSION=1.9 ginkgo --focus=" K8sValidated*" -v -noColor ${FAILFAST}'
+ sh 'cd ${TESTDIR}; K8S_VERSION=1.9 ginkgo --focus=" K8sFooooo*" -v -noColor ${FAILFAST}'
},
failFast: true
)
diff --git a/test/k8sT/Nightly.go b/test/k8sT/Nightly.go
index 62b324619797..3f955c73a818 100644
--- a/test/k8sT/Nightly.go
+++ b/test/k8sT/Nightly.go
@@ -466,7 +466,7 @@ var _ = Describe("NightlyExamples", func() {
})
- It("K8sValidated Updating Cilium stable to master", func() {
+ FIt("K8sFooooo K8sValidated Updating Cilium stable to master", func() {
podFilter := "k8s:zgroup=testapp"
//This test should run in each PR for now.
CI Failure Triage¶
This section describes the process to triage CI failures. We define 3 categories:
| Keyword | Description |
|---|---|
| Flake | Failure due to a temporary situation such as loss of connectivity to external services or bug in system component, e.g. quay.io is down, VM race conditions, kube-dns bug, … |
| CI-Bug | Bug in the test itself that renders the test unreliable, e.g. timing issue when importing and missing to block until policy is being enforced before connectivity is verified. |
| Regression | Failure is due to a regression, all failures in the CI that are not caused by bugs in the test are considered regressions. |
Pipelines subject to triage¶
Build/test failures for the following Jenkins pipelines must be reported as GitHub issues using the process below:
| Pipeline | Description |
|---|---|
| Ginkgo-Tests-Validated-master | Runs whenever a PR is merged into master |
| Ginkgo-CI-Tests-Pipeline | Runs every two hours on the master branch |
| Master-Nightly | Runs durability tests every night |
| Vagrant-Master-Boxes-Packer-Build | Runs on merge into github.com/cilium/packer-ci-build. |
| Release-branch | Runs various Ginkgo tests on merge into branch “v1.5” |
Triage process¶
Discover untriaged Jenkins failures via the jenkins-failures.sh script. It defaults to checking the previous 24 hours but this can be modified by setting the SINCE environment variable (it is a unix timestamp). The script checks the various test pipelines that need triage.
$ contrib/scripts/jenkins-failures.sh
Note
You can quickly assign SINCE with statements like
SINCE=`date -d -3days`Investigate the failure you are interested in and determine if it is a CI-Bug, Flake, or a Regression as defined in the table above.
Search GitHub issues to see if bug is already filed. Make sure to also include closed issues in your search as a CI issue can be considered solved and then re-appears. Good search terms are:
The test name, e.g.
k8s-1.7.K8sValidatedKafkaPolicyTest Kafka Policy Tests KafkaPolicies (from (k8s-1.7.xml))
The line on which the test failed, e.g.
github.com/cilium/cilium/test/k8sT/KafkaPolicies.go:202
The error message, e.g.
Failed to produce from empire-hq on topic deathstar-plan
If a corresponding GitHub issue exists, update it with:
- A link to the failing Jenkins build (note that the build information is eventually deleted).
- Attach the zipfile downloaded from Jenkins with logs from the failing tests. A zipfile for all tests is also available.
- Check how much time has passed since the last reported occurrence of this failure and move this issue to the correct column in the CI flakes project board.
If no existing GitHub issue was found, file a new GitHub issue:
- Attach zipfile downloaded from Jenkins with logs from failing test
- If the failure is a new regression or a real bug:
- Title:
<Short bug description> - Labels
kind/bugandneeds/triage.
- Title:
- If failure is a new CI-Bug, Flake or if you are unsure:
- Title
CI: <testname>: <cause>, e.g.CI: K8sValidatedPolicyTest Namespaces: cannot curl service - Labels
kind/bug/CIandneeds/triage - Include a link to the failing Jenkins build (note that the build information is eventually deleted).
- Attach zipfile downloaded from Jenkins with logs from failing test
- Include the test name and whole Stacktrace section to help others find this issue.
- Add issue to CI flakes project
- Title
Note
Be extra careful when you see a new flake on a PR, and want to open an issue. It’s much more difficult to debug these without context around the PR and the changes it introduced. When creating an issue for a PR flake, include a description of the code change, the PR, or the diff. If it isn’t related to the PR, then it should already happen in master, and a new issue isn’t needed.
Edit the description of the Jenkins build to mark it as triaged. This will exclude it from future jenkins-failures.sh output.
- Login -> Click on build -> Edit Build Information
- Add the failure type and GH issue number. Use the table describing the failure categories, at the beginning of this section, to help categorize them.
Note
This step can only be performed with an account on Jenkins. If you are interested in CI failure reviews and do not have an account yet, ping us on Slack.
Examples:
Flake, quay.io is downFlake, DNS not ready, #3333CI-Bug, K8sValidatedPolicyTest: Namespaces, pod not ready, #9939Regression, k8s host policy, #1111
Infrastructure details¶
Logging into VM running tests¶
- If you have access to credentials for Jenkins, log into the Jenkins slave running the test workload
- Identify the vagrant box running the specific test
$ vagrant global-status
id name provider state directory
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------
6e68c6c k8s1-build-PR-1588-6 virtualbox running /root/jenkins/workspace/cilium_cilium_PR-1588-CWL743UTZEF6CPEZCNXQVSZVEW32FR3CMGKGY6667CU7X43AAZ4Q/tests/k8s
ec5962a cilium-master-build-PR-1588-6 virtualbox running /root/jenkins/workspace/cilium_cilium_PR-1588-CWL743UTZEF6CPEZCNXQVSZVEW32FR3CMGKGY6667CU7X43AAZ4Q
bfaffaa k8s2-build-PR-1588-6 virtualbox running /root/jenkins/workspace/cilium_cilium_PR-1588-CWL743UTZEF6CPEZCNXQVSZVEW32FR3CMGKGY6667CU7X43AAZ4Q/tests/k8s
3fa346c k8s1-build-PR-1588-7 virtualbox running /root/jenkins/workspace/cilium_cilium_PR-1588-CWL743UTZEF6CPEZCNXQVSZVEW32FR3CMGKGY6667CU7X43AAZ4Q@2/tests/k8s
b7ded3c cilium-master-build-PR-1588-7 virtualbox running /root/jenkins/workspace/cilium_cilium_PR-1588-CWL743UTZEF6CPEZCNXQVSZVEW32FR3CMGKGY6667CU7X43AAZ4Q@2
- Log into the specific VM
$ JOB_BASE_NAME=PR-1588 BUILD_NUMBER=6 vagrant ssh 6e68c6c
Jenkinsfiles Extensions¶
Cilium uses a custom Jenkins helper library to gather metadata from PRs and simplify our Jenkinsfiles. The exported methods are:
- ispr(): return true if the current build is a PR.
- setIfPr(string, string): return the first argument in case of a PR, if not a PR return the second one.
- BuildIfLabel(String label, String Job): trigger a new Job if the PR has that specific Label.
- Status(String status, String context): set pull request check status on
the given context, example
Status("SUCCESS", "$JOB_BASE_NAME")
Release Management¶
This section describes the release cadence and all release related processes.
Release Cadence¶
Cilium schedules a minor release every 6 weeks. Each minor release is performed
by incrementing the Y in the version format X.Y.Z. The group of
committers can decide to increment X instead to mark major milestones in
which case Y is reset to 0.
Stable releases¶
The committers can nominate PRs merged into master as required for backport
into the stable release branches. Upon necessity, stable releases are published
with the version X.Y.Z+1. Stable releases are regularly released in high
frequency or on demand to address major incidents.
In order to guarantee stable production usage while maintaining a high release cadence, the following stable releases will be maintained:
- Stable backports into the last two releases
- LTS release for extended long term backport coverage
Backport criteria for X.Y.Z+n¶
Criteria for the inclusion into latest stable release branch, i.e. what goes
into v1.1.x before v1.2.0 has been released:
- All bugfixes
Backport criteria for X.Y-1.Z¶
Criteria for the inclusion into the stable release branch of the previous
release, i.e. what goes into v1.0.x, before v1.2.0 has been released:
- Security relevant fixes
- Major bugfixes relevant to the correct operation of Cilium
LTS¶
The group of committers nominates a release to be a long term stable release. Such releases are guaranteed to receive backports for major and security relevant bugfixes. LTS releases will be declared end of life after 6 months. The group of committers will nominate and start supporting a new LTS release before the current LTS expires. If for some reason, no release can be declared LTS before the current LTS release expires, the current LTS lifetime will be extended.
Given the current 6 weeks release cadence, the development teams will aim at declaring every 3rd release to be an LTS to guarantee enough time overlap between LTS release.
Current LTS releases¶
| Release | Original Release Date | Scheduled End of Life |
|---|---|---|
| 1.0 | 2018-04-24 | 2018-10-24 |
Generic Release Process¶
This process applies to all releases other than minor releases, this includes:
- Stable releases
- Release candidates
If you intent to release a new minor release, see the Minor Release Process section instead.
Note
The following commands have been validated when ran in the VM used in the Cilium development process. See Setting up the development environment for detailed instructions about setting up said VM.
Ensure that the necessary backports have been completed and merged. See Backporting process.
Checkout the desired stable branch and pull it:
git checkout v1.0; git pull
Create a branch for the release pull request:
git checkout -b pr/prepare-v1.0.3
Update the
VERSIONfile to representX.Y.Z+1If this is the first release after creating a new release branch. Adjust the image pull policy for all
.sedfiles inexamples/kubernetesfromAlwaystoIfNotPresent.Update the image tag versions in the examples:
make -C examples/kubernetes clean all
Update the
cilium_versionandcilium_tagvariables inexamples/getting-started/VagrantfileUpdate the
AUTHORS filemake update-authors
Note
Check to see if the
AUTHORSfile has any formatting errors (for instance, indentation mismatches) as well as duplicate contributor names, and correct them accordingly.Generate the release notes by running the instructions provided in github.com/cilium/release
Add the generated release notes in the
CHANGELOG.mdfileAdd all modified files using
git addand create a pull request with the titlePrepare for release v1.0.3. Add the backport label to the PR which corresponds to the branch for which the release is being performed, e.g.backport/1.0.Note
Make sure to create the PR against the desired stable branch. In this case
v1.0Follow standard procedures to get the aforementioned PR merged into the desired stable branch. See Submitting a pull request for more information about this process.
Checkout out the stable branch and pull your merged changes:
git checkout v1.0; git pull
Create release tags:
git tag -a v1.0.3 -m 'Release v1.0.3' git tag -a 1.0.3 -m 'Release 1.0.3'
Note
There are two tags that correspond to the same release because GitHub recommends using
vx.y.zfor release version formatting, and ReadTheDocs, which hosts the Cilium documentation, requires the version to be in formatx.y.zFor more information about how ReadTheDocs does versioning, you can read their Versions Documentation.Build the binaries and push it to the release bucket:
DOMAIN=releases.cilium.io ./contrib/release/uploadrev v1.0.3
This step will print a markdown snippet which you will need when crafting the GitHub release so make sure to keep it handy.
Build the container images and push them
DOCKER_IMAGE_TAG=v1.0.3 make docker-image docker push cilium/cilium:v1.0.3
Push the git release tag
git push --tags
-
- Choose the correct target branch, e.g.
v1.0 - Choose the correct target tag, e.g.
v1.0.3 - Title:
1.0.3 - Check the
This is a pre-releasebox if you are releasing a release candidate. - Fill in the release description with the output generated by github.com/cilium/release
- Preview the description and then publish the release
- Choose the correct target branch, e.g.
Announce the release in the
#generalchannel on SlackBump the version of Cilium used in the Cilium upgrade tests to use the new release
Please reach out on the
#developmentchannel on Slack for assistance with this task.
Minor Release Process¶
On Freeze date¶
Fork a new release branch from master:
git checkout master; git pull git checkout -b v1.2 git push
Protect the branch using the GitHub UI to disallow direct push and require merging via PRs with proper reviews.
Replace the contents of the
CODEOWNERSfile with the following to reduce code reviews to essential approvals:* @cilium/janitors api/ @cilium/api pkg/apisocket/ @cilium/api pkg/monitor/payload @cilium/api pkg/policy/api/ @cilium/api pkg/proxy/accesslog @cilium/api
Commit changes, open a pull request against the new
v1.2branch, and get the pull request mergedgit checkout -b pr/prepare-v1.2 git add [...] git commit git push
Follow the Generic Release Process to release
v1.2.0-rc1.Create the following GitHub labels:
backport-pending/1.2backport-done/1.2backport/1.2needs-backport/1.2
Prepare the master branch for the next development cycle:
git checkout master; git pull
Update the
VERSIONfile to containv1.2.90Add the
VERSIONfile usinggit addand create & merge a PR titledPrepare for 1.3.0 development.- Update the release branch on
Jenkins to be tested on every change and Nightly.
(Only 1.0 minor releases) Tag newest 1.0.x Docker image as
v1.0-stableand push it to Docker Hub. This will ensure that Kops uses latest 1.0 release by default.
For the final release¶
- Follow the Generic Release Process to create the final replace and replace
X.Y.0-rcXwithX.Y.0.
Backporting process¶
Cilium PRs that are marked with the label needs-backport/X.Y need to be
backported to the stable branch X.Y. The following steps summarize
the process for backporting these PRs.
Make sure the Github labels are up-to-date, as this process will deal with all commits from PRs that have the
needs-backport/X.Ylabel set (for a stable release version X.Y). If any PRs contain labels such asbackport-pending/X.Y, ensure that the backport for that PR have been merged and if so, change the label tobackport-done/X.Y.The scripts referred to below need to be run in Linux, they do not work on OSX. You can use the cilium dev VM for this, but you need to configure git to have your name and email address to be used in the commit messages:
$ git config --global user.name "John Doe" $ git config --global user.email johndoe@example.comMake sure you have your a GitHub developer access token available. For details, see contrib/backporting/README.md
Fetch the repo, e.g.,
git fetchCheck a new branch for your backports based on the stable branch for that version, e.g.,
git checkout -b pr/v1.0-backport-YY-MM-DD origin/v1.0Run the
check-stablescript, referring to your Github access token, this will list the commits that need backporting, from the newest to oldest:$ GITHUB_TOKEN=xxx contrib/backporting/check-stable 1.0
Note
contrib/backporting/check-stableaccepts a second argument to specify a path to write a nicely-formatted pull request message to. This can be used alongside Github command-line tools to send the pull request from the command line in steps 9-10 viagh pull-request -b vX.Y -l backport/vX.Y -F <path>.Cherry-pick the commits using the master git SHAs listed, starting from the oldest (bottom), working your way up and fixing any merge conflicts as they appear. Note that for PRs that have multiple commits you will want to check that you are cherry-picking oldest commits first. The
cherry-pickscript accepts multiple arguments, in which case it will attempt to apply each commit in the order specified on the command line until one cherry pick fails or every commit is cherry-picked.$ contrib/backporting/cherry-pick <oldest-commit-sha> ... $ contrib/backporting/cherry-pick <newest-commit-sha>
Push your backports branch to cilium repo, e.g.,
git push -u origin pr/v1.0-backports-YY-MM-DDIn Github, create a new PR from your branch towards the feature branch you are backporting to. Note that by default Github creates PRs against the master branch, so you will need to change it.
Label the new backport PR with the backport label for the stable branch such as
backport/X.Yso that it is easy to find backport PRs later.Mark all PRs you backported with the backport pending label
backport-pending/X.Yand clear theneeds-backport/vX.Ylabel. This can be via the GitHub interface, or using the backport scriptcontrib/backporting/set-labels.py, e.g.:# Set PR 1234's v1.0 backporting labels to pending $ contrib/backporting/set-labels.py 1234 pending 1.0
Note
contrib/backporting/set-labels.pyrequires Python 3 and PyGithub installed.After the backport PR is merged, mark all backported PRs with
backport-done/X.Ylabel and clear thebackport-pending/X.Ylabel(s).# Set PR 1234's v1.0 backporting labels to done contrib/backporting/set-labels.py 1234 done 1.0.
Update cilium-builder and cilium-runtime images¶
Login to quay.io with your credentials to the repository that you want to update:
cilium-builder - contains Cilium build-time dependencies cilium-runtime - contains Cilium run-time dependencies
- After login, select the tab “builds” on the left menu.
- Click on the wheel.
- Enable the trigger for that build trigger.
- Confirm that you want to enable the trigger.
- After enabling the trigger, click again on the wheel.
- And click on “Run Trigger Now”.
- A new pop-up will appear and you can select the branch that contains your changes.
- Select the branch that contains the new changes.
- After selecting your branch click on “Start Build”.
- Once the build has started you can disable the Build trigger by clicking on the wheel.
- And click on “Disable Trigger”.
- Confirm that you want to disable the build trigger.
- Once the build is finished click under Tags (on the left menu).
- Click on the wheel and;
- Add a new tag to the image that was built.
- Write the name of the tag that you want to give for the newly built image.
- Confirm the name is correct and click on “Create Tag”.
- After the new tag was created you can delete the other tag, which is the name of your branch. Select the tag name.
- Click in Actions.
- Click in “Delete Tags”.
- Confirm that you want to delete tag with your branch name.
You have created a new image build with a new tag. The next steps should be to
update the repository root’s Dockerfile so that it points to the new
cilium-builder or cilium-runtime image recently created.
- Update the versions of the images that are pulled into the CI VMs.
- Open a PR against the Packer-CI-Build with an update to said image versions. Once your PR is merged, a new version of the VM will be ready for consumption in the CI.
- Update the
SERVER_VERSIONfield intest/Vagrantfileto contain the new version, which is the build number from the Jenkins Job for the VMs. For example, build 119 from the pipeline would be the value to set forSERVER_VERSION. - Open a pull request with this version change in the cilium repository.
Nightly Docker image¶
After each successful Nightly build, a cilium/nightly image is pushed to dockerhub.
To use latest nightly build, please use cilium/nightly:latest tag.
Nightly images are stored on dockerhub tagged with following format: YYYYMMDD-<job number>.
Job number is added to tag for the unlikely event of two consecutive nightly builds being built on the same date.
Developer’s Certificate of Origin¶
To improve tracking of who did what, we’ve introduced a “sign-off” procedure.
The sign-off is a simple line at the end of the explanation for the commit, which certifies that you wrote it or otherwise have the right to pass it on as open-source work. The rules are pretty simple: if you can certify the below:
Developer Certificate of Origin
Version 1.1
Copyright (C) 2004, 2006 The Linux Foundation and its contributors.
1 Letterman Drive
Suite D4700
San Francisco, CA, 94129
Everyone is permitted to copy and distribute verbatim copies of this
license document, but changing it is not allowed.
Developer's Certificate of Origin 1.1
By making a contribution to this project, I certify that:
(a) The contribution was created in whole or in part by me and I
have the right to submit it under the open source license
indicated in the file; or
(b) The contribution is based upon previous work that, to the best
of my knowledge, is covered under an appropriate open source
license and I have the right under that license to submit that
work with modifications, whether created in whole or in part
by me, under the same open source license (unless I am
permitted to submit under a different license), as indicated
in the file; or
(c) The contribution was provided directly to me by some other
person who certified (a), (b) or (c) and I have not modified
it.
(d) I understand and agree that this project and the contribution
are public and that a record of the contribution (including all
personal information I submit with it, including my sign-off) is
maintained indefinitely and may be redistributed consistent with
this project or the open source license(s) involved.
then you just add a line saying:
Signed-off-by: Random J Developer <random@developer.example.org>
Use your real name (sorry, no pseudonyms or anonymous contributions.)
Cilium Committer Grant/Revocation Policy¶
A Cilium committer is a participant in the project with the ability to commit code directly to the master repository. Commit access grants a broad ability to affect the progress of the project as presented by its most important artifact, the code and related resources that produce working binaries of Cilium. As such it represents a significant level of trust in an individual’s commitment to working with other committers and the community at large for the benefit of the project. It can not be granted lightly and, in the worst case, must be revocable if the trust placed in an individual was inappropriate.
This document suggests guidelines for granting and revoking commit access. It is intended to provide a framework for evaluation of such decisions without specifying deterministic rules that wouldn’t be sensitive to the nuance of specific situations. In the end the decision to grant or revoke committer privileges is a judgment call made by the existing set of committers.
Expectations for Developers with commit access¶
Pre-requisites¶
Be familiar with the Developer / Contributor Guide.
Review¶
Code (yours or others’) must be reviewed publicly (by you or others) before you push it to the repository. With one exception (see below), every change needs at least one review.
If one or more people know an area of code particularly well, code that affects that area should ordinarily get a review from one of them.
The riskier, more subtle, or more complicated the change, the more careful the review required. When a change needs careful review, use good judgment regarding the quality of reviews. If a change adds 1000 lines of new code, and a review posted 5 minutes later says just “Looks good,” then this is probably not a quality review.
(The size of a change is correlated with the amount of care needed in review, but it is not strictly tied to it. A search and replace across many files may not need much review, but one-line optimization changes can have widespread implications.)
Your own small changes to fix a recently broken build (“make”) or tests (“make check”), that you believe to be visible to a large number of developers, may be checked in without review. If you are not sure, ask for review.
Regularly review submitted code in areas where you have expertise. Consider reviewing other code as well.
Git conventions¶
If you apply a change (yours or another’s) then it is your responsibility to handle any resulting problems, especially broken builds and other regressions. If it is someone else’s change, then you can ask the original submitter to address it. Regardless, you need to ensure that the problem is fixed in a timely way. The definition of “timely” depends on the severity of the problem.
If a bug is present on master and other branches, fix it on master first, then backport the fix to other branches. Straightforward backports do not require additional review (beyond that for the fix on master).
Feature development should be done only on master. Occasionally it makes sense to add a feature to the most recent release branch, before the first actual release of that branch. These should be handled in the same way as bug fixes, that is, first implemented on master and then backported.
Keep the authorship of a commit clear by maintaining a correct list of “Signed-off-by:”s. If a confusing situation comes up, as it occasionally does, bring it up in the development forums. If you explain the use of “Signed-off-by:” to a new developer, explain not just how but why, since the intended meaning of “Signed-off-by:” is more important than the syntax.
Use Reported-by: and Tested-by: tags in commit messages to indicate the source of a bug report.
Keep the AUTHORS file up to date.
Granting Commit Access¶
Granting commit access should be considered when a candidate has demonstrated the following in their interaction with the project:
- Contribution of significant new features through the patch submission process where:
- Submissions are free of obvious critical defects
- Submissions do not typically require many iterations of improvement to be accepted
- Consistent participation in code review of other’s patches, including existing committers, with comments consistent with the overall project standards
- Assistance to those in the community who are less knowledgeable through active participation in project forums.
- Plans for sustained contribution to the project compatible with the project’s direction as viewed by current committers.
- Commitment to meet the expectations described in the “Expectations of Developer’s with commit access”
The process to grant commit access to a candidate is simple:
- An existing committer nominates the candidate by sending an email to all existing committers with information substantiating the contributions of the candidate in the areas described above.
- All existing committers discuss the pros and cons of granting commit access to the candidate in the email thread.
- When the discussion has converged or a reasonable time has elapsed without discussion developing (e.g. a few business days) the nominator calls for a final decision on the candidate with a followup email to the thread.
- Each committer may vote yes, no, or abstain by replying to the email thread. A failure to reply is an implicit abstention.
- After votes from all existing committers have been collected or a reasonable time has elapsed for them to be provided (e.g. a couple of business days) the votes are evaluated. To be granted commit access the candidate must receive yes votes from a majority of the existing committers and zero no votes. Since a no vote is effectively a veto of the candidate it should be accompanied by a reason for the vote.
- The nominator summarizes the result of the vote in an email to all existing committers.
- If the vote to grant commit access passed, the candidate is contacted with an invitation to become a committer to the project which asks them to agree to the committer expectations documented on the project web site.
- If the candidate agrees access is granted by setting up commit access to the repos.
Revoking Commit Access¶
There are two situations in which commit access might be revoked.
The straightforward situation is a committer who is no longer active in the project and has no plans to become active in the near future. The process in this case is:
- Any time after a committer has been inactive for more than 6 months any other committer to the project may identify that committer as a candidate for revocation of commit access due to inactivity.
- The plans of revocation should be sent in a private email to the candidate.
- If the candidate for removal states plans to continue participating no action is taken and this process terminates.
- If the candidate replies they no longer require commit access then commit access is removed and a notification is sent to the candidate and all existing committers.
- If the candidate can not be reached within 1 week of the first attempting to contact this process continues.
- A message proposing removal of commit access is sent to the candidate and all other committers.
- If the candidate for removal states plans to continue participating no action is taken.
- If the candidate replies they no longer require commit access then their access is removed.
- If the candidate can not be reached within 2 months of the second attempting to contact them, access is removed.
- In any case, where access is removed, this fact is published through an email to all existing committers (including the candidate for removal).
The more difficult situation is a committer who is behaving in a manner that is viewed as detrimental to the future of the project by other committers. This is a delicate situation with the potential for the creation of division within the greater community and should be handled with care. The process in this case is:
- Discuss the behavior of concern with the individual privately and explain why you believe it is detrimental to the project. Stick to the facts and keep the email professional. Avoid personal attacks and the temptation to hypothesize about unknowable information such as the other’s motivations. Make it clear that you would prefer not to discuss the behavior more widely but will have to raise it with other contributors if it does not change. Ideally the behavior is eliminated and no further action is required. If not,
- Start an email thread with all committers, including the source of the behavior, describing the behavior and the reason it is detrimental to the project. The message should have the same tone as the private discussion and should generally repeat the same points covered in that discussion. The person whose behavior is being questioned should not be surprised by anything presented in this discussion. Ideally the wider discussion provides more perspective to all participants and the issue is resolved. If not,
- Start an email thread with all committers except the source of the detrimental behavior requesting a vote on revocation of commit rights. Cite the discussion among all committers and describe all the reasons why it was not resolved satisfactorily. This email should be carefully written with the knowledge that the reasoning it contains may be published to the larger community to justify the decision.
- Each committer may vote yes, no, or abstain by replying to the email thread. A failure to reply is an implicit abstention.
- After all votes have been collected or a reasonable time has elapsed for them to be provided (e.g. a couple of business days) the votes are evaluated. For the request to revoke commit access for the candidate to pass it must receive yes votes from two thirds of the existing committers.
- anyone that votes no must provide their reasoning, and
- if the proposal passes then counter-arguments for the reasoning in no votes should also be documented along with the initial reasons the revocation was proposed. Ideally there should be no new counter-arguments supplied in a no vote as all concerns should have surfaced in the discussion before the vote.
- The original person to propose revocation summarizes the result of the vote in an email to all existing committers excepting the candidate for removal.
- If the vote to revoke commit access passes, access is removed and the candidate for revocation is informed of that fact and the reasons for it as documented in the email requesting the revocation vote.
- Ideally the revoked committer peacefully leaves the community and no further action is required. However, there is a distinct possibility that he/she will try to generate support for his/her point of view within the larger community. In this case the reasoning for removing commit access as described in the request for a vote will be published to the community.
Changing the Policy¶
The process for changing the policy is:
- Propose the changes to the policy in an email to all current committers and request discussion.
- After an appropriate period of discussion (a few days) update the proposal based on feedback if required and resend it to all current committers with a request for a formal vote.
- After all votes have been collected or a reasonable time has elapsed for them to be provided (e.g. a couple of business days) the votes are evaluated. For the request to modify the policy to pass it must receive yes votes from two thirds of the existing committers.
Template Emails¶
Nomination to Grant Commit Access¶
I would like to nominate *[candidate]* for commit access. I believe
*[he/she]* has met the conditions for commit access described in the
committer grant policy on the project web site in the following ways:
*[list of requirements & evidence]*
Please reply to all in this message thread with your comments and
questions. If that discussion concludes favorably I will request a formal
vote on the nomination in a few days.
Vote to Grant Commit Access¶
I nominated *[candidate]* for commit access on *[date]*. Having allowed
sufficient time for discussion it's now time to formally vote on the
proposal.
Please reply to all in this thread with your vote of: YES, NO, or ABSTAIN.
A failure to reply will be counted as an abstention. If you vote NO, by our
policy you must include the reasons for that vote in your reply. The
deadline for votes is *[date and time]*.
If a majority of committers vote YES and there are zero NO votes commit
access will be granted.
Vote Results for Grant of Commit Access¶
The voting period for granting to commit access to *[candidate]* initiated
at *[date and time]* is now closed with the following results:
YES: *[count of yes votes]* (*[% of voters]*)
NO: *[count of no votes]* (*[% of voters]*)
ABSTAIN: *[count of abstentions]* (*[% of voters]*)
Based on these results commit access *[is/is NOT]* granted.
Invitation to Accepted Committer¶
Due to your sustained contributions to the Cilium project we
would like to provide you with commit access to the project repository.
Developers with commit access must agree to fulfill specific
responsibilities described in the source repository:
/Documentation/commit-access.rst
Please let us know if you would like to accept commit access and if so that
you agree to fulfill these responsibilities. Once we receive your response
we'll set up access. We're looking forward continuing to work together to
advance the Cilium project.
Proposal to Remove Commit Access for Inactivity¶
Committer *[candidate]* has been inactive for *[duration]*. I have
attempted to privately contacted *[him/her]* and *[he/she]* could not be
reached.
Based on this I would like to formally propose removal of commit access.
If a response to this message documenting the reasons to retain commit
access is not received by *[date]* access will be removed.
Notification of Commit Removal for Inactivity¶
Committer *[candidate]* has been inactive for *[duration]*. *[He/she]*
*[stated no commit access is required/failed to respond]* to the formal
proposal to remove access on *[date]*. Commit access has now been removed.
Proposal to Revoke Commit Access for Detrimental Behavior¶
I regret that I feel compelled to propose revocation of commit access for
*[candidate]*. I have privately discussed with *[him/her]* the following
reasons I believe *[his/her]* actions are detrimental to the project and we
have failed to come to a mutual understanding:
*[List of reasons and supporting evidence]*
Please reply to all in this thread with your thoughts on this proposal. I
plan to formally propose a vote on the proposal on or after *[date and
time]*.
It is important to get all discussion points both for and against the
proposal on the table during the discussion period prior to the vote.
Please make it a high priority to respond to this proposal with your
thoughts.
Vote to Revoke Commit Access¶
I nominated *[candidate]* for revocation of commit access on *[date]*.
Having allowed sufficient time for discussion it's now time to formally
vote on the proposal.
Please reply to all in this thread with your vote of: YES, NO, or ABSTAIN.
A failure to reply will be counted as an abstention. If you vote NO, by our
policy you must include the reasons for that vote in your reply. The
deadline for votes is *[date and time]*.
If 2/3rds of committers vote YES commit access will be revoked.
The following reasons for revocation have been given in the original
proposal or during discussion:
*[list of reasons to remove access]*
The following reasons for retaining access were discussed:
*[list of reasons to retain access]*
The counter-argument for each reason for retaining access is:
*[list of counter-arguments for retaining access]*
Vote Results for Revocation of Commit Access¶
The voting period for revoking the commit access of *[candidate]* initiated
at *[date and time]* is now closed with the following results:
- YES: *[count of yes votes]* (*[% of voters]*)
- NO: *[count of no votes]* (*[% of voters]*)
- ABSTAIN: *[count of abstentions]* (*[% of voters]*)
Based on these results commit access *[is/is NOT]* revoked. The following
reasons for retaining commit access were proposed in NO votes:
*[list of reasons]*
The counter-arguments for each of these reasons are:
*[list of counter-arguments]*
Notification of Commit Revocation for Detrimental Behavior¶
After private discussion with you and careful consideration of the
situation, the other committers to the Cilium project have
concluded that it is in the best interest of the project that your commit
access to the project repositories be revoked and this has now occurred.
The reasons for this decision are:
*[list of reasons for removing access]*
While your goals and those of the project no longer appear to be aligned we
greatly appreciate all the work you have done for the project and wish you
continued success in your future work.
BPF and XDP Reference Guide¶
Note
This documentation section is targeted at developers and users who want to understand BPF and XDP in great technical depth. While reading this reference guide may help broaden your understanding of Cilium, it is not a requirement to use Cilium. Please refer to the Getting Started Guides and Architecture for a higher level introduction.
BPF is a highly flexible and efficient virtual machine-like construct in the Linux kernel allowing to execute bytecode at various hook points in a safe manner. It is used in a number of Linux kernel subsystems, most prominently networking, tracing and security (e.g. sandboxing).
Although BPF exists since 1992, this document covers the extended Berkeley Packet Filter (eBPF) version which has first appeared in Kernel 3.18 and renders the original version which is being referred to as “classic” BPF (cBPF) these days mostly obsolete. cBPF is known to many as being the packet filter language used by tcpdump. Nowadays, the Linux kernel runs eBPF only and loaded cBPF bytecode is transparently translated into an eBPF representation in the kernel before program execution. This documentation will generally refer to the term BPF unless explicit differences between eBPF and cBPF are being pointed out.
Even though the name Berkeley Packet Filter hints at a packet filtering specific purpose, the instruction set is generic and flexible enough these days that there are many use cases for BPF apart from networking. See Further Reading for a list of projects which use BPF.
Cilium uses BPF heavily in its data path, see Architecture for further information. The goal of this chapter is to provide a BPF reference guide in order to gain understanding of BPF, its networking specific use including loading BPF programs with tc (traffic control) and XDP (eXpress Data Path), and to aid with developing Cilium’s BPF templates.
BPF Architecture¶
BPF does not define itself by only providing its instruction set, but also by offering further infrastructure around it such as maps which act as efficient key / value stores, helper functions to interact with and leverage kernel functionality, tail calls for calling into other BPF programs, security hardening primitives, a pseudo file system for pinning objects (maps, programs), and infrastructure for allowing BPF to be offloaded, for example, to a network card.
LLVM provides a BPF back end, so that tools like clang can be used to compile C into a BPF object file, which can then be loaded into the kernel. BPF is deeply tied to the Linux kernel and allows for full programmability without sacrificing native kernel performance.
Last but not least, also the kernel subsystems making use of BPF are part of BPF’s infrastructure. The two main subsystems discussed throughout this document are tc and XDP where BPF programs can be attached to. XDP BPF programs are attached at the earliest networking driver stage and trigger a run of the BPF program upon packet reception. By definition, this achieves the best possible packet processing performance since packets cannot get processed at an even earlier point in software. However, since this processing occurs so early in the networking stack, the stack has not yet extracted metadata out of the packet. On the other hand, tc BPF programs are executed later in the kernel stack, so they have access to more metadata and core kernel functionality. Apart from tc and XDP programs, there are various other kernel subsystems as well which use BPF such as tracing (kprobes, uprobes, tracepoints, etc).
The following subsections provide further details on individual aspects of the BPF architecture.
Instruction Set¶
BPF is a general purpose RISC instruction set and was originally designed for the purpose of writing programs in a subset of C which can be compiled into BPF instructions through a compiler back end (e.g. LLVM), so that the kernel can later on map them through an in-kernel JIT compiler into native opcodes for optimal execution performance inside the kernel.
The advantages for pushing these instructions into the kernel include:
- Making the kernel programmable without having to cross kernel / user space boundaries. For example, BPF programs related to networking, as in the case of Cilium, can implement flexible container policies, load balancing and other means without having to move packets to user space and back into the kernel. State between BPF programs and kernel / user space can still be shared through maps whenever needed.
- Given the flexibility of a programmable data path, programs can be heavily optimized for performance also by compiling out features that are not required for the use cases the program solves. For example, if a container does not require IPv4, then the BPF program can be built to only deal with IPv6 in order to save resources in the fast-path.
- In case of networking (e.g. tc and XDP), BPF programs can be updated atomically without having to restart the kernel, system services or containers, and without traffic interruptions. Furthermore, any program state can also be maintained throughout updates via BPF maps.
- BPF provides a stable ABI towards user space, and does not require any third party kernel modules. BPF is a core part of the Linux kernel that is shipped everywhere, and guarantees that existing BPF programs keep running with newer kernel versions. This guarantee is the same guarantee that the kernel provides for system calls with regard to user space applications. Moreover, BPF programs are portable across different architectures.
- BPF programs work in concert with the kernel, they make use of existing kernel infrastructure (e.g. drivers, netdevices, tunnels, protocol stack, sockets) and tooling (e.g. iproute2) as well as the safety guarantees which the kernel provides. Unlike kernel modules, BPF programs are verified through an in-kernel verifier in order to ensure that they cannot crash the kernel, always terminate, etc. XDP programs, for example, reuse the existing in-kernel drivers and operate on the provided DMA buffers containing the packet frames without exposing them or an entire driver to user space as in other models. Moreover, XDP programs reuse the existing stack instead of bypassing it. BPF can be considered a generic “glue code” to kernel facilities for crafting programs to solve specific use cases.
The execution of a BPF program inside the kernel is always event driven! For example, a networking device which has a BPF program attached on its ingress path will trigger the execution of the program once a packet is received, a kernel address which has a kprobes with a BPF program attached will trap once the code at that address gets executed, then invoke the kprobes callback function for instrumentation which subsequently triggers the execution of the BPF program attached to it.
BPF consists of eleven 64 bit registers with 32 bit subregisters, a program counter
and a 512 byte large BPF stack space. Registers are named r0 - r10. The
operating mode is 64 bit by default, the 32 bit subregisters can only be accessed
through special ALU (arithmetic logic unit) operations. The 32 bit lower subregisters
zero-extend into 64 bit when they are being written to.
Register r10 is the only register which is read-only and contains the frame pointer
address in order to access the BPF stack space. The remaining r0 - r9
registers are general purpose and of read/write nature.
A BPF program can call into a predefined helper function, which is defined by the core kernel (never by modules). The BPF calling convention is defined as follows:
r0contains the return value of a helper function call.r1-r5hold arguments from the BPF program to the kernel helper function.r6-r9are callee saved registers that will be preserved on helper function call.
The BPF calling convention is generic enough to map directly to x86_64, arm64
and other ABIs, thus all BPF registers map one to one to HW CPU registers, so that a
JIT only needs to issue a call instruction, but no additional extra moves for placing
function arguments. This calling convention was modeled to cover common call
situations without having a performance penalty. Calls with 6 or more arguments
are currently not supported. The helper functions in the kernel which are dedicated
to BPF (BPF_CALL_0() to BPF_CALL_5() functions) are specifically designed
with this convention in mind.
Register r0 is also the register containing the exit value for the BPF program.
The semantics of the exit value are defined by the type of program. Furthermore, when
handing execution back to the kernel, the exit value is passed as a 32 bit value.
Registers r1 - r5 are scratch registers, meaning the BPF program needs to
either spill them to the BPF stack or move them to callee saved registers if these
arguments are to be reused across multiple helper function calls. Spilling means
that the variable in the register is moved to the BPF stack. The reverse operation
of moving the variable from the BPF stack to the register is called filling. The
reason for spilling/filling is due to the limited number of registers.
Upon entering execution of a BPF program, register r1 initially contains the
context for the program. The context is the input argument for the program (similar
to argc/argv pair for a typical C program). BPF is restricted to work on a single
context. The context is defined by the program type, for example, a networking
program can have a kernel representation of the network packet (skb) as the
input argument.
The general operation of BPF is 64 bit to follow the natural model of 64 bit architectures in order to perform pointer arithmetics, pass pointers but also pass 64 bit values into helper functions, and to allow for 64 bit atomic operations.
The maximum instruction limit per program is restricted to 4096 BPF instructions, which, by design, means that any program will terminate quickly. Although the instruction set contains forward as well as backward jumps, the in-kernel BPF verifier will forbid loops so that termination is always guaranteed. Since BPF programs run inside the kernel, the verifier’s job is to make sure that these are safe to run, not affecting the system’s stability. This means that from an instruction set point of view, loops can be implemented, but the verifier will restrict that. However, there is also a concept of tail calls that allows for one BPF program to jump into another one. This, too, comes with an upper nesting limit of 32 calls, and is usually used to decouple parts of the program logic, for example, into stages.
The instruction format is modeled as two operand instructions, which helps mapping
BPF instructions to native instructions during JIT phase. The instruction set is
of fixed size, meaning every instruction has 64 bit encoding. Currently, 87 instructions
have been implemented and the encoding also allows to extend the set with further
instructions when needed. The instruction encoding of a single 64 bit instruction on a
big-endian machine is defined as a bit sequence from most significant bit (MSB) to least
significant bit (LSB) of op:8, dst_reg:4, src_reg:4, off:16, imm:32.
off and imm is of signed type. The encodings are part of the kernel headers and
defined in linux/bpf.h header, which also includes linux/bpf_common.h.
op defines the actual operation to be performed. Most of the encoding for op
has been reused from cBPF. The operation can be based on register or immediate
operands. The encoding of op itself provides information on which mode to use
(BPF_X for denoting register-based operations, and BPF_K for immediate-based
operations respectively). In the latter case, the destination operand is always
a register. Both dst_reg and src_reg provide additional information about
the register operands to be used (e.g. r0 - r9) for the operation. off
is used in some instructions to provide a relative offset, for example, for addressing
the stack or other buffers available to BPF (e.g. map values, packet data, etc),
or jump targets in jump instructions. imm contains a constant / immediate value.
The available op instructions can be categorized into various instruction
classes. These classes are also encoded inside the op field. The op field
is divided into (from MSB to LSB) code:4, source:1 and class:3. class
is the more generic instruction class, code denotes a specific operational
code inside that class, and source tells whether the source operand is a register
or an immediate value. Possible instruction classes include:
BPF_LD,BPF_LDX: Both classes are for load operations.BPF_LDis used for loading a double word as a special instruction spanning two instructions due to theimm:32split, and for byte / half-word / word loads of packet data. The latter was carried over from cBPF mainly in order to keep cBPF to BPF translations efficient, since they have optimized JIT code. For native BPF these packet load instructions are less relevant nowadays.BPF_LDXclass holds instructions for byte / half-word / word / double-word loads out of memory. Memory in this context is generic and could be stack memory, map value data, packet data, etc.BPF_ST,BPF_STX: Both classes are for store operations. Similar toBPF_LDXtheBPF_STXis the store counterpart and is used to store the data from a register into memory, which, again, can be stack memory, map value, packet data, etc.BPF_STXalso holds special instructions for performing word and double-word based atomic add operations, which can be used for counters, for example. TheBPF_STclass is similar toBPF_STXby providing instructions for storing data into memory only that the source operand is an immediate value.BPF_ALU,BPF_ALU64: Both classes contain ALU operations. Generally,BPF_ALUoperations are in 32 bit mode andBPF_ALU64in 64 bit mode. Both ALU classes have basic operations with source operand which is register-based and an immediate-based counterpart. Supported by both are add (+), sub (-), and (&), or (|), left shift (<<), right shift (>>), xor (^), mul (*), div (/), mod (%), neg (~) operations. Also mov (<X> := <Y>) was added as a special ALU operation for both classes in both operand modes.BPF_ALU64also contains a signed right shift.BPF_ALUadditionally contains endianness conversion instructions for half-word / word / double-word on a given source register.BPF_JMP: This class is dedicated to jump operations. Jumps can be unconditional and conditional. Unconditional jumps simply move the program counter forward, so that the next instruction to be executed relative to the current instruction isoff + 1, whereoffis the constant offset encoded in the instruction. Sinceoffis signed, the jump can also be performed backwards as long as it does not create a loop and is within program bounds. Conditional jumps operate on both, register-based and immediate-based source operands. If the condition in the jump operations results intrue, then a relative jump tooff + 1is performed, otherwise the next instruction (0 + 1) is performed. This fall-through jump logic differs compared to cBPF and allows for better branch prediction as it fits the CPU branch predictor logic more naturally. Available conditions are jeq (==), jne (!=), jgt (>), jge (>=), jsgt (signed>), jsge (signed>=), jlt (<), jle (<=), jslt (signed<), jsle (signed<=) and jset (jump ifDST & SRC). Apart from that, there are three special jump operations within this class: the exit instruction which will leave the BPF program and return the current value inr0as a return code, the call instruction, which will issue a function call into one of the available BPF helper functions, and a hidden tail call instruction, which will jump into a different BPF program.
The Linux kernel is shipped with a BPF interpreter which executes programs assembled in BPF instructions. Even cBPF programs are translated into eBPF programs transparently in the kernel, except for architectures that still ship with a cBPF JIT and have not yet migrated to an eBPF JIT.
Currently x86_64, arm64, ppc64, s390x, mips64, sparc64 and
arm architectures come with an in-kernel eBPF JIT compiler.
All BPF handling such as loading of programs into the kernel or creation of BPF maps
is managed through a central bpf() system call. It is also used for managing map
entries (lookup / update / delete), and making programs as well as maps persistent
in the BPF file system through pinning.
Helper Functions¶
Helper functions are a concept which enables BPF programs to consult a core kernel defined set of function calls in order to retrieve / push data from / to the kernel. Available helper functions may differ for each BPF program type, for example, BPF programs attached to sockets are only allowed to call into a subset of helpers compared to BPF programs attached to the tc layer. Encapsulation and decapsulation helpers for lightweight tunneling constitute an example of functions which are only available to lower tc layers, whereas event output helpers for pushing notifications to user space are available to tc and XDP programs.
Each helper function is implemented with a commonly shared function signature similar to system calls. The signature is defined as:
u64 fn(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
The calling convention as described in the previous section applies to all BPF helper functions.
The kernel abstracts helper functions into macros BPF_CALL_0() to BPF_CALL_5()
which are similar to those of system calls. The following example is an extract
from a helper function which updates map elements by calling into the
corresponding map implementation callbacks:
BPF_CALL_4(bpf_map_update_elem, struct bpf_map *, map, void *, key,
void *, value, u64, flags)
{
WARN_ON_ONCE(!rcu_read_lock_held());
return map->ops->map_update_elem(map, key, value, flags);
}
const struct bpf_func_proto bpf_map_update_elem_proto = {
.func = bpf_map_update_elem,
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_CONST_MAP_PTR,
.arg2_type = ARG_PTR_TO_MAP_KEY,
.arg3_type = ARG_PTR_TO_MAP_VALUE,
.arg4_type = ARG_ANYTHING,
};
There are various advantages of this approach: while cBPF overloaded its load instructions in order to fetch data at an impossible packet offset to invoke auxiliary helper functions, each cBPF JIT needed to implement support for such a cBPF extension. In case of eBPF, each newly added helper function will be JIT compiled in a transparent and efficient way, meaning that the JIT compiler only needs to emit a call instruction since the register mapping is made in such a way that BPF register assignments already match the underlying architecture’s calling convention. This allows for easily extending the core kernel with new helper functionality. All BPF helper functions are part of the core kernel and cannot be extended or added through kernel modules.
The aforementioned function signature also allows the verifier to perform type
checks. The above struct bpf_func_proto is used to hand all the necessary
information which need to be known about the helper to the verifier, so that
the verifier can make sure that the expected types from the helper match the
current contents of the BPF program’s analyzed registers.
Argument types can range from passing in any kind of value up to restricted contents such as a pointer / size pair for the BPF stack buffer, which the helper should read from or write to. In the latter case, the verifier can also perform additional checks, for example, whether the buffer was previously initialized.
The list of available BPF helper functions is rather long and constantly growing,
for example, at the time of this writing, tc BPF programs can choose from 38
different BPF helpers. The kernel’s struct bpf_verifier_ops contains a
get_func_proto callback function that provides the mapping of a specific
enum bpf_func_id to one of the available helpers for a given BPF program
type.
Maps¶
Maps are efficient key / value stores that reside in kernel space. They can be accessed from a BPF program in order to keep state among multiple BPF program invocations. They can also be accessed through file descriptors from user space and can be arbitrarily shared with other BPF programs or user space applications.
BPF programs which share maps with each other are not required to be of the same program type, for example, tracing programs can share maps with networking programs. A single BPF program can currently access up to 64 different maps directly.
Map implementations are provided by the core kernel. There are generic maps with per-CPU and non-per-CPU flavor that can read / write arbitrary data, but there are also a few non-generic maps that are used along with helper functions.
Generic maps currently available are BPF_MAP_TYPE_HASH, BPF_MAP_TYPE_ARRAY,
BPF_MAP_TYPE_PERCPU_HASH, BPF_MAP_TYPE_PERCPU_ARRAY, BPF_MAP_TYPE_LRU_HASH,
BPF_MAP_TYPE_LRU_PERCPU_HASH and BPF_MAP_TYPE_LPM_TRIE. They all use the
same common set of BPF helper functions in order to perform lookup, update or
delete operations while implementing a different backend with differing semantics
and performance characteristics.
Non-generic maps that are currently in the kernel are BPF_MAP_TYPE_PROG_ARRAY,
BPF_MAP_TYPE_PERF_EVENT_ARRAY, BPF_MAP_TYPE_CGROUP_ARRAY,
BPF_MAP_TYPE_STACK_TRACE, BPF_MAP_TYPE_ARRAY_OF_MAPS,
BPF_MAP_TYPE_HASH_OF_MAPS. For example, BPF_MAP_TYPE_PROG_ARRAY is an
array map which holds other BPF programs, BPF_MAP_TYPE_ARRAY_OF_MAPS and
BPF_MAP_TYPE_HASH_OF_MAPS both hold pointers to other maps such that entire
BPF maps can be atomically replaced at runtime. These types of maps tackle a
specific issue which was unsuitable to be implemented solely through a BPF helper
function since additional (non-data) state is required to be held across BPF
program invocations.
Object Pinning¶
BPF maps and programs act as a kernel resource and can only be accessed through file descriptors, backed by anonymous inodes in the kernel. Advantages, but also a number of disadvantages come along with them:
User space applications can make use of most file descriptor related APIs, file descriptor passing for Unix domain sockets work transparently, etc, but at the same time, file descriptors are limited to a processes’ lifetime, which makes options like map sharing rather cumbersome to carry out.
Thus, it brings a number of complications for certain use cases such as iproute2, where tc or XDP sets up and loads the program into the kernel and terminates itself eventually. With that, also access to maps is unavailable from user space side, where it could otherwise be useful, for example, when maps are shared between ingress and egress locations of the data path. Also, third party applications may wish to monitor or update map contents during BPF program runtime.
To overcome this limitation, a minimal kernel space BPF file system has been
implemented, where BPF map and programs can be pinned to, a process called
object pinning. The BPF system call has therefore been extended with two new
commands which can pin (BPF_OBJ_PIN) or retrieve (BPF_OBJ_GET) a
previously pinned object.
For instance, tools such as tc make use of this infrastructure for sharing maps on ingress and egress. The BPF related file system is not a singleton, it does support multiple mount instances, hard and soft links, etc.
Tail Calls¶
Another concept that can be used with BPF is called tail calls. Tail calls can be seen as a mechanism that allows one BPF program to call another, without returning back to the old program. Such a call has minimal overhead as unlike function calls, it is implemented as a long jump, reusing the same stack frame.
Such programs are verified independently of each other, thus for transferring
state, either per-CPU maps as scratch buffers or in case of tc programs, skb
fields such as the cb[] area must be used.
Only programs of the same type can be tail called, and they also need to match in terms of JIT compilation, thus either JIT compiled or only interpreted programs can be invoked, but not mixed together.
There are two components involved for carrying out tail calls: the first part
needs to setup a specialized map called program array (BPF_MAP_TYPE_PROG_ARRAY)
that can be populated by user space with key / values, where values are the
file descriptors of the tail called BPF programs, the second part is a
bpf_tail_call() helper where the context, a reference to the program array
and the lookup key is passed to. Then the kernel inlines this helper call
directly into a specialized BPF instruction. Such a program array is currently
write-only from user space side.
The kernel looks up the related BPF program from the passed file descriptor
and atomically replaces program pointers at the given map slot. When no map
entry has been found at the provided key, the kernel will just “fall through”
and continue execution of the old program with the instructions following
after the bpf_tail_call(). Tail calls are a powerful utility, for example,
parsing network headers could be structured through tail calls. During runtime,
functionality can be added or replaced atomically, and thus altering the BPF
program’s execution behavior.
BPF to BPF Calls¶
Aside from BPF helper calls and BPF tail calls, a more recent feature that has
been added to the BPF core infrastructure is BPF to BPF calls. Before this
feature was introduced into the kernel, a typical BPF C program had to declare
any reusable code that, for example, resides in headers as always_inline
such that when LLVM compiles and generates the BPF object file all these
functions were inlined and therefore duplicated many times in the resulting
object file, artificially inflating its code size:
#include <linux/bpf.h> #ifndef __section # define __section(NAME) \ __attribute__((section(NAME), used)) #endif #ifndef __inline # define __inline \ inline __attribute__((always_inline)) #endif static __inline int foo(void) { return XDP_DROP; } __section("prog") int xdp_drop(struct xdp_md *ctx) { return foo(); } char __license[] __section("license") = "GPL";
The main reason why this was necessary was due to lack of function call support
in the BPF program loader as well as verifier, interpreter and JITs. Starting
with Linux kernel 4.16 and LLVM 6.0 this restriction got lifted and BPF programs
no longer need to use always_inline everywhere. Thus, the prior shown BPF
example code can then be rewritten more naturally as:
#include <linux/bpf.h> #ifndef __section # define __section(NAME) \ __attribute__((section(NAME), used)) #endif static int foo(void) { return XDP_DROP; } __section("prog") int xdp_drop(struct xdp_md *ctx) { return foo(); } char __license[] __section("license") = "GPL";
Mainstream BPF JIT compilers like x86_64 and arm64 support BPF to BPF
calls today with others following in near future. BPF to BPF call is an
important performance optimization since it heavily reduces the generated BPF
code size and therefore becomes friendlier to a CPU’s instruction cache.
The calling convention known from BPF helper function applies to BPF to BPF
calls just as well, meaning r1 up to r5 are for passing arguments to
the callee and the result is returned in r0. r1 to r5 are scratch
registers whereas r6 to r9 preserved across calls the usual way. The
maximum number of nesting calls respectively allowed call frames is 8.
A caller can pass pointers (e.g. to the caller’s stack frame) down to the
callee, but never vice versa.
BPF to BPF calls are currently incompatible with the use of BPF tail calls, since the latter requires to reuse the current stack setup as-is, whereas the former adds additional stack frames and thus changes the expected layout for tail calls.
BPF JIT compilers emit separate images for each function body and later fix up the function call addresses in the image in a final JIT pass. This has proven to require minimal changes to the JITs in that they can treat BPF to BPF calls as conventional BPF helper calls.
JIT¶
The 64 bit x86_64, arm64, ppc64, s390x, mips64, sparc64
and 32 bit arm, x86_32 architectures are all shipped with an in-kernel
eBPF JIT compiler, also all of them are feature equivalent and can be enabled
through:
# echo 1 > /proc/sys/net/core/bpf_jit_enable
The 32 bit mips, ppc and sparc architectures currently have a cBPF
JIT compiler. The mentioned architectures still having a cBPF JIT as well as all
remaining architectures supported by the Linux kernel which do not have a BPF JIT
compiler at all need to run eBPF programs through the in-kernel interpreter.
In the kernel’s source tree, eBPF JIT support can be easily determined through
issuing a grep for HAVE_EBPF_JIT:
# git grep HAVE_EBPF_JIT arch/
arch/arm/Kconfig: select HAVE_EBPF_JIT if !CPU_ENDIAN_BE32
arch/arm64/Kconfig: select HAVE_EBPF_JIT
arch/powerpc/Kconfig: select HAVE_EBPF_JIT if PPC64
arch/mips/Kconfig: select HAVE_EBPF_JIT if (64BIT && !CPU_MICROMIPS)
arch/s390/Kconfig: select HAVE_EBPF_JIT if PACK_STACK && HAVE_MARCH_Z196_FEATURES
arch/sparc/Kconfig: select HAVE_EBPF_JIT if SPARC64
arch/x86/Kconfig: select HAVE_EBPF_JIT if X86_64
JIT compilers speed up execution of the BPF program significantly since they
reduce the per instruction cost compared to the interpreter. Often instructions
can be mapped 1:1 with native instructions of the underlying architecture. This
also reduces the resulting executable image size and is therefore more
instruction cache friendly to the CPU. In particular in case of CISC instruction
sets such as x86, the JITs are optimized for emitting the shortest possible
opcodes for a given instruction to shrink the total necessary size for the
program translation.
Hardening¶
BPF locks the entire BPF interpreter image (struct bpf_prog) as well
as the JIT compiled image (struct bpf_binary_header) in the kernel as
read-only during the program’s lifetime in order to prevent the code from
potential corruptions. Any corruption happening at that point, for example,
due to some kernel bugs will result in a general protection fault and thus
crash the kernel instead of allowing the corruption to happen silently.
Architectures that support setting the image memory as read-only can be determined through:
$ git grep ARCH_HAS_SET_MEMORY | grep select
arch/arm/Kconfig: select ARCH_HAS_SET_MEMORY
arch/arm64/Kconfig: select ARCH_HAS_SET_MEMORY
arch/s390/Kconfig: select ARCH_HAS_SET_MEMORY
arch/x86/Kconfig: select ARCH_HAS_SET_MEMORY
The option CONFIG_ARCH_HAS_SET_MEMORY is not configurable, thanks to
which this protection is always built-in. Other architectures might follow
in the future.
In case of the x86_64 JIT compiler, the JITing of the indirect jump from
the use of tail calls is realized through a retpoline in case CONFIG_RETPOLINE
has been set which is the default at the time of writing in most modern Linux
distributions.
In case of /proc/sys/net/core/bpf_jit_harden set to 1 additional
hardening steps for the JIT compilation take effect for unprivileged users.
This effectively trades off their performance slightly by decreasing a
(potential) attack surface in case of untrusted users operating on the
system. The decrease in program execution still results in better performance
compared to switching to interpreter entirely.
Currently, enabling hardening will blind all user provided 32 bit and 64 bit constants from the BPF program when it gets JIT compiled in order to prevent JIT spraying attacks which inject native opcodes as immediate values. This is problematic as these immediate values reside in executable kernel memory, therefore a jump that could be triggered from some kernel bug would jump to the start of the immediate value and then execute these as native instructions.
JIT constant blinding prevents this due to randomizing the actual instruction,
which means the operation is transformed from an immediate based source operand
to a register based one through rewriting the instruction by splitting the
actual load of the value into two steps: 1) load of a blinded immediate
value rnd ^ imm into a register, 2) xoring that register with rnd
such that the original imm immediate then resides in the register and
can be used for the actual operation. The example was provided for a load
operation, but really all generic operations are blinded.
Example of JITing a program with hardening disabled:
# echo 0 > /proc/sys/net/core/bpf_jit_harden
ffffffffa034f5e9 + <x>:
[...]
39: mov $0xa8909090,%eax
3e: mov $0xa8909090,%eax
43: mov $0xa8ff3148,%eax
48: mov $0xa89081b4,%eax
4d: mov $0xa8900bb0,%eax
52: mov $0xa810e0c1,%eax
57: mov $0xa8908eb4,%eax
5c: mov $0xa89020b0,%eax
[...]
The same program gets constant blinded when loaded through BPF as an unprivileged user in the case hardening is enabled:
# echo 1 > /proc/sys/net/core/bpf_jit_harden
ffffffffa034f1e5 + <x>:
[...]
39: mov $0xe1192563,%r10d
3f: xor $0x4989b5f3,%r10d
46: mov %r10d,%eax
49: mov $0xb8296d93,%r10d
4f: xor $0x10b9fd03,%r10d
56: mov %r10d,%eax
59: mov $0x8c381146,%r10d
5f: xor $0x24c7200e,%r10d
66: mov %r10d,%eax
69: mov $0xeb2a830e,%r10d
6f: xor $0x43ba02ba,%r10d
76: mov %r10d,%eax
79: mov $0xd9730af,%r10d
7f: xor $0xa5073b1f,%r10d
86: mov %r10d,%eax
89: mov $0x9a45662b,%r10d
8f: xor $0x325586ea,%r10d
96: mov %r10d,%eax
[...]
Both programs are semantically the same, only that none of the original immediate values are visible anymore in the disassembly of the second program.
At the same time, hardening also disables any JIT kallsyms exposure
for privileged users, preventing that JIT image addresses are not
exposed to /proc/kallsyms anymore.
Moreover, the Linux kernel provides the option CONFIG_BPF_JIT_ALWAYS_ON
which removes the entire BPF interpreter from the kernel and permanently
enables the JIT compiler. This has been developed as part of a mitigation
in the context of Spectre v2 such that when used in a VM-based setting,
the guest kernel is not going to reuse the host kernel’s BPF interpreter
when mounting an attack anymore. For container-based environments, the
CONFIG_BPF_JIT_ALWAYS_ON configuration option is optional, but in
case JITs are enabled there anyway, the interpreter may as well be compiled
out to reduce the kernel’s complexity. Thus, it is also generally
recommended for widely used JITs in case of main stream architectures
such as x86_64 and arm64.
Last but not least, the kernel offers an option to disable the use of
the bpf(2) system call for unprivileged users through the
/proc/sys/kernel/unprivileged_bpf_disabled sysctl knob. This is
on purpose a one-time kill switch, meaning once set to 1, there is
no option to reset it back to 0 until a new kernel reboot. When
set only CAP_SYS_ADMIN privileged processes out of the initial
namespace are allowed to use the bpf(2) system call from that
point onwards. Upon start, Cilium sets this knob to 1 as well.
# echo 1 > /proc/sys/kernel/unprivileged_bpf_disabled
Offloads¶
Networking programs in BPF, in particular for tc and XDP do have an offload-interface to hardware in the kernel in order to execute BPF code directly on the NIC.
Currently, the nfp driver from Netronome has support for offloading
BPF through a JIT compiler which translates BPF instructions to an
instruction set implemented against the NIC. This includes offloading
of BPF maps to the NIC as well, thus the offloaded BPF program can
perform map lookups, updates and deletions.
Toolchain¶
Current user space tooling, introspection facilities and kernel control knobs around BPF are discussed in this section. Note, the tooling and infrastructure around BPF is still rapidly evolving and thus may not provide a complete picture of all available tools.
Development Environment¶
A step by step guide for setting up a development environment for BPF can be found below for both Fedora and Ubuntu. This will guide you through building, installing and testing a development kernel as well as building and installing iproute2.
The step of manually building iproute2 and Linux kernel is usually not necessary given that major distributions already ship recent enough kernels by default, but would be needed for testing bleeding edge versions or contributing BPF patches to iproute2 and to the Linux kernel, respectively. Similarly, for debugging and introspection purposes building bpftool is optional, but recommended.
Fedora¶
The following applies to Fedora 25 or later:
$ sudo dnf install -y git gcc ncurses-devel elfutils-libelf-devel bc \
openssl-devel libcap-devel clang llvm graphviz bison flex glibc-static
Note
If you are running some other Fedora derivative and dnf is missing,
try using yum instead.
Ubuntu¶
The following applies to Ubuntu 17.04 or later:
$ sudo apt-get install -y make gcc libssl-dev bc libelf-dev libcap-dev \
clang gcc-multilib llvm libncurses5-dev git pkg-config libmnl-dev bison flex \
graphviz
openSUSE Tumbleweed¶
The following applies to openSUSE Tumbleweed and openSUSE Leap 15.0 or later:
$ sudo zypper install -y git gcc ncurses-devel libelf-devel bc libopenssl-devel \
libcap-devel clang llvm graphviz bison flex glibc-devel-static
Compiling the Kernel¶
Development of new BPF features for the Linux kernel happens inside the net-next
git tree, latest BPF fixes in the net tree. The following command will obtain
the kernel source for the net-next tree through git:
$ git clone git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git
If the git commit history is not of interest, then --depth 1 will clone the
tree much faster by truncating the git history only to the most recent commit.
In case the net tree is of interest, it can be cloned from this url:
$ git clone git://git.kernel.org/pub/scm/linux/kernel/git/davem/net.git
There are dozens of tutorials in the Internet on how to build Linux kernels, one good resource is the Kernel Newbies website (https://kernelnewbies.org/KernelBuild) that can be followed with one of the two git trees mentioned above.
Make sure that the generated .config file contains the following CONFIG_*
entries for running BPF. These entries are also needed for Cilium.
CONFIG_CGROUP_BPF=y
CONFIG_BPF=y
CONFIG_BPF_SYSCALL=y
CONFIG_NET_SCH_INGRESS=m
CONFIG_NET_CLS_BPF=m
CONFIG_NET_CLS_ACT=y
CONFIG_BPF_JIT=y
CONFIG_LWTUNNEL_BPF=y
CONFIG_HAVE_EBPF_JIT=y
CONFIG_BPF_EVENTS=y
CONFIG_TEST_BPF=m
Some of the entries cannot be adjusted through make menuconfig. For example,
CONFIG_HAVE_EBPF_JIT is selected automatically if a given architecture does
come with an eBPF JIT. In this specific case, CONFIG_HAVE_EBPF_JIT is optional
but highly recommended. An architecture not having an eBPF JIT compiler will need
to fall back to the in-kernel interpreter with the cost of being less efficient
executing BPF instructions.
Verifying the Setup¶
After you have booted into the newly compiled kernel, navigate to the BPF selftest suite in order to test BPF functionality (current working directory points to the root of the cloned git tree):
$ cd tools/testing/selftests/bpf/
$ make
$ sudo ./test_verifier
The verifier tests print out all the current checks being performed. The summary at the end of running all tests will dump information of test successes and failures:
Summary: 847 PASSED, 0 SKIPPED, 0 FAILED
Note
For kernel releases 4.16+ the BPF selftest has a dependency on LLVM 6.0+ caused by the BPF function calls which do not need to be inlined anymore. See section BPF to BPF Calls or the cover letter mail from the kernel patch (https://lwn.net/Articles/741773/) for more information. Not every BPF program has a dependency on LLVM 6.0+ if it does not use this new feature. If your distribution does not provide LLVM 6.0+ you may compile it by following the instruction in the LLVM section.
In order to run through all BPF selftests, the following command is needed:
$ sudo make run_tests
If you see any failures, please contact us on Slack with the full test output.
Compiling iproute2¶
Similar to the net (fixes only) and net-next (new features) kernel trees,
the iproute2 git tree has two branches, namely master and net-next. The
master branch is based on the net tree and the net-next branch is
based against the net-next kernel tree. This is necessary, so that changes
in header files can be synchronized in the iproute2 tree.
In order to clone the iproute2 master branch, the following command can
be used:
$ git clone git://git.kernel.org/pub/scm/linux/kernel/git/iproute2/iproute2.git
Similarly, to clone into mentioned net-next branch of iproute2, run the
following:
$ git clone -b net-next git://git.kernel.org/pub/scm/linux/kernel/git/iproute2/iproute2.git
After that, proceed with the build and installation:
$ cd iproute2/
$ ./configure --prefix=/usr
TC schedulers
ATM no
libc has setns: yes
SELinux support: yes
ELF support: yes
libmnl support: no
Berkeley DB: no
docs: latex: no
WARNING: no docs can be built from LaTeX files
sgml2html: no
WARNING: no HTML docs can be built from SGML
$ make
[...]
$ sudo make install
Ensure that the configure script shows ELF support: yes, so that iproute2
can process ELF files from LLVM’s BPF back end. libelf was listed in the instructions
for installing the dependencies in case of Fedora and Ubuntu earlier.
Compiling bpftool¶
bpftool is an essential tool around debugging and introspection of BPF programs
and maps. It is part of the kernel tree and available under tools/bpf/bpftool/.
Make sure to have cloned either the net or net-next kernel tree as described
earlier. In order to build and install bpftool, the following steps are required:
$ cd <kernel-tree>/tools/bpf/bpftool/
$ make
Auto-detecting system features:
... libbfd: [ on ]
... disassembler-four-args: [ OFF ]
CC xlated_dumper.o
CC prog.o
CC common.o
CC cgroup.o
CC main.o
CC json_writer.o
CC cfg.o
CC map.o
CC jit_disasm.o
CC disasm.o
make[1]: Entering directory '/home/foo/trees/net/tools/lib/bpf'
Auto-detecting system features:
... libelf: [ on ]
... bpf: [ on ]
CC libbpf.o
CC bpf.o
CC nlattr.o
LD libbpf-in.o
LINK libbpf.a
make[1]: Leaving directory '/home/foo/trees/bpf/tools/lib/bpf'
LINK bpftool
$ sudo make install
LLVM¶
LLVM is currently the only compiler suite providing a BPF back end. gcc does not support BPF at this point.
The BPF back end was merged into LLVM’s 3.7 release. Major distributions enable the BPF back end by default when they package LLVM, therefore installing clang and llvm is sufficient on most recent distributions to start compiling C into BPF object files.
The typical workflow is that BPF programs are written in C, compiled by LLVM into object / ELF files, which are parsed by user space BPF ELF loaders (such as iproute2 or others), and pushed into the kernel through the BPF system call. The kernel verifies the BPF instructions and JITs them, returning a new file descriptor for the program, which then can be attached to a subsystem (e.g. networking). If supported, the subsystem could then further offload the BPF program to hardware (e.g. NIC).
For LLVM, BPF target support can be checked, for example, through the following:
$ llc --version
LLVM (http://llvm.org/):
LLVM version 3.8.1
Optimized build.
Default target: x86_64-unknown-linux-gnu
Host CPU: skylake
Registered Targets:
[...]
bpf - BPF (host endian)
bpfeb - BPF (big endian)
bpfel - BPF (little endian)
[...]
By default, the bpf target uses the endianness of the CPU it compiles on,
meaning that if the CPU’s endianness is little endian, the program is represented
in little endian format as well, and if the CPU’s endianness is big endian,
the program is represented in big endian. This also matches the runtime behavior
of BPF, which is generic and uses the CPU’s endianness it runs on in order
to not disadvantage architectures in any of the format.
For cross-compilation, the two targets bpfeb and bpfel were introduced,
thanks to that BPF programs can be compiled on a node running in one endianness
(e.g. little endian on x86) and run on a node in another endianness format (e.g.
big endian on arm). Note that the front end (clang) needs to run in the target
endianness as well.
Using bpf as a target is the preferred way in situations where no mixture of
endianness applies. For example, compilation on x86_64 results in the same
output for the targets bpf and bpfel due to being little endian, therefore
scripts triggering a compilation also do not have to be endian aware.
A minimal, stand-alone XDP drop program might look like the following example
(xdp-example.c):
#include <linux/bpf.h>
#ifndef __section
# define __section(NAME) \
__attribute__((section(NAME), used))
#endif
__section("prog")
int xdp_drop(struct xdp_md *ctx)
{
return XDP_DROP;
}
char __license[] __section("license") = "GPL";
It can then be compiled and loaded into the kernel as follows:
$ clang -O2 -Wall -target bpf -c xdp-example.c -o xdp-example.o
# ip link set dev em1 xdp obj xdp-example.o
Note
Attaching an XDP BPF program to a network device as above requires Linux 4.11 with a device that supports XDP, or Linux 4.12 or later.
For the generated object file LLVM (>= 3.9) uses the official BPF machine value,
that is, EM_BPF (decimal: 247 / hex: 0xf7). In this example, the program
has been compiled with bpf target under x86_64, therefore LSB (as opposed
to MSB) is shown regarding endianness:
$ file xdp-example.o
xdp-example.o: ELF 64-bit LSB relocatable, *unknown arch 0xf7* version 1 (SYSV), not stripped
readelf -a xdp-example.o will dump further information about the ELF file, which can
sometimes be useful for introspecting generated section headers, relocation entries
and the symbol table.
In the unlikely case where clang and LLVM need to be compiled from scratch, the following commands can be used:
$ git clone http://llvm.org/git/llvm.git
$ cd llvm/tools
$ git clone --depth 1 http://llvm.org/git/clang.git
$ cd ..; mkdir build; cd build
$ cmake .. -DLLVM_TARGETS_TO_BUILD="BPF;X86" -DBUILD_SHARED_LIBS=OFF -DCMAKE_BUILD_TYPE=Release -DLLVM_BUILD_RUNTIME=OFF
$ make -j $(getconf _NPROCESSORS_ONLN)
$ ./bin/llc --version
LLVM (http://llvm.org/):
LLVM version x.y.zsvn
Optimized build.
Default target: x86_64-unknown-linux-gnu
Host CPU: skylake
Registered Targets:
bpf - BPF (host endian)
bpfeb - BPF (big endian)
bpfel - BPF (little endian)
x86 - 32-bit X86: Pentium-Pro and above
x86-64 - 64-bit X86: EM64T and AMD64
$ export PATH=$PWD/bin:$PATH # add to ~/.bashrc
Make sure that --version mentions Optimized build., otherwise the
compilation time for programs when having LLVM in debugging mode will
significantly increase (e.g. by 10x or more).
For debugging, clang can generate the assembler output as follows:
$ clang -O2 -S -Wall -target bpf -c xdp-example.c -o xdp-example.S
$ cat xdp-example.S
.text
.section prog,"ax",@progbits
.globl xdp_drop
.p2align 3
xdp_drop: # @xdp_drop
# BB#0:
r0 = 1
exit
.section license,"aw",@progbits
.globl __license # @__license
__license:
.asciz "GPL"
Starting from LLVM’s release 6.0, there is also assembler parser support. You can program using BPF assembler directly, then use llvm-mc to assemble it into an object file. For example, you can assemble the xdp-example.S listed above back into object file using:
$ llvm-mc -triple bpf -filetype=obj -o xdp-example.o xdp-example.S
Furthermore, more recent LLVM versions (>= 4.0) can also store debugging
information in dwarf format into the object file. This can be done through
the usual workflow by adding -g for compilation.
$ clang -O2 -g -Wall -target bpf -c xdp-example.c -o xdp-example.o
$ llvm-objdump -S -no-show-raw-insn xdp-example.o
xdp-example.o: file format ELF64-BPF
Disassembly of section prog:
xdp_drop:
; {
0: r0 = 1
; return XDP_DROP;
1: exit
The llvm-objdump tool can then annotate the assembler output with the
original C code used in the compilation. The trivial example in this case
does not contain much C code, however, the line numbers shown as 0:
and 1: correspond directly to the kernel’s verifier log.
This means that in case BPF programs get rejected by the verifier, llvm-objdump
can help to correlate the instructions back to the original C code, which is
highly useful for analysis.
# ip link set dev em1 xdp obj xdp-example.o verb
Prog section 'prog' loaded (5)!
- Type: 6
- Instructions: 2 (0 over limit)
- License: GPL
Verifier analysis:
0: (b7) r0 = 1
1: (95) exit
processed 2 insns
As it can be seen in the verifier analysis, the llvm-objdump output dumps
the same BPF assembler code as the kernel.
Leaving out the -no-show-raw-insn option will also dump the raw
struct bpf_insn as hex in front of the assembly:
$ llvm-objdump -S xdp-example.o
xdp-example.o: file format ELF64-BPF
Disassembly of section prog:
xdp_drop:
; {
0: b7 00 00 00 01 00 00 00 r0 = 1
; return foo();
1: 95 00 00 00 00 00 00 00 exit
For LLVM IR debugging, the compilation process for BPF can be split into
two steps, generating a binary LLVM IR intermediate file xdp-example.bc, which
can later on be passed to llc:
$ clang -O2 -Wall -target bpf -emit-llvm -c xdp-example.c -o xdp-example.bc
$ llc xdp-example.bc -march=bpf -filetype=obj -o xdp-example.o
The generated LLVM IR can also be dumped in human readable format through:
$ clang -O2 -Wall -emit-llvm -S -c xdp-example.c -o -
LLVM is able to attach debug information such as the description of used data types in the program to the generated BPF object file. By default this is in DWARF format.
A heavily simplified version used by BPF is called BTF (BPF Type Format). The resulting DWARF can be converted into BTF and is later on loaded into the kernel through BPF object loaders. The kernel will then verify the BTF data for correctness and keeps track of the data types the BTF data is containing.
BPF maps can then be annotated with key and value types out of the BTF data such that a later dump of the map exports the map data along with the related type information. This allows for better introspection, debugging and value pretty printing. Note that BTF data is a generic debugging data format and as such any DWARF to BTF converted data can be loaded (e.g. kernel’s vmlinux DWARF data could be converted to BTF and loaded). Latter is in particular useful for BPF tracing in the future.
In order to generate BTF from DWARF debugging information, elfutils (>= 0.173)
is needed. If that is not available, then adding the -mattr=dwarfris option
to the llc command is required during compilation:
$ llc -march=bpf -mattr=help |& grep dwarfris
dwarfris - Disable MCAsmInfo DwarfUsesRelocationsAcrossSections.
[...]
The reason using -mattr=dwarfris is because the flag dwarfris (dwarf
relocation in section) disables DWARF cross-section relocations between DWARF
and the ELF’s symbol table since libdw does not have proper BPF relocation
support, and therefore tools like pahole would otherwise not be able to
properly dump structures from the object.
elfutils (>= 0.173) implements proper BPF relocation support and therefore
the same can be achieved without the -mattr=dwarfris option. Dumping
the structures from the object file could be done from either DWARF or BTF
information. pahole uses the LLVM emitted DWARF information at this
point, however, future pahole versions could rely on BTF if available.
For converting DWARF into BTF, a recent pahole version (>= 1.12) is required. A recent pahole version can also be obtained from its official git repository if not available from one of the distribution packages:
$ git clone https://git.kernel.org/pub/scm/devel/pahole/pahole.git
pahole comes with the option -J to convert DWARF into BTF from an
object file. pahole can be probed for BTF support as follows (note that
the llvm-objcopy tool is required for pahole as well, so check its
presence, too):
$ pahole --help | grep BTF
-J, --btf_encode Encode as BTF
Generating debugging information also requires the front end to generate
source level debug information by passing -g to the clang command
line. Note that -g is needed independently of whether llc’s
dwarfris option is used. Full example for generating the object file:
$ clang -O2 -g -Wall -target bpf -emit-llvm -c xdp-example.c -o xdp-example.bc
$ llc xdp-example.bc -march=bpf -mattr=dwarfris -filetype=obj -o xdp-example.o
Alternatively, by using clang only to build a BPF program with debugging information (again, the dwarfris flag can be omitted when having proper elfutils version):
$ clang -target bpf -O2 -g -c -Xclang -target-feature -Xclang +dwarfris -c xdp-example.c -o xdp-example.o
After successful compilation pahole can be used to properly dump structures
of the BPF program based on the DWARF information:
$ pahole xdp-example.o
struct xdp_md {
__u32 data; /* 0 4 */
__u32 data_end; /* 4 4 */
__u32 data_meta; /* 8 4 */
/* size: 12, cachelines: 1, members: 3 */
/* last cacheline: 12 bytes */
};
Through the option -J pahole can eventually generate the BTF from
DWARF. In the object file DWARF data will still be retained alongside the
newly added BTF data. Full clang and pahole example combined:
$ clang -target bpf -O2 -Wall -g -c -Xclang -target-feature -Xclang +dwarfris -c xdp-example.c -o xdp-example.o
$ pahole -J xdp-example.o
The presence of a .BTF section can be seen through readelf tool:
$ readelf -a xdp-example.o
[...]
[18] .BTF PROGBITS 0000000000000000 00000671
[...]
BPF loaders such as iproute2 will detect and load the BTF section, so that BPF maps can be annotated with type information.
LLVM by default uses the BPF base instruction set for generating code in order to make sure that the generated object file can also be loaded with older kernels such as long-term stable kernels (e.g. 4.9+).
However, LLVM has a -mcpu selector for the BPF back end in order to
select different versions of the BPF instruction set, namely instruction
set extensions on top of the BPF base instruction set in order to generate
more efficient and smaller code.
Available -mcpu options can be queried through:
$ llc -march bpf -mcpu=help
Available CPUs for this target:
generic - Select the generic processor.
probe - Select the probe processor.
v1 - Select the v1 processor.
v2 - Select the v2 processor.
[...]
The generic processor is the default processor, which is also the
base instruction set v1 of BPF. Options v1 and v2 are typically
useful in an environment where the BPF program is being cross compiled
and the target host where the program is loaded differs from the one
where it is compiled (and thus available BPF kernel features might differ
as well).
The recommended -mcpu option which is also used by Cilium internally is
-mcpu=probe! Here, the LLVM BPF back end queries the kernel for availability
of BPF instruction set extensions and when found available, LLVM will use
them for compiling the BPF program whenever appropriate.
A full command line example with llc’s -mcpu=probe:
$ clang -O2 -Wall -target bpf -emit-llvm -c xdp-example.c -o xdp-example.bc
$ llc xdp-example.bc -march=bpf -mcpu=probe -filetype=obj -o xdp-example.o
Generally, LLVM IR generation is architecture independent. There are
however a few differences when using clang -target bpf versus
leaving -target bpf out and thus using clang’s default target which,
depending on the underlying architecture, might be x86_64, arm64
or others.
Quoting from the kernel’s Documentation/bpf/bpf_devel_QA.txt:
- BPF programs may recursively include header file(s) with file scope inline assembly codes. The default target can handle this well, while bpf target may fail if bpf backend assembler does not understand these assembly codes, which is true in most cases.
- When compiled without -g, additional elf sections, e.g.,
.eh_frameand.rela.eh_frame, may be present in the object file with default target, but not with bpf target. - The default target may turn a C switch statement into a switch table
lookup and jump operation. Since the switch table is placed in the
global read-only section, the bpf program will fail to load.
The bpf target does not support switch table optimization. The clang
option
-fno-jump-tablescan be used to disable switch table generation. - For clang
-target bpf, it is guaranteed that pointer or long / unsigned long types will always have a width of 64 bit, no matter whether underlying clang binary or default target (or kernel) is 32 bit. However, when native clang target is used, then it will compile these types based on the underlying architecture’s conventions, meaning in case of 32 bit architecture, pointer or long / unsigned long types e.g. in BPF context structure will have width of 32 bit while the BPF LLVM back end still operates in 64 bit.
The native target is mostly needed in tracing for the case of walking
the kernel’s struct pt_regs that maps CPU registers, or other kernel
structures where CPU’s register width matters. In all other cases such
as networking, the use of clang -target bpf is the preferred choice.
Also, LLVM started to support 32-bit subregisters and BPF ALU32 instructions since
LLVM’s release 7.0. A new code generation attribute alu32 is added. When it is
enabled, LLVM will try to use 32-bit subregisters whenever possible, typically
when there are operations on 32-bit types. The associated ALU instructions with
32-bit subregisters will become ALU32 instructions. For example, for the
following sample code:
$ cat 32-bit-example.c
void cal(unsigned int *a, unsigned int *b, unsigned int *c)
{
unsigned int sum = *a + *b;
*c = sum;
}
At default code generation, the assembler will looks like:
$ clang -target bpf -emit-llvm -S 32-bit-example.c
$ llc -march=bpf 32-bit-example.ll
$ cat 32-bit-example.s
cal:
r1 = *(u32 *)(r1 + 0)
r2 = *(u32 *)(r2 + 0)
r2 += r1
*(u32 *)(r3 + 0) = r2
exit
64-bit registers are used, hence the addition means 64-bit addition. Now, if you
enable the new 32-bit subregisters support by specifying -mattr=+alu32, then
the assembler will looks like:
$ llc -march=bpf -mattr=+alu32 32-bit-example.ll
$ cat 32-bit-example.s
cal:
w1 = *(u32 *)(r1 + 0)
w2 = *(u32 *)(r2 + 0)
w2 += w1
*(u32 *)(r3 + 0) = w2
exit
w register, meaning 32-bit subregister, will be used instead of 64-bit r
register.
Enable 32-bit subregisters might help reducing type extension instruction sequences. It could also help kernel eBPF JIT compiler for 32-bit architectures for which registers pairs are used to model the 64-bit eBPF registers and extra instructions are needed for manipulating the high 32-bit. Given read from 32-bit subregister is guaranteed to read from low 32-bit only even though write still needs to clear the high 32-bit, if the JIT compiler has known the definition of one register only has subregister reads, then instructions for setting the high 32-bit of the destination could be eliminated.
When writing C programs for BPF, there are a couple of pitfalls to be aware of, compared to usual application development with C. The following items describe some of the differences for the BPF model:
Everything needs to be inlined, there are no function calls (on older LLVM versions) or shared library calls available.
Shared libraries, etc cannot be used with BPF. However, common library code used in BPF programs can be placed into header files and included in the main programs. For example, Cilium makes heavy use of it (see
bpf/lib/). However, this still allows for including header files, for example, from the kernel or other libraries and reuse their static inline functions or macros / definitions.Unless a recent kernel (4.16+) and LLVM (6.0+) is used where BPF to BPF function calls are supported, then LLVM needs to compile and inline the entire code into a flat sequence of BPF instructions for a given program section. In such case, best practice is to use an annotation like
__inlinefor every library function as shown below. The use ofalways_inlineis recommended, since the compiler could still decide to uninline large functions that are only annotated asinline.In case the latter happens, LLVM will generate a relocation entry into the ELF file, which BPF ELF loaders such as iproute2 cannot resolve and will thus produce an error since only BPF maps are valid relocation entries which loaders can process.
#include <linux/bpf.h> #ifndef __section # define __section(NAME) \ __attribute__((section(NAME), used)) #endif #ifndef __inline # define __inline \ inline __attribute__((always_inline)) #endif static __inline int foo(void) { return XDP_DROP; } __section("prog") int xdp_drop(struct xdp_md *ctx) { return foo(); } char __license[] __section("license") = "GPL";
Multiple programs can reside inside a single C file in different sections.
C programs for BPF make heavy use of section annotations. A C file is typically structured into 3 or more sections. BPF ELF loaders use these names to extract and prepare the relevant information in order to load the programs and maps through the bpf system call. For example, iproute2 uses
mapsandlicenseas default section name to find metadata needed for map creation and the license for the BPF program, respectively. On program creation time the latter is pushed into the kernel as well, and enables some of the helper functions which are exposed as GPL only in case the program also holds a GPL compatible license, for examplebpf_ktime_get_ns(),bpf_probe_read()and others.The remaining section names are specific for BPF program code, for example, the below code has been modified to contain two program sections,
ingressandegress. The toy example code demonstrates that both can share a map and common static inline helpers such as theaccount_data()function.The
xdp-example.cexample has been modified to atc-example.cexample that can be loaded with tc and attached to a netdevice’s ingress and egress hook. It accounts the transferred bytes into a map calledacc_map, which has two map slots, one for traffic accounted on the ingress hook, one on the egress hook.#include <linux/bpf.h> #include <linux/pkt_cls.h> #include <stdint.h> #include <iproute2/bpf_elf.h> #ifndef __section # define __section(NAME) \ __attribute__((section(NAME), used)) #endif #ifndef __inline # define __inline \ inline __attribute__((always_inline)) #endif #ifndef lock_xadd # define lock_xadd(ptr, val) \ ((void)__sync_fetch_and_add(ptr, val)) #endif #ifndef BPF_FUNC # define BPF_FUNC(NAME, ...) \ (*NAME)(__VA_ARGS__) = (void *)BPF_FUNC_##NAME #endif static void *BPF_FUNC(map_lookup_elem, void *map, const void *key); struct bpf_elf_map acc_map __section("maps") = { .type = BPF_MAP_TYPE_ARRAY, .size_key = sizeof(uint32_t), .size_value = sizeof(uint32_t), .pinning = PIN_GLOBAL_NS, .max_elem = 2, }; static __inline int account_data(struct __sk_buff *skb, uint32_t dir) { uint32_t *bytes; bytes = map_lookup_elem(&acc_map, &dir); if (bytes) lock_xadd(bytes, skb->len); return TC_ACT_OK; } __section("ingress") int tc_ingress(struct __sk_buff *skb) { return account_data(skb, 0); } __section("egress") int tc_egress(struct __sk_buff *skb) { return account_data(skb, 1); } char __license[] __section("license") = "GPL";
The example also demonstrates a couple of other things which are useful to be aware of when developing programs. The code includes kernel headers, standard C headers and an iproute2 specific header containing the definition of
struct bpf_elf_map. iproute2 has a common BPF ELF loader and as such the definition ofstruct bpf_elf_mapis the very same for XDP and tc typed programs.A
struct bpf_elf_mapentry defines a map in the program and contains all relevant information (such as key / value size, etc) needed to generate a map which is used from the two BPF programs. The structure must be placed into themapssection, so that the loader can find it. There can be multiple map declarations of this type with different variable names, but all must be annotated with__section("maps").The
struct bpf_elf_mapis specific to iproute2. Different BPF ELF loaders can have different formats, for example, the libbpf in the kernel source tree, which is mainly used byperf, has a different specification. iproute2 guarantees backwards compatibility forstruct bpf_elf_map. Cilium follows the iproute2 model.The example also demonstrates how BPF helper functions are mapped into the C code and being used. Here,
map_lookup_elem()is defined by mapping this function into theBPF_FUNC_map_lookup_elemenum value which is exposed as a helper inuapi/linux/bpf.h. When the program is later loaded into the kernel, the verifier checks whether the passed arguments are of the expected type and re-points the helper call into a real function call. Moreover,map_lookup_elem()also demonstrates how maps can be passed to BPF helper functions. Here,&acc_mapfrom themapssection is passed as the first argument tomap_lookup_elem().Since the defined array map is global, the accounting needs to use an atomic operation, which is defined as
lock_xadd(). LLVM maps__sync_fetch_and_add()as a built-in function to the BPF atomic add instruction, that is,BPF_STX | BPF_XADD | BPF_Wfor word sizes.Last but not least, the
struct bpf_elf_maptells that the map is to be pinned asPIN_GLOBAL_NS. This means that tc will pin the map into the BPF pseudo file system as a node. By default, it will be pinned to/sys/fs/bpf/tc/globals/acc_mapfor the given example. Due to thePIN_GLOBAL_NS, the map will be placed under/sys/fs/bpf/tc/globals/.globalsacts as a global namespace that spans across object files. If the example usedPIN_OBJECT_NS, then tc would create a directory that is local to the object file. For example, different C files with BPF code could have the sameacc_mapdefinition as above with aPIN_GLOBAL_NSpinning. In that case, the map will be shared among BPF programs originating from various object files.PIN_NONEwould mean that the map is not placed into the BPF file system as a node, and as a result will not be accessible from user space after tc quits. It would also mean that tc creates two separate map instances for each program, since it cannot retrieve a previously pinned map under that name. Theacc_mappart from the mentioned path is the name of the map as specified in the source code.Thus, upon loading of the
ingressprogram, tc will find that no such map exists in the BPF file system and creates a new one. On success, the map will also be pinned, so that when theegressprogram is loaded through tc, it will find that such map already exists in the BPF file system and will reuse that for theegressprogram. The loader also makes sure in case maps exist with the same name that also their properties (key / value size, etc) match.Just like tc can retrieve the same map, also third party applications can use the
BPF_OBJ_GETcommand from the bpf system call in order to create a new file descriptor pointing to the same map instance, which can then be used to lookup / update / delete map elements.The code can be compiled and loaded via iproute2 as follows:
$ clang -O2 -Wall -target bpf -c tc-example.c -o tc-example.o # tc qdisc add dev em1 clsact # tc filter add dev em1 ingress bpf da obj tc-example.o sec ingress # tc filter add dev em1 egress bpf da obj tc-example.o sec egress # tc filter show dev em1 ingress filter protocol all pref 49152 bpf filter protocol all pref 49152 bpf handle 0x1 tc-example.o:[ingress] direct-action id 1 tag c5f7825e5dac396f # tc filter show dev em1 egress filter protocol all pref 49152 bpf filter protocol all pref 49152 bpf handle 0x1 tc-example.o:[egress] direct-action id 2 tag b2fd5adc0f262714 # mount | grep bpf sysfs on /sys/fs/bpf type sysfs (rw,nosuid,nodev,noexec,relatime,seclabel) bpf on /sys/fs/bpf type bpf (rw,relatime,mode=0700) # tree /sys/fs/bpf/ /sys/fs/bpf/ +-- ip -> /sys/fs/bpf/tc/ +-- tc | +-- globals | +-- acc_map +-- xdp -> /sys/fs/bpf/tc/ 4 directories, 1 fileAs soon as packets pass the
em1device, counters from the BPF map will be increased.
- There are no global variables allowed.
For the reasons already mentioned in point 1, BPF cannot have global variables as often used in normal C programs.
However, there is a work-around in that the program can simply use a BPF map of type
BPF_MAP_TYPE_PERCPU_ARRAYwith just a single slot of arbitrary value size. This works, because during execution, BPF programs are guaranteed to never get preempted by the kernel and therefore can use the single map entry as a scratch buffer for temporary data, for example, to extend beyond the stack limitation. This also functions across tail calls, since it has the same guarantees with regards to preemption.Otherwise, for holding state across multiple BPF program runs, normal BPF maps can be used.
- There are no const strings or arrays allowed.
Defining
conststrings or other arrays in the BPF C program does not work for the same reasons as pointed out in sections 1 and 3, which is, that relocation entries will be generated in the ELF file which will be rejected by loaders due to not being part of the ABI towards loaders (loaders also cannot fix up such entries as it would require large rewrites of the already compiled BPF sequence).In the future, LLVM might detect these occurrences and early throw an error to the user.
Helper functions such as
trace_printk()can be worked around as follows:static void BPF_FUNC(trace_printk, const char *fmt, int fmt_size, ...); #ifndef printk # define printk(fmt, ...) \ ({ \ char ____fmt[] = fmt; \ trace_printk(____fmt, sizeof(____fmt), ##__VA_ARGS__); \ }) #endifThe program can then use the macro naturally like
printk("skb len:%u\n", skb->len);. The output will then be written to the trace pipe.tc exec bpf dbgcan be used to retrieve the messages from there.The use of the
trace_printk()helper function has a couple of disadvantages and thus is not recommended for production usage. Constant strings like the"skb len:%u\n"need to be loaded into the BPF stack each time the helper function is called, but also BPF helper functions are limited to a maximum of 5 arguments. This leaves room for only 3 additional variables which can be passed for dumping.Therefore, despite being helpful for quick debugging, it is recommended (for networking programs) to use the
skb_event_output()or thexdp_event_output()helper, respectively. They allow for passing custom structs from the BPF program to the perf event ring buffer along with an optional packet sample. For example, Cilium’s monitor makes use of these helpers in order to implement a debugging framework, notifications for network policy violations, etc. These helpers pass the data through a lockless memory mapped per-CPUperfring buffer, and is thus significantly faster thantrace_printk().
- Use of LLVM built-in functions for memset()/memcpy()/memmove()/memcmp().
Since BPF programs cannot perform any function calls other than those to BPF helpers, common library code needs to be implemented as inline functions. In addition, also LLVM provides some built-ins that the programs can use for constant sizes (here:
n) which will then always get inlined:#ifndef memset # define memset(dest, chr, n) __builtin_memset((dest), (chr), (n)) #endif #ifndef memcpy # define memcpy(dest, src, n) __builtin_memcpy((dest), (src), (n)) #endif #ifndef memmove # define memmove(dest, src, n) __builtin_memmove((dest), (src), (n)) #endifThe
memcmp()built-in had some corner cases where inlining did not take place due to an LLVM issue in the back end, and is therefore not recommended to be used until the issue is fixed.
- There are no loops available (yet).
The BPF verifier in the kernel checks that a BPF program does not contain loops by performing a depth first search of all possible program paths besides other control flow graph validations. The purpose is to make sure that the program is always guaranteed to terminate.
A very limited form of looping is available for constant upper loop bounds by using
#pragma unrolldirective. Example code that is compiled to BPF:#pragma unroll for (i = 0; i < IPV6_MAX_HEADERS; i++) { switch (nh) { case NEXTHDR_NONE: return DROP_INVALID_EXTHDR; case NEXTHDR_FRAGMENT: return DROP_FRAG_NOSUPPORT; case NEXTHDR_HOP: case NEXTHDR_ROUTING: case NEXTHDR_AUTH: case NEXTHDR_DEST: if (skb_load_bytes(skb, l3_off + len, &opthdr, sizeof(opthdr)) < 0) return DROP_INVALID; nh = opthdr.nexthdr; if (nh == NEXTHDR_AUTH) len += ipv6_authlen(&opthdr); else len += ipv6_optlen(&opthdr); break; default: *nexthdr = nh; return len; } }Another possibility is to use tail calls by calling into the same program again and using a
BPF_MAP_TYPE_PERCPU_ARRAYmap for having a local scratch space. While being dynamic, this form of looping however is limited to a maximum of 32 iterations.In the future, BPF may have some native, but limited form of implementing loops.
- Partitioning programs with tail calls.
Tail calls provide the flexibility to atomically alter program behavior during runtime by jumping from one BPF program into another. In order to select the next program, tail calls make use of program array maps (
BPF_MAP_TYPE_PROG_ARRAY), and pass the map as well as the index to the next program to jump to. There is no return to the old program after the jump has been performed, and in case there was no program present at the given map index, then execution continues on the original program.For example, this can be used to implement various stages of a parser, where such stages could be updated with new parsing features during runtime.
Another use case are event notifications, for example, Cilium can opt in packet drop notifications during runtime, where the
skb_event_output()call is located inside the tail called program. Thus, during normal operations, the fall-through path will always be executed unless a program is added to the related map index, where the program then prepares the metadata and triggers the event notification to a user space daemon.Program array maps are quite flexible, enabling also individual actions to be implemented for programs located in each map index. For example, the root program attached to XDP or tc could perform an initial tail call to index 0 of the program array map, performing traffic sampling, then jumping to index 1 of the program array map, where firewalling policy is applied and the packet either dropped or further processed in index 2 of the program array map, where it is mangled and sent out of an interface again. Jumps in the program array map can, of course, be arbitrary. The kernel will eventually execute the fall-through path when the maximum tail call limit has been reached.
Minimal example extract of using tail calls:
[...] #ifndef __stringify # define __stringify(X) #X #endif #ifndef __section # define __section(NAME) \ __attribute__((section(NAME), used)) #endif #ifndef __section_tail # define __section_tail(ID, KEY) \ __section(__stringify(ID) "/" __stringify(KEY)) #endif #ifndef BPF_FUNC # define BPF_FUNC(NAME, ...) \ (*NAME)(__VA_ARGS__) = (void *)BPF_FUNC_##NAME #endif #define BPF_JMP_MAP_ID 1 static void BPF_FUNC(tail_call, struct __sk_buff *skb, void *map, uint32_t index); struct bpf_elf_map jmp_map __section("maps") = { .type = BPF_MAP_TYPE_PROG_ARRAY, .id = BPF_JMP_MAP_ID, .size_key = sizeof(uint32_t), .size_value = sizeof(uint32_t), .pinning = PIN_GLOBAL_NS, .max_elem = 1, }; __section_tail(JMP_MAP_ID, 0) int looper(struct __sk_buff *skb) { printk("skb cb: %u\n", skb->cb[0]++); tail_call(skb, &jmp_map, 0); return TC_ACT_OK; } __section("prog") int entry(struct __sk_buff *skb) { skb->cb[0] = 0; tail_call(skb, &jmp_map, 0); return TC_ACT_OK; } char __license[] __section("license") = "GPL";When loading this toy program, tc will create the program array and pin it to the BPF file system in the global namespace under
jmp_map. Also, the BPF ELF loader in iproute2 will also recognize sections that are marked as__section_tail(). The providedidinstruct bpf_elf_mapwill be matched against the id marker in the__section_tail(), that is,JMP_MAP_ID, and the program therefore loaded at the user specified program array map index, which is0in this example. As a result, all provided tail call sections will be populated by the iproute2 loader to the corresponding maps. This mechanism is not specific to tc, but can be applied with any other BPF program type that iproute2 supports (such as XDP, lwt).The generated elf contains section headers describing the map id and the entry within that map:
$ llvm-objdump -S --no-show-raw-insn prog_array.o | less prog_array.o: file format ELF64-BPF Disassembly of section 1/0: looper: 0: r6 = r1 1: r2 = *(u32 *)(r6 + 48) 2: r1 = r2 3: r1 += 1 4: *(u32 *)(r6 + 48) = r1 5: r1 = 0 ll 7: call -1 8: r1 = r6 9: r2 = 0 ll 11: r3 = 0 12: call 12 13: r0 = 0 14: exit Disassembly of section prog: entry: 0: r2 = 0 1: *(u32 *)(r1 + 48) = r2 2: r2 = 0 ll 4: r3 = 0 5: call 12 6: r0 = 0 7: exiIn this case, the
section 1/0indicates that thelooper()function resides in the map id1at position0.The pinned map can be retrieved by a user space applications (e.g. Cilium daemon), but also by tc itself in order to update the map with new programs. Updates happen atomically, the initial entry programs that are triggered first from the various subsystems are also updated atomically.
Example for tc to perform tail call map updates:
# tc exec bpf graft m:globals/jmp_map key 0 obj new.o sec fooIn case iproute2 would update the pinned program array, the
graftcommand can be used. By pointing it toglobals/jmp_map, tc will update the map at index / key0with a new program residing in the object filenew.ounder sectionfoo.
- Limited stack space of maximum 512 bytes.
Stack space in BPF programs is limited to only 512 bytes, which needs to be taken into careful consideration when implementing BPF programs in C. However, as mentioned earlier in point 3, aBPF_MAP_TYPE_PERCPU_ARRAYmap with a single entry can be used in order to enlarge scratch buffer space.
- Use of BPF inline assembly possible.
LLVM 6.0 or later allows use of inline assembly for BPF for the rare cases where it might be needed. The following (nonsense) toy example shows a 64 bit atomic add. Due to lack of documentation, LLVM source code in
lib/Target/BPF/BPFInstrInfo.tdas well astest/CodeGen/BPF/might be helpful for providing some additional examples. Test code:#include <linux/bpf.h> #ifndef __section # define __section(NAME) \ __attribute__((section(NAME), used)) #endif __section("prog") int xdp_test(struct xdp_md *ctx) { __u64 a = 2, b = 3, *c = &a; /* just a toy xadd example to show the syntax */ asm volatile("lock *(u64 *)(%0+0) += %1" : "=r"(c) : "r"(b), "0"(c)); return a; } char __license[] __section("license") = "GPL";The above program is compiled into the following sequence of BPF instructions:
Verifier analysis: 0: (b7) r1 = 2 1: (7b) *(u64 *)(r10 -8) = r1 2: (b7) r1 = 3 3: (bf) r2 = r10 4: (07) r2 += -8 5: (db) lock *(u64 *)(r2 +0) += r1 6: (79) r0 = *(u64 *)(r10 -8) 7: (95) exit processed 8 insns (limit 131072), stack depth 8
- Remove struct padding with aligning members by using #pragma pack.
In modern compilers, data structures are aligned by default to access memory efficiently. Structure members are aligned to memory address that multiples their size, and padding is added for the proper alignment. Because of this, the size of struct may often grow larger than expected.
struct called_info { u64 start; // 8-byte u64 end; // 8-byte u32 sector; // 4-byte }; // size of 20-byte ? printf("size of %d-byte\n", sizeof(struct called_info)); // size of 24-byte // Actual compiled composition of struct called_info // 0x0(0) 0x8(8) // ↓________________________↓ // | start (8) | // |________________________| // | end (8) | // |________________________| // | sector(4) | PADDING | <= address aligned to 8 // |____________|___________| with 4-byte PADDING.The BPF verifier in the kernel checks the stack boundary that a BPF program does not access outside of boundary or uninitialized stack area. Using struct with the padding as a map value, will cause
invalid indirect read from stackfailure onbpf_prog_load().Example code:
struct called_info { u64 start; u64 end; u32 sector; }; struct bpf_map_def SEC("maps") called_info_map = { .type = BPF_MAP_TYPE_HASH, .key_size = sizeof(long), .value_size = sizeof(struct called_info), .max_entries = 4096, }; SEC("kprobe/submit_bio") int submit_bio_entry(struct pt_regs *ctx) { char fmt[] = "submit_bio(bio=0x%lx) called: %llu\n"; u64 start_time = bpf_ktime_get_ns(); long bio_ptr = PT_REGS_PARM1(ctx); struct called_info called_info = { .start = start_time, .end = 0, .bi_sector = 0 }; bpf_map_update_elem(&called_info_map, &bio_ptr, &called_info, BPF_ANY); bpf_trace_printk(fmt, sizeof(fmt), bio_ptr, start_time); return 0; } // On bpf_load_program bpf_load_program() err=13 0: (bf) r6 = r1 ... 19: (b7) r1 = 0 20: (7b) *(u64 *)(r10 -72) = r1 21: (7b) *(u64 *)(r10 -80) = r7 22: (63) *(u32 *)(r10 -64) = r1 ... 30: (85) call bpf_map_update_elem#2 invalid indirect read from stack off -80+20 size 24At
bpf_prog_load(), an eBPF verifierbpf_check()is called, and it’ll check stack boundary by callingcheck_func_arg() -> check_stack_boundary(). From the upper error shows,struct called_infois compiled to 24-byte size, and the message says reading a data from +20 is an invalid indirect read. And as we discussed earlier, the address 0x14(20) is the place where PADDING is.// Actual compiled composition of struct called_info // 0x10(16) 0x14(20) 0x18(24) // ↓____________↓___________↓ // | sector(4) | PADDING | <= address aligned to 8 // |____________|___________| with 4-byte PADDING.The
check_stack_boundary()internally loops through the everyaccess_size(24) byte from the start pointer to make sure that it’s within stack boundary and all elements of the stack are initialized. Since the padding isn’t supposed to be used, it gets the ‘invalid indirect read from stack’ failure. To avoid this kind of failure, remove the padding from the struct is necessary.Removing the padding by using
#pragma pack(n)directive:#pragma pack(4) struct called_info { u64 start; // 8-byte u64 end; // 8-byte u32 sector; // 4-byte }; // size of 20-byte ? printf("size of %d-byte\n", sizeof(struct called_info)); // size of 20-byte // Actual compiled composition of packed struct called_info // 0x0(0) 0x8(8) // ↓________________________↓ // | start (8) | // |________________________| // | end (8) | // |________________________| // | sector(4) | <= address aligned to 4 // |____________| with no PADDING.By locating
#pragma pack(4)before ofstruct called_info, compiler will align members of a struct to the least of 4-byte and their natural alignment. As you can see, the size ofstruct called_infohas been shrunk to 20-byte and the padding is no longer exist.But, removing the padding have downsides either. For example, compiler will generate less optimized code. Since we’ve removed the padding, processors will conduct unaligned access to the structure and this might lead to performance degradation. And also, unaligned access might get rejected by verifier on some architectures.
However, there is a way to avoid downsides of packed structure. By simply adding the explicit padding
u32 padmember at the end will resolve the same problem without packing of the structure.struct called_info { u64 start; // 8-byte u64 end; // 8-byte u32 sector; // 4-byte u32 pad; // 4-byte }; // size of 24-byte ? printf("size of %d-byte\n", sizeof(struct called_info)); // size of 24-byte // Actual compiled composition of struct called_info with explicit padding // 0x0(0) 0x8(8) // ↓________________________↓ // | start (8) | // |________________________| // | end (8) | // |________________________| // | sector(4) | pad (4) | <= address aligned to 8 // |____________|___________| with explicit PADDING.
iproute2¶
There are various front ends for loading BPF programs into the kernel such as bcc,
perf, iproute2 and others. The Linux kernel source tree also provides a user space
library under tools/lib/bpf/, which is mainly used and driven by perf for
loading BPF tracing programs into the kernel. However, the library itself is
generic and not limited to perf only. bcc is a toolkit providing many useful
BPF programs mainly for tracing that are loaded ad-hoc through a Python interface
embedding the BPF C code. Syntax and semantics for implementing BPF programs
slightly differ among front ends in general, though. Additionally, there are also
BPF samples in the kernel source tree (samples/bpf/) which parse the generated
object files and load the code directly through the system call interface.
This and previous sections mainly focus on the iproute2 suite’s BPF front end for loading networking programs of XDP, tc or lwt type, since Cilium’s programs are implemented against this BPF loader. In future, Cilium will be equipped with a native BPF loader, but programs will still be compatible to be loaded through iproute2 suite in order to facilitate development and debugging.
All BPF program types supported by iproute2 share the same BPF loader logic
due to having a common loader back end implemented as a library (lib/bpf.c
in iproute2 source tree).
The previous section on LLVM also covered some iproute2 parts related to writing BPF C programs, and later sections in this document are related to tc and XDP specific aspects when writing programs. Therefore, this section will rather focus on usage examples for loading object files with iproute2 as well as some of the generic mechanics of the loader. It does not try to provide a complete coverage of all details, but enough for getting started.
1. Loading of XDP BPF object files.
Given a BPF object file
prog.ohas been compiled for XDP, it can be loaded throughipto a XDP-supported netdevice calledem1with the following command:# ip link set dev em1 xdp obj prog.oThe above command assumes that the program code resides in the default section which is called
progin XDP case. Should this not be the case, and the section is named differently, for example,foobar, then the program needs to be loaded as:# ip link set dev em1 xdp obj prog.o sec foobarNote that it is also possible to load the program out of the
.textsection. Changing the minimal, stand-alone XDP drop program by removing the__section()annotation from thexdp_dropentry point would look like the following:#include <linux/bpf.h> #ifndef __section # define __section(NAME) \ __attribute__((section(NAME), used)) #endif int xdp_drop(struct xdp_md *ctx) { return XDP_DROP; } char __license[] __section("license") = "GPL";And can be loaded as follows:
# ip link set dev em1 xdp obj prog.o sec .textBy default,
ipwill throw an error in case a XDP program is already attached to the networking interface, to prevent it from being overridden by accident. In order to replace the currently running XDP program with a new one, the-forceoption must be used:# ip -force link set dev em1 xdp obj prog.oMost XDP-enabled drivers today support an atomic replacement of the existing program with a new one without traffic interruption. There is always only a single program attached to an XDP-enabled driver due to performance reasons, hence a chain of programs is not supported. However, as described in the previous section, partitioning of programs can be performed through tail calls to achieve a similar use case when necessary.
The
ip linkcommand will display anxdpflag if the interface has an XDP program attached.ip link | grep xdpcan thus be used to find all interfaces that have XDP running. Further introspection facilities are provided through the detailed view withip -d linkandbpftoolcan be used to retrieve information about the attached program based on the BPF program ID shown in theip linkdump.In order to remove the existing XDP program from the interface, the following command must be issued:
# ip link set dev em1 xdp offIn the case of switching a driver’s operation mode from non-XDP to native XDP and vice versa, typically the driver needs to reconfigure its receive (and transmit) rings in order to ensure received packet are set up linearly within a single page for BPF to read and write into. However, once completed, then most drivers only need to perform an atomic replacement of the program itself when a BPF program is requested to be swapped.
In total, XDP supports three operation modes which iproute2 implements as well:
xdpdrv,xdpoffloadandxdpgeneric.
xdpdrvstands for native XDP, meaning the BPF program is run directly in the driver’s receive path at the earliest possible point in software. This is the normal / conventional XDP mode and requires driver’s to implement XDP support, which all major 10G/40G/+ networking drivers in the upstream Linux kernel already provide.
xdpgenericstands for generic XDP and is intended as an experimental test bed for drivers which do not yet support native XDP. Given the generic XDP hook in the ingress path comes at a much later point in time when the packet already enters the stack’s main receive path as askb, the performance is significantly less than with processing inxdpdrvmode.xdpgenerictherefore is for the most part only interesting for experimenting, less for production environments.Last but not least, the
xdpoffloadmode is implemented by SmartNICs such as those supported by Netronome’s nfp driver and allow for offloading the entire BPF/XDP program into hardware, thus the program is run on each packet reception directly on the card. This provides even higher performance than running in native XDP although not all BPF map types or BPF helper functions are available for use compared to native XDP. The BPF verifier will reject the program in such case and report to the user what is unsupported. Other than staying in the realm of supported BPF features and helper functions, no special precautions have to be taken when writing BPF C programs.When a command like
ip link set dev em1 xdp obj [...]is used, then the kernel will attempt to load the program first as native XDP, and in case the driver does not support native XDP, it will automatically fall back to generic XDP. Thus, for example, using explicitlyxdpdrvinstead ofxdp, the kernel will only attempt to load the program as native XDP and fail in case the driver does not support it, which provides a guarantee that generic XDP is avoided altogether.Example for enforcing a BPF/XDP program to be loaded in native XDP mode, dumping the link details and unloading the program again:
# ip -force link set dev em1 xdpdrv obj prog.o # ip link show [...] 6: em1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 xdp qdisc mq state UP mode DORMANT group default qlen 1000 link/ether be:08:4d:b6:85:65 brd ff:ff:ff:ff:ff:ff prog/xdp id 1 tag 57cd311f2e27366b [...] # ip link set dev em1 xdpdrv offSame example now for forcing generic XDP, even if the driver would support native XDP, and additionally dumping the BPF instructions of the attached dummy program through bpftool:
# ip -force link set dev em1 xdpgeneric obj prog.o # ip link show [...] 6: em1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 xdpgeneric qdisc mq state UP mode DORMANT group default qlen 1000 link/ether be:08:4d:b6:85:65 brd ff:ff:ff:ff:ff:ff prog/xdp id 4 tag 57cd311f2e27366b <-- BPF program ID 4 [...] # bpftool prog dump xlated id 4 <-- Dump of instructions running on em1 0: (b7) r0 = 1 1: (95) exit # ip link set dev em1 xdpgeneric offAnd last but not least offloaded XDP, where we additionally dump program information via bpftool for retrieving general metadata:
# ip -force link set dev em1 xdpoffload obj prog.o # ip link show [...] 6: em1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 xdpoffload qdisc mq state UP mode DORMANT group default qlen 1000 link/ether be:08:4d:b6:85:65 brd ff:ff:ff:ff:ff:ff prog/xdp id 8 tag 57cd311f2e27366b [...] # bpftool prog show id 8 8: xdp tag 57cd311f2e27366b dev em1 <-- Also indicates a BPF program offloaded to em1 loaded_at Apr 11/20:38 uid 0 xlated 16B not jited memlock 4096B # ip link set dev em1 xdpoffload offNote that it is not possible to use
xdpdrvandxdpgenericor other modes at the same time, meaning only one of the XDP operation modes must be picked.A switch between different XDP modes e.g. from generic to native or vice versa is not atomically possible. Only switching programs within a specific operation mode is:
# ip -force link set dev em1 xdpgeneric obj prog.o # ip -force link set dev em1 xdpoffload obj prog.o RTNETLINK answers: File exists # ip -force link set dev em1 xdpdrv obj prog.o RTNETLINK answers: File exists # ip -force link set dev em1 xdpgeneric obj prog.o <-- Succeeds due to xdpgeneric #Switching between modes requires to first leave the current operation mode in order to then enter the new one:
# ip -force link set dev em1 xdpgeneric obj prog.o # ip -force link set dev em1 xdpgeneric off # ip -force link set dev em1 xdpoffload obj prog.o # ip l [...] 6: em1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 xdpoffload qdisc mq state UP mode DORMANT group default qlen 1000 link/ether be:08:4d:b6:85:65 brd ff:ff:ff:ff:ff:ff prog/xdp id 17 tag 57cd311f2e27366b [...] # ip -force link set dev em1 xdpoffload off
2. Loading of tc BPF object files.
Given a BPF object file
prog.ohas been compiled for tc, it can be loaded through the tc command to a netdevice. Unlike XDP, there is no driver dependency for supporting attaching BPF programs to the device. Here, the netdevice is calledem1, and with the following command the program can be attached to the networkingingresspath ofem1:# tc qdisc add dev em1 clsact # tc filter add dev em1 ingress bpf da obj prog.oThe first step is to set up a
clsactqdisc (Linux queueing discipline).clsactis a dummy qdisc similar to theingressqdisc, which can only hold classifier and actions, but does not perform actual queueing. It is needed in order to attach thebpfclassifier. Theclsactqdisc provides two special hooks calledingressandegress, where the classifier can be attached to. Bothingressandegresshooks are located in central receive and transmit locations in the networking data path, where every packet on the device passes through. Theingresshook is called from__netif_receive_skb_core() -> sch_handle_ingress()in the kernel and theegresshook from__dev_queue_xmit() -> sch_handle_egress().The equivalent for attaching the program to the
egresshook looks as follows:# tc filter add dev em1 egress bpf da obj prog.oThe
clsactqdisc is processed lockless fromingressandegressdirection and can also be attached to virtual, queue-less devices such asvethdevices connecting containers.Next to the hook, the
tc filtercommand selectsbpfto be used inda(direct-action) mode.damode is recommended and should always be specified. It basically means that thebpfclassifier does not need to call into external tc action modules, which are not necessary forbpfanyway, since all packet mangling, forwarding or other kind of actions can already be performed inside the single BPF program which is to be attached, and is therefore significantly faster.At this point, the program has been attached and is executed once packets traverse the device. Like in XDP, should the default section name not be used, then it can be specified during load, for example, in case of section
foobar:# tc filter add dev em1 egress bpf da obj prog.o sec foobariproute2’s BPF loader allows for using the same command line syntax across program types, hence the
obj prog.o sec foobaris the same syntax as with XDP mentioned earlier.The attached programs can be listed through the following commands:
# tc filter show dev em1 ingress filter protocol all pref 49152 bpf filter protocol all pref 49152 bpf handle 0x1 prog.o:[ingress] direct-action id 1 tag c5f7825e5dac396f # tc filter show dev em1 egress filter protocol all pref 49152 bpf filter protocol all pref 49152 bpf handle 0x1 prog.o:[egress] direct-action id 2 tag b2fd5adc0f262714The output of
prog.o:[ingress]tells that program sectioningresswas loaded from the fileprog.o, andbpfoperates indirect-actionmode. The programidandtagis appended for each case, where the latter denotes a hash over the instruction stream which can be correlated with the object file orperfreports with stack traces, etc. Last but not least, theidrepresents the system-wide unique BPF program identifier that can be used along withbpftoolto further inspect or dump the attached BPF program.tc can attach more than just a single BPF program, it provides various other classifiers which can be chained together. However, attaching a single BPF program is fully sufficient since all packet operations can be contained in the program itself thanks to
da(direct-action) mode, meaning the BPF program itself will already return the tc action verdict such asTC_ACT_OK,TC_ACT_SHOTand others. For optimal performance and flexibility, this is the recommended usage.In the above
showcommand, tc also displayspref 49152andhandle 0x1next to the BPF related output. Both are auto-generated in case they are not explicitly provided through the command line.prefdenotes a priority number, which means that in case multiple classifiers are attached, they will be executed based on ascending priority, andhandlerepresents an identifier in case multiple instances of the same classifier have been loaded under the samepref. Since in case of BPF, a single program is fully sufficient,prefandhandlecan typically be ignored.Only in the case where it is planned to atomically replace the attached BPF programs, it would be recommended to explicitly specify
prefandhandlea priori on initial load, so that they do not have to be queried at a later point in time for thereplaceoperation. Thus, creation becomes:# tc filter add dev em1 ingress pref 1 handle 1 bpf da obj prog.o sec foobar # tc filter show dev em1 ingress filter protocol all pref 1 bpf filter protocol all pref 1 bpf handle 0x1 prog.o:[foobar] direct-action id 1 tag c5f7825e5dac396fAnd for the atomic replacement, the following can be issued for updating the existing program at
ingresshook with the new BPF program from the fileprog.oin sectionfoobar:# tc filter replace dev em1 ingress pref 1 handle 1 bpf da obj prog.o sec foobarLast but not least, in order to remove all attached programs from the
ingressrespectivelyegresshook, the following can be used:# tc filter del dev em1 ingress # tc filter del dev em1 egressFor removing the entire
clsactqdisc from the netdevice, which implicitly also removes all attached programs from theingressandegresshooks, the below command is provided:# tc qdisc del dev em1 clsacttc BPF programs can also be offloaded if the NIC and driver has support for it similarly as with XDP BPF programs. Netronome’s nfp supported NICs offer both types of BPF offload.
# tc qdisc add dev em1 clsact # tc filter replace dev em1 ingress pref 1 handle 1 bpf skip_sw da obj prog.o Error: TC offload is disabled on net device. We have an error talking to the kernelIf the above error is shown, then tc hardware offload first needs to be enabled for the device through ethtool’s
hw-tc-offloadsetting:# ethtool -K em1 hw-tc-offload on # tc qdisc add dev em1 clsact # tc filter replace dev em1 ingress pref 1 handle 1 bpf skip_sw da obj prog.o # tc filter show dev em1 ingress filter protocol all pref 1 bpf filter protocol all pref 1 bpf handle 0x1 prog.o:[classifier] direct-action skip_sw in_hw id 19 tag 57cd311f2e27366bThe
in_hwflag confirms that the program has been offloaded to the NIC.Note that BPF offloads for both tc and XDP cannot be loaded at the same time, either the tc or XDP offload option must be selected.
3. Testing BPF offload interface via netdevsim driver.
The netdevsim driver which is part of the Linux kernel provides a dummy driver which implements offload interfaces for XDP BPF and tc BPF programs and facilitates testing kernel changes or low-level user space programs implementing a control plane directly against the kernel’s UAPI.
A netdevsim device can be created as follows:
# ip link add dev sim0 type netdevsim # ip link set dev sim0 up # ethtool -K sim0 hw-tc-offload on # ip l [...] 7: sim0: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000 link/ether a2:24:4c:1c:c2:b3 brd ff:ff:ff:ff:ff:ffAfter that step, XDP BPF or tc BPF programs can be test loaded as shown in the various examples earlier:
# ip -force link set dev sim0 xdpoffload obj prog.o # ip l [...] 7: sim0: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 xdpoffload qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000 link/ether a2:24:4c:1c:c2:b3 brd ff:ff:ff:ff:ff:ff prog/xdp id 20 tag 57cd311f2e27366b
These two workflows are the basic operations to load XDP BPF respectively tc BPF programs with iproute2.
There are other various advanced options for the BPF loader that apply both to XDP and tc, some of them are listed here. In the examples only XDP is presented for simplicity.
1. Verbose log output even on success.
The option
verbcan be appended for loading programs in order to dump the verifier log, even if no error occurred:# ip link set dev em1 xdp obj xdp-example.o verb Prog section 'prog' loaded (5)! - Type: 6 - Instructions: 2 (0 over limit) - License: GPL Verifier analysis: 0: (b7) r0 = 1 1: (95) exit processed 2 insns
2. Load program that is already pinned in BPF file system.
Instead of loading a program from an object file, iproute2 can also retrieve the program from the BPF file system in case some external entity pinned it there and attach it to the device:
# ip link set dev em1 xdp pinned /sys/fs/bpf/progiproute2 can also use the short form that is relative to the detected mount point of the BPF file system:
# ip link set dev em1 xdp pinned m:prog
When loading BPF programs, iproute2 will automatically detect the mounted
file system instance in order to perform pinning of nodes. In case no mounted
BPF file system instance was found, then tc will automatically mount it
to the default location under /sys/fs/bpf/.
In case an instance has already been found, then it will be used and no additional mount will be performed:
# mkdir /var/run/bpf # mount --bind /var/run/bpf /var/run/bpf # mount -t bpf bpf /var/run/bpf # tc filter add dev em1 ingress bpf da obj tc-example.o sec prog # tree /var/run/bpf /var/run/bpf +-- ip -> /run/bpf/tc/ +-- tc | +-- globals | +-- jmp_map +-- xdp -> /run/bpf/tc/ 4 directories, 1 file
By default tc will create an initial directory structure as shown above,
where all subsystem users will point to the same location through symbolic
links for the globals namespace, so that pinned BPF maps can be reused
among various BPF program types in iproute2. In case the file system instance
has already been mounted and an existing structure already exists, then tc will
not override it. This could be the case for separating lwt, tc and
xdp maps in order to not share globals among all.
As briefly covered in the previous LLVM section, iproute2 will install a header file upon installation which can be included through the standard include path by BPF programs:
#include <iproute2/bpf_elf.h>
The purpose of this header file is to provide an API for maps and default section names used by programs. It’s a stable contract between iproute2 and BPF programs.
The map definition for iproute2 is struct bpf_elf_map. Its members have
been covered earlier in the LLVM section of this document.
When parsing the BPF object file, the iproute2 loader will walk through
all ELF sections. It initially fetches ancillary sections like maps and
license. For maps, the struct bpf_elf_map array will be checked
for validity and whenever needed, compatibility workarounds are performed.
Subsequently all maps are created with the user provided information, either
retrieved as a pinned object, or newly created and then pinned into the BPF
file system. Next the loader will handle all program sections that contain
ELF relocation entries for maps, meaning that BPF instructions loading
map file descriptors into registers are rewritten so that the corresponding
map file descriptors are encoded into the instructions immediate value, in
order for the kernel to be able to convert them later on into map kernel
pointers. After that all the programs themselves are created through the BPF
system call, and tail called maps, if present, updated with the program’s file
descriptors.
bpftool¶
bpftool is the main introspection and debugging tool around BPF and developed
and shipped along with the Linux kernel tree under tools/bpf/bpftool/.
The tool can dump all BPF programs and maps that are currently loaded in the system, or list and correlate all BPF maps used by a specific program. Furthermore, it allows to dump the entire map’s key / value pairs, or lookup, update, delete individual ones as well as retrieve a key’s neighbor key in the map. Such operations can be performed based on BPF program or map IDs or by specifying the location of a BPF file system pinned program or map. The tool additionally also offers an option to pin maps or programs into the BPF file system.
For a quick overview of all BPF programs currently loaded on the host invoke the following command:
# bpftool prog 398: sched_cls tag 56207908be8ad877 loaded_at Apr 09/16:24 uid 0 xlated 8800B jited 6184B memlock 12288B map_ids 18,5,17,14 399: sched_cls tag abc95fb4835a6ec9 loaded_at Apr 09/16:24 uid 0 xlated 344B jited 223B memlock 4096B map_ids 18 400: sched_cls tag afd2e542b30ff3ec loaded_at Apr 09/16:24 uid 0 xlated 1720B jited 1001B memlock 4096B map_ids 17 401: sched_cls tag 2dbbd74ee5d51cc8 loaded_at Apr 09/16:24 uid 0 xlated 3728B jited 2099B memlock 4096B map_ids 17 [...]
Similarly, to get an overview of all active maps:
# bpftool map 5: hash flags 0x0 key 20B value 112B max_entries 65535 memlock 13111296B 6: hash flags 0x0 key 20B value 20B max_entries 65536 memlock 7344128B 7: hash flags 0x0 key 10B value 16B max_entries 8192 memlock 790528B 8: hash flags 0x0 key 22B value 28B max_entries 8192 memlock 987136B 9: hash flags 0x0 key 20B value 8B max_entries 512000 memlock 49352704B [...]
Note that for each command, bpftool also supports json based output by
appending --json at the end of the command line. An additional
--pretty improves the output to be more human readable.
# bpftool prog --json --pretty
For dumping the post-verifier BPF instruction image of a specific BPF program, one starting point could be to inspect a specific program, e.g. attached to the tc ingress hook:
# tc filter show dev cilium_host egress filter protocol all pref 1 bpf chain 0 filter protocol all pref 1 bpf chain 0 handle 0x1 bpf_host.o:[from-netdev] \ direct-action not_in_hw id 406 tag e0362f5bd9163a0a jited
The program from the object file bpf_host.o, section from-netdev has
a BPF program ID of 406 as denoted in id 406. Based on this information
bpftool can provide some high-level metadata specific to the program:
# bpftool prog show id 406 406: sched_cls tag e0362f5bd9163a0a loaded_at Apr 09/16:24 uid 0 xlated 11144B jited 7721B memlock 12288B map_ids 18,20,8,5,6,14
The program of ID 406 is of type sched_cls (BPF_PROG_TYPE_SCHED_CLS),
has a tag of e0362f5bd9163a0a (SHA sum over the instruction sequence),
it was loaded by root uid 0 on Apr 09/16:24. The BPF instruction
sequence is 11,144 bytes long and the JITed image 7,721 bytes. The
program itself (excluding maps) consumes 12,288 bytes that are accounted /
charged against user uid 0. And the BPF program uses the BPF maps with
IDs 18, 20, 8, 5, 6 and 14. The latter IDs can further
be used to get information or dump the map themselves.
Additionally, bpftool can issue a dump request of the BPF instructions the program runs:
# bpftool prog dump xlated id 406 0: (b7) r7 = 0 1: (63) *(u32 *)(r1 +60) = r7 2: (63) *(u32 *)(r1 +56) = r7 3: (63) *(u32 *)(r1 +52) = r7 [...] 47: (bf) r4 = r10 48: (07) r4 += -40 49: (79) r6 = *(u64 *)(r10 -104) 50: (bf) r1 = r6 51: (18) r2 = map[id:18] <-- BPF map id 18 53: (b7) r5 = 32 54: (85) call bpf_skb_event_output#5656112 <-- BPF helper call 55: (69) r1 = *(u16 *)(r6 +192) [...]
bpftool correlates BPF map IDs into the instruction stream as shown above as well as calls to BPF helpers or other BPF programs.
The instruction dump reuses the same ‘pretty-printer’ as the kernel’s BPF
verifier. Since the program was JITed and therefore the actual JIT image
that was generated out of above xlated instructions is executed, it
can be dumped as well through bpftool:
# bpftool prog dump jited id 406 0: push %rbp 1: mov %rsp,%rbp 4: sub $0x228,%rsp b: sub $0x28,%rbp f: mov %rbx,0x0(%rbp) 13: mov %r13,0x8(%rbp) 17: mov %r14,0x10(%rbp) 1b: mov %r15,0x18(%rbp) 1f: xor %eax,%eax 21: mov %rax,0x20(%rbp) 25: mov 0x80(%rdi),%r9d [...]
Mainly for BPF JIT developers, the option also exists to interleave the disassembly with the actual native opcodes:
# bpftool prog dump jited id 406 opcodes 0: push %rbp 55 1: mov %rsp,%rbp 48 89 e5 4: sub $0x228,%rsp 48 81 ec 28 02 00 00 b: sub $0x28,%rbp 48 83 ed 28 f: mov %rbx,0x0(%rbp) 48 89 5d 00 13: mov %r13,0x8(%rbp) 4c 89 6d 08 17: mov %r14,0x10(%rbp) 4c 89 75 10 1b: mov %r15,0x18(%rbp) 4c 89 7d 18 [...]
The same interleaving can be done for the normal BPF instructions which can sometimes be useful for debugging in the kernel:
# bpftool prog dump xlated id 406 opcodes 0: (b7) r7 = 0 b7 07 00 00 00 00 00 00 1: (63) *(u32 *)(r1 +60) = r7 63 71 3c 00 00 00 00 00 2: (63) *(u32 *)(r1 +56) = r7 63 71 38 00 00 00 00 00 3: (63) *(u32 *)(r1 +52) = r7 63 71 34 00 00 00 00 00 4: (63) *(u32 *)(r1 +48) = r7 63 71 30 00 00 00 00 00 5: (63) *(u32 *)(r1 +64) = r7 63 71 40 00 00 00 00 00 [...]
The basic blocks of a program can also be visualized with the help of
graphviz. For this purpose bpftool has a visual dump mode that
generates a dot file instead of the plain BPF xlated instruction
dump that can later be converted to a png file:
# bpftool prog dump xlated id 406 visual &> output.dot $ dot -Tpng output.dot -o output.png
Another option would be to pass the dot file to dotty as a viewer, that
is dotty output.dot, where the result for the bpf_host.o program
looks as follows (small extract):
Note that the xlated instruction dump provides the post-verifier BPF
instruction image which means that it dumps the instructions as if they
were to be run through the BPF interpreter. In the kernel, the verifier
performs various rewrites of the original instructions provided by the
BPF loader.
One example of rewrites is the inlining of helper functions in order to improve runtime performance, here in the case of a map lookup for hash tables:
# bpftool prog dump xlated id 3 0: (b7) r1 = 2 1: (63) *(u32 *)(r10 -4) = r1 2: (bf) r2 = r10 3: (07) r2 += -4 4: (18) r1 = map[id:2] <-- BPF map id 2 6: (85) call __htab_map_lookup_elem#77408 <-+ BPF helper inlined rewrite 7: (15) if r0 == 0x0 goto pc+2 | 8: (07) r0 += 56 | 9: (79) r0 = *(u64 *)(r0 +0) <-+ 10: (15) if r0 == 0x0 goto pc+24 11: (bf) r2 = r10 12: (07) r2 += -4 [...]
bpftool correlates calls to helper functions or BPF to BPF calls through
kallsyms. Therefore, make sure that JITed BPF programs are exposed to
kallsyms (bpf_jit_kallsyms) and that kallsyms addresses are not
obfuscated (calls are otherwise shown as call bpf_unspec#0):
# echo 0 > /proc/sys/kernel/kptr_restrict # echo 1 > /proc/sys/net/core/bpf_jit_kallsyms
BPF to BPF calls are correlated as well for both, interpreter as well
as JIT case. In the latter, the tag of the subprogram is shown as
call target. In each case, the pc+2 is the pc-relative offset of
the call target, which denotes the subprogram.
# bpftool prog dump xlated id 1 0: (85) call pc+2#__bpf_prog_run_args32 1: (b7) r0 = 1 2: (95) exit 3: (b7) r0 = 2 4: (95) exit
JITed variant of the dump:
# bpftool prog dump xlated id 1 0: (85) call pc+2#bpf_prog_3b185187f1855c4c_F 1: (b7) r0 = 1 2: (95) exit 3: (b7) r0 = 2 4: (95) exit
In the case of tail calls, the kernel maps them into a single instruction internally, bpftool will still correlate them as a helper call for ease of debugging:
# bpftool prog dump xlated id 2 [...] 10: (b7) r2 = 8 11: (85) call bpf_trace_printk#-41312 12: (bf) r1 = r6 13: (18) r2 = map[id:1] 15: (b7) r3 = 0 16: (85) call bpf_tail_call#12 17: (b7) r1 = 42 18: (6b) *(u16 *)(r6 +46) = r1 19: (b7) r0 = 0 20: (95) exit # bpftool map show id 1 1: prog_array flags 0x0 key 4B value 4B max_entries 1 memlock 4096B
Dumping an entire map is possible through the map dump subcommand
which iterates through all present map elements and dumps the key /
value pairs.
If no BTF (BPF Type Format) data is available for a given map, then the key / value pairs are dumped as hex:
# bpftool map dump id 5 key: f0 0d 00 00 00 00 00 00 0a 66 00 00 00 00 8a d6 02 00 00 00 value: 00 00 00 00 00 00 00 00 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 key: 0a 66 1c ee 00 00 00 00 00 00 00 00 00 00 00 00 01 00 00 00 value: 00 00 00 00 00 00 00 00 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [...] Found 6 elements
However, with BTF, the map also holds debugging information about
the key and value structures. For example, BTF in combination with
BPF maps and the BPF_ANNOTATE_KV_PAIR() macro from iproute2 will
result in the following dump (test_xdp_noinline.o from kernel
selftests):
# cat tools/testing/selftests/bpf/test_xdp_noinline.c [...] struct ctl_value { union { __u64 value; __u32 ifindex; __u8 mac[6]; }; }; struct bpf_map_def __attribute__ ((section("maps"), used)) ctl_array = { .type = BPF_MAP_TYPE_ARRAY, .key_size = sizeof(__u32), .value_size = sizeof(struct ctl_value), .max_entries = 16, .map_flags = 0, }; BPF_ANNOTATE_KV_PAIR(ctl_array, __u32, struct ctl_value); [...]
The BPF_ANNOTATE_KV_PAIR() macro forces a map-specific ELF section containing an empty key and value, this enables the iproute2 BPF loader to correlate BTF data with that section and thus allows to choose the corresponding types out of the BTF for loading the map.
Compiling through LLVM and generating BTF through debugging information
by pahole:
# clang [...] -O2 -target bpf -g -emit-llvm -c test_xdp_noinline.c -o - | llc -march=bpf -mcpu=probe -mattr=dwarfris -filetype=obj -o test_xdp_noinline.o # pahole -J test_xdp_noinline.o
Now loading into kernel and dumping the map via bpftool:
# ip -force link set dev lo xdp obj test_xdp_noinline.o sec xdp-test # ip a 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 xdpgeneric/id:227 qdisc noqueue state UNKNOWN group default qlen 1000 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever [...] # bpftool prog show id 227 227: xdp tag a85e060c275c5616 gpl loaded_at 2018-07-17T14:41:29+0000 uid 0 xlated 8152B not jited memlock 12288B map_ids 381,385,386,382,384,383 # bpftool map dump id 386 [{ "key": 0, "value": { "": { "value": 0, "ifindex": 0, "mac": [] } } },{ "key": 1, "value": { "": { "value": 0, "ifindex": 0, "mac": [] } } },{ [...]
Lookup, update, delete, and ‘get next key’ operations on the map for specific keys can be performed through bpftool as well.
BPF sysctls¶
The Linux kernel provides few sysctls that are BPF related and covered in this section.
/proc/sys/net/core/bpf_jit_enable: Enables or disables the BPF JIT compiler.Value Description 0 Disable the JIT and use only interpreter (kernel’s default value) 1 Enable the JIT compiler 2 Enable the JIT and emit debugging traces to the kernel log As described in subsequent sections,
bpf_jit_disasmtool can be used to process debugging traces when the JIT compiler is set to debugging mode (option2)./proc/sys/net/core/bpf_jit_harden: Enables or disables BPF JIT hardening. Note that enabling hardening trades off performance, but can mitigate JIT spraying by blinding out the BPF program’s immediate values. For programs processed through the interpreter, blinding of immediate values is not needed / performed.Value Description 0 Disable JIT hardening (kernel’s default value) 1 Enable JIT hardening for unprivileged users only 2 Enable JIT hardening for all users /proc/sys/net/core/bpf_jit_kallsyms: Enables or disables export of JITed programs as kernel symbols to/proc/kallsymsso that they can be used together withperftooling as well as making these addresses aware to the kernel for stack unwinding, for example, used in dumping stack traces. The symbol names contain the BPF program tag (bpf_prog_<tag>). Ifbpf_jit_hardenis enabled, then this feature is disabled.Value Description 0 Disable JIT kallsyms export (kernel’s default value) 1 Enable JIT kallsyms export for privileged users only /proc/sys/kernel/unprivileged_bpf_disabled: Enables or disable unprivileged use of thebpf(2)system call. The Linux kernel has unprivileged use ofbpf(2)enabled by default, but once the switch is flipped, unprivileged use will be permanently disabled until the next reboot. This sysctl knob is a one-time switch, meaning if once set, then neither an application nor an admin can reset the value anymore. This knob does not affect any cBPF programs such as seccomp or traditional socket filters that do not use thebpf(2)system call for loading the program into the kernel.Value Description 0 Unprivileged use of bpf syscall enabled (kernel’s default value) 1 Unprivileged use of bpf syscall disabled
Kernel Testing¶
The Linux kernel ships a BPF selftest suite, which can be found in the kernel
source tree under tools/testing/selftests/bpf/.
$ cd tools/testing/selftests/bpf/
$ make
# make run_tests
The test suite contains test cases against the BPF verifier, program tags, various tests against the BPF map interface and map types. It contains various runtime tests from C code for checking LLVM back end, and eBPF as well as cBPF asm code that is run in the kernel for testing the interpreter and JITs.
JIT Debugging¶
For JIT developers performing audits or writing extensions, each compile run can output the generated JIT image into the kernel log through:
# echo 2 > /proc/sys/net/core/bpf_jit_enable
Whenever a new BPF program is loaded, the JIT compiler will dump the output,
which can then be inspected with dmesg, for example:
[ 3389.935842] flen=6 proglen=70 pass=3 image=ffffffffa0069c8f from=tcpdump pid=20583
[ 3389.935847] JIT code: 00000000: 55 48 89 e5 48 83 ec 60 48 89 5d f8 44 8b 4f 68
[ 3389.935849] JIT code: 00000010: 44 2b 4f 6c 4c 8b 87 d8 00 00 00 be 0c 00 00 00
[ 3389.935850] JIT code: 00000020: e8 1d 94 ff e0 3d 00 08 00 00 75 16 be 17 00 00
[ 3389.935851] JIT code: 00000030: 00 e8 28 94 ff e0 83 f8 01 75 07 b8 ff ff 00 00
[ 3389.935852] JIT code: 00000040: eb 02 31 c0 c9 c3
flen is the length of the BPF program (here, 6 BPF instructions), and proglen
tells the number of bytes generated by the JIT for the opcode image (here, 70 bytes
in size). pass means that the image was generated in 3 compiler passes, for
example, x86_64 can have various optimization passes to further reduce the image
size when possible. image contains the address of the generated JIT image, from
and pid the user space application name and PID respectively, which triggered the
compilation process. The dump output for eBPF and cBPF JITs is the same format.
In the kernel tree under tools/bpf/, there is a tool called bpf_jit_disasm. It
reads out the latest dump and prints the disassembly for further inspection:
# ./bpf_jit_disasm
70 bytes emitted from JIT compiler (pass:3, flen:6)
ffffffffa0069c8f + <x>:
0: push %rbp
1: mov %rsp,%rbp
4: sub $0x60,%rsp
8: mov %rbx,-0x8(%rbp)
c: mov 0x68(%rdi),%r9d
10: sub 0x6c(%rdi),%r9d
14: mov 0xd8(%rdi),%r8
1b: mov $0xc,%esi
20: callq 0xffffffffe0ff9442
25: cmp $0x800,%eax
2a: jne 0x0000000000000042
2c: mov $0x17,%esi
31: callq 0xffffffffe0ff945e
36: cmp $0x1,%eax
39: jne 0x0000000000000042
3b: mov $0xffff,%eax
40: jmp 0x0000000000000044
42: xor %eax,%eax
44: leaveq
45: retq
Alternatively, the tool can also dump related opcodes along with the disassembly.
# ./bpf_jit_disasm -o
70 bytes emitted from JIT compiler (pass:3, flen:6)
ffffffffa0069c8f + <x>:
0: push %rbp
55
1: mov %rsp,%rbp
48 89 e5
4: sub $0x60,%rsp
48 83 ec 60
8: mov %rbx,-0x8(%rbp)
48 89 5d f8
c: mov 0x68(%rdi),%r9d
44 8b 4f 68
10: sub 0x6c(%rdi),%r9d
44 2b 4f 6c
14: mov 0xd8(%rdi),%r8
4c 8b 87 d8 00 00 00
1b: mov $0xc,%esi
be 0c 00 00 00
20: callq 0xffffffffe0ff9442
e8 1d 94 ff e0
25: cmp $0x800,%eax
3d 00 08 00 00
2a: jne 0x0000000000000042
75 16
2c: mov $0x17,%esi
be 17 00 00 00
31: callq 0xffffffffe0ff945e
e8 28 94 ff e0
36: cmp $0x1,%eax
83 f8 01
39: jne 0x0000000000000042
75 07
3b: mov $0xffff,%eax
b8 ff ff 00 00
40: jmp 0x0000000000000044
eb 02
42: xor %eax,%eax
31 c0
44: leaveq
c9
45: retq
c3
More recently, bpftool adapted the same feature of dumping the BPF JIT
image based on a given BPF program ID already loaded in the system (see
bpftool section).
For performance analysis of JITed BPF programs, perf can be used as
usual. As a prerequisite, JITed programs need to be exported through kallsyms
infrastructure.
# echo 1 > /proc/sys/net/core/bpf_jit_enable
# echo 1 > /proc/sys/net/core/bpf_jit_kallsyms
Enabling or disabling bpf_jit_kallsyms does not require a reload of the
related BPF programs. Next, a small workflow example is provided for profiling
BPF programs. A crafted tc BPF program is used for demonstration purposes,
where perf records a failed allocation inside bpf_clone_redirect() helper.
Due to the use of direct write, bpf_try_make_head_writable() failed, which
would then release the cloned skb again and return with an error message.
perf thus records all kfree_skb events.
# tc qdisc add dev em1 clsact
# tc filter add dev em1 ingress bpf da obj prog.o sec main
# tc filter show dev em1 ingress
filter protocol all pref 49152 bpf
filter protocol all pref 49152 bpf handle 0x1 prog.o:[main] direct-action id 1 tag 8227addf251b7543
# cat /proc/kallsyms
[...]
ffffffffc00349e0 t fjes_hw_init_command_registers [fjes]
ffffffffc003e2e0 d __tracepoint_fjes_hw_stop_debug_err [fjes]
ffffffffc0036190 t fjes_hw_epbuf_tx_pkt_send [fjes]
ffffffffc004b000 t bpf_prog_8227addf251b7543
# perf record -a -g -e skb:kfree_skb sleep 60
# perf script --kallsyms=/proc/kallsyms
[...]
ksoftirqd/0 6 [000] 1004.578402: skb:kfree_skb: skbaddr=0xffff9d4161f20a00 protocol=2048 location=0xffffffffc004b52c
7fffb8745961 bpf_clone_redirect (/lib/modules/4.10.0+/build/vmlinux)
7fffc004e52c bpf_prog_8227addf251b7543 (/lib/modules/4.10.0+/build/vmlinux)
7fffc05b6283 cls_bpf_classify (/lib/modules/4.10.0+/build/vmlinux)
7fffb875957a tc_classify (/lib/modules/4.10.0+/build/vmlinux)
7fffb8729840 __netif_receive_skb_core (/lib/modules/4.10.0+/build/vmlinux)
7fffb8729e38 __netif_receive_skb (/lib/modules/4.10.0+/build/vmlinux)
7fffb872ae05 process_backlog (/lib/modules/4.10.0+/build/vmlinux)
7fffb872a43e net_rx_action (/lib/modules/4.10.0+/build/vmlinux)
7fffb886176c __do_softirq (/lib/modules/4.10.0+/build/vmlinux)
7fffb80ac5b9 run_ksoftirqd (/lib/modules/4.10.0+/build/vmlinux)
7fffb80ca7fa smpboot_thread_fn (/lib/modules/4.10.0+/build/vmlinux)
7fffb80c6831 kthread (/lib/modules/4.10.0+/build/vmlinux)
7fffb885e09c ret_from_fork (/lib/modules/4.10.0+/build/vmlinux)
The stack trace recorded by perf will then show the bpf_prog_8227addf251b7543()
symbol as part of the call trace, meaning that the BPF program with the
tag 8227addf251b7543 was related to the kfree_skb event, and
such program was attached to netdevice em1 on the ingress hook as
shown by tc.
Introspection¶
The Linux kernel provides various tracepoints around BPF and XDP which can be used for additional introspection, for example, to trace interactions of user space programs with the bpf system call.
Tracepoints for BPF:
# perf list | grep bpf:
bpf:bpf_map_create [Tracepoint event]
bpf:bpf_map_delete_elem [Tracepoint event]
bpf:bpf_map_lookup_elem [Tracepoint event]
bpf:bpf_map_next_key [Tracepoint event]
bpf:bpf_map_update_elem [Tracepoint event]
bpf:bpf_obj_get_map [Tracepoint event]
bpf:bpf_obj_get_prog [Tracepoint event]
bpf:bpf_obj_pin_map [Tracepoint event]
bpf:bpf_obj_pin_prog [Tracepoint event]
bpf:bpf_prog_get_type [Tracepoint event]
bpf:bpf_prog_load [Tracepoint event]
bpf:bpf_prog_put_rcu [Tracepoint event]
Example usage with perf (alternatively to sleep example used here,
a specific application like tc could be used here instead, of course):
# perf record -a -e bpf:* sleep 10
# perf script
sock_example 6197 [005] 283.980322: bpf:bpf_map_create: map type=ARRAY ufd=4 key=4 val=8 max=256 flags=0
sock_example 6197 [005] 283.980721: bpf:bpf_prog_load: prog=a5ea8fa30ea6849c type=SOCKET_FILTER ufd=5
sock_example 6197 [005] 283.988423: bpf:bpf_prog_get_type: prog=a5ea8fa30ea6849c type=SOCKET_FILTER
sock_example 6197 [005] 283.988443: bpf:bpf_map_lookup_elem: map type=ARRAY ufd=4 key=[06 00 00 00] val=[00 00 00 00 00 00 00 00]
[...]
sock_example 6197 [005] 288.990868: bpf:bpf_map_lookup_elem: map type=ARRAY ufd=4 key=[01 00 00 00] val=[14 00 00 00 00 00 00 00]
swapper 0 [005] 289.338243: bpf:bpf_prog_put_rcu: prog=a5ea8fa30ea6849c type=SOCKET_FILTER
For the BPF programs, their individual program tag is displayed.
For debugging, XDP also has a tracepoint that is triggered when exceptions are raised:
# perf list | grep xdp:
xdp:xdp_exception [Tracepoint event]
Exceptions are triggered in the following scenarios:
- The BPF program returned an invalid / unknown XDP action code.
- The BPF program returned with
XDP_ABORTEDindicating a non-graceful exit. - The BPF program returned with
XDP_TX, but there was an error on transmit, for example, due to the port not being up, due to the transmit ring being full, due to allocation failures, etc.
Both tracepoint classes can also be inspected with a BPF program itself
attached to one or more tracepoints, collecting further information
in a map or punting such events to a user space collector through the
bpf_perf_event_output() helper, for example.
Miscellaneous¶
BPF programs and maps are memory accounted against RLIMIT_MEMLOCK similar
to perf. The currently available size in unit of system pages which may be
locked into memory can be inspected through ulimit -l. The setrlimit system
call man page provides further details.
The default limit is usually insufficient to load more complex programs or
larger BPF maps, so that the BPF system call will return with errno
of EPERM. In such situations a workaround with ulimit -l unlimited or
with a sufficiently large limit could be performed. The RLIMIT_MEMLOCK is
mainly enforcing limits for unprivileged users. Depending on the setup,
setting a higher limit for privileged users is often acceptable.
Program Types¶
At the time of this writing, there are eighteen different BPF program types available, two of the main types for networking are further explained in below subsections, namely XDP BPF programs as well as tc BPF programs. Extensive usage examples for the two program types for LLVM, iproute2 or other tools are spread throughout the toolchain section and not covered here. Instead, this section focuses on their architecture, concepts and use cases.
XDP¶
XDP stands for eXpress Data Path and provides a framework for BPF that enables high-performance programmable packet processing in the Linux kernel. It runs the BPF program at the earliest possible point in software, namely at the moment the network driver receives the packet.
At this point in the fast-path the driver just picked up the packet from its
receive rings, without having done any expensive operations such as allocating
an skb for pushing the packet further up the networking stack, without
having pushed the packet into the GRO engine, etc. Thus, the XDP BPF program
is executed at the earliest point when it becomes available to the CPU for
processing.
XDP works in concert with the Linux kernel and its infrastructure, meaning the kernel is not bypassed as in various networking frameworks that operate in user space only. Keeping the packet in kernel space has several major advantages:
- XDP is able to reuse all the upstream developed kernel networking drivers, user space tooling, or even other available in-kernel infrastructure such as routing tables, sockets, etc in BPF helper calls itself.
- Residing in kernel space, XDP has the same security model as the rest of the kernel for accessing hardware.
- There is no need for crossing kernel / user space boundaries since the processed packet already resides in the kernel and can therefore flexibly forward packets into other in-kernel entities like namespaces used by containers or the kernel’s networking stack itself. This is particularly relevant in times of Meltdown and Spectre.
- Punting packets from XDP to the kernel’s robust, widely used and efficient TCP/IP stack is trivially possible, allows for full reuse and does not require maintaining a separate TCP/IP stack as with user space frameworks.
- The use of BPF allows for full programmability, keeping a stable ABI with the same ‘never-break-user-space’ guarantees as with the kernel’s system call ABI and compared to modules it also provides safety measures thanks to the BPF verifier that ensures the stability of the kernel’s operation.
- XDP trivially allows for atomically swapping programs during runtime without any network traffic interruption or even kernel / system reboot.
- XDP allows for flexible structuring of workloads integrated into the kernel. For example, it can operate in “busy polling” or “interrupt driven” mode. Explicitly dedicating CPUs to XDP is not required. There are no special hardware requirements and it does not rely on hugepages.
- XDP does not require any third party kernel modules or licensing. It is a long-term architectural solution, a core part of the Linux kernel, and developed by the kernel community.
- XDP is already enabled and shipped everywhere with major distributions running a kernel equivalent to 4.8 or higher and supports most major 10G or higher networking drivers.
As a framework for running BPF in the driver, XDP additionally ensures that
packets are laid out linearly and fit into a single DMA’ed page which is
readable and writable by the BPF program. XDP also ensures that additional
headroom of 256 bytes is available to the program for implementing custom
encapsulation headers with the help of the bpf_xdp_adjust_head() BPF helper
or adding custom metadata in front of the packet through bpf_xdp_adjust_meta().
The framework contains XDP action codes further described in the section below which a BPF program can return in order to instruct the driver how to proceed with the packet, and it enables the possibility to atomically replace BPF programs running at the XDP layer. XDP is tailored for high-performance by design. BPF allows to access the packet data through ‘direct packet access’ which means that the program holds data pointers directly in registers, loads the content into registers, respectively writes from there into the packet.
The packet representation in XDP that is passed to the BPF program as the BPF context looks as follows:
struct xdp_buff {
void *data;
void *data_end;
void *data_meta;
void *data_hard_start;
struct xdp_rxq_info *rxq;
};
data points to the start of the packet data in the page, and as the
name suggests, data_end points to the end of the packet data. Since XDP
allows for a headroom, data_hard_start points to the maximum possible
headroom start in the page, meaning, when the packet should be encapsulated,
then data is moved closer towards data_hard_start via bpf_xdp_adjust_head().
The same BPF helper function also allows for decapsulation in which case
data is moved further away from data_hard_start.
data_meta initially points to the same location as data but
bpf_xdp_adjust_meta() is able to move the pointer towards data_hard_start
as well in order to provide room for custom metadata which is invisible to
the normal kernel networking stack but can be read by tc BPF programs since
it is transferred from XDP to the skb. Vice versa, it can remove or reduce
the size of the custom metadata through the same BPF helper function by
moving data_meta away from data_hard_start again. data_meta can
also be used solely for passing state between tail calls similarly to the
skb->cb[] control block case that is accessible in tc BPF programs.
This gives the following relation respectively invariant for the struct xdp_buff
packet pointers: data_hard_start <= data_meta <= data < data_end.
The rxq field points to some additional per receive queue metadata which
is populated at ring setup time (not at XDP runtime):
struct xdp_rxq_info {
struct net_device *dev;
u32 queue_index;
u32 reg_state;
} ____cacheline_aligned;
The BPF program can retrieve queue_index as well as additional data
from the netdevice itself such as ifindex, etc.
BPF program return codes
After running the XDP BPF program, a verdict is returned from the program in
order to tell the driver how to process the packet next. In the linux/bpf.h
system header file all available return verdicts are enumerated:
enum xdp_action {
XDP_ABORTED = 0,
XDP_DROP,
XDP_PASS,
XDP_TX,
XDP_REDIRECT,
};
XDP_DROP as the name suggests will drop the packet right at the driver
level without wasting any further resources. This is in particular useful
for BPF programs implementing DDoS mitigation mechanisms or firewalling in
general. The XDP_PASS return code means that the packet is allowed to
be passed up to the kernel’s networking stack. Meaning, the current CPU
that was processing this packet now allocates a skb, populates it, and
passes it onwards into the GRO engine. This would be equivalent to the
default packet handling behavior without XDP. With XDP_TX the BPF program
has an efficient option to transmit the network packet out of the same NIC it
just arrived on again. This is typically useful when few nodes are implementing,
for example, firewalling with subsequent load balancing in a cluster and
thus act as a hairpinned load balancer pushing the incoming packets back
into the switch after rewriting them in XDP BPF. XDP_REDIRECT is similar
to XDP_TX in that it is able to transmit the XDP packet, but through
another NIC. Another option for the XDP_REDIRECT case is to redirect
into a BPF cpumap, meaning, the CPUs serving XDP on the NIC’s receive queues
can continue to do so and push the packet for processing the upper kernel
stack to a remote CPU. This is similar to XDP_PASS, but with the ability
that the XDP BPF program can keep serving the incoming high load as opposed
to temporarily spend work on the current packet for pushing into upper
layers. Last but not least, XDP_ABORTED which serves denoting an exception
like state from the program and has the same behavior as XDP_DROP only
that XDP_ABORTED passes the trace_xdp_exception tracepoint which
can be additionally monitored to detect misbehavior.
Use cases for XDP
Some of the main use cases for XDP are presented in this subsection. The list is non-exhaustive and given the programmability and efficiency XDP and BPF enables, it can easily be adapted to solve very specific use cases.
DDoS mitigation, firewalling
One of the basic XDP BPF features is to tell the driver to drop a packet with
XDP_DROPat this early stage which allows for any kind of efficient network policy enforcement with having an extremely low per-packet cost. This is ideal in situations when needing to cope with any sort of DDoS attacks, but also more general allows to implement any sort of firewalling policies with close to no overhead in BPF e.g. in either case as stand alone appliance (e.g. scrubbing ‘clean’ traffic throughXDP_TX) or widely deployed on nodes protecting end hosts themselves (viaXDP_PASSor cpumapXDP_REDIRECTfor good traffic). Offloaded XDP takes this even one step further by moving the already small per-packet cost entirely into the NIC with processing at line-rate.
Forwarding and load-balancing
Another major use case of XDP is packet forwarding and load-balancing through either
XDP_TXorXDP_REDIRECTactions. The packet can be arbitrarily mangled by the BPF program running in the XDP layer, even BPF helper functions are available for increasing or decreasing the packet’s headroom in order to arbitrarily encapsulate respectively decapsulate the packet before sending it out again. WithXDP_TXhairpinned load-balancers can be implemented that push the packet out of the same networking device it originally arrived on, or with theXDP_REDIRECTaction it can be forwarded to another NIC for transmission. The latter return code can also be used in combination with BPF’s cpumap to load-balance packets for passing up the local stack, but on remote, non-XDP processing CPUs.
Pre-stack filtering / processing
Besides policy enforcement, XDP can also be used for hardening the kernel’s networking stack with the help of
XDP_DROPcase, meaning, it can drop irrelevant packets for a local node right at the earliest possible point before the networking stack sees them e.g. given we know that a node only serves TCP traffic, any UDP, SCTP or other L4 traffic can be dropped right away. This has the advantage that packets do not need to traverse various entities like GRO engine, the kernel’s flow dissector and others before it can be determined to drop them and thus this allows for reducing the kernel’s attack surface. Thanks to XDP’s early processing stage, this effectively ‘pretends’ to the kernel’s networking stack that these packets have never been seen by the networking device. Additionally, if a potential bug in the stack’s receive path got uncovered and would cause a ‘ping of death’ like scenario, XDP can be utilized to drop such packets right away without having to reboot the kernel or restart any services. Due to the ability to atomically swap such programs to enforce a drop of bad packets, no network traffic is even interrupted on a host.Another use case for pre-stack processing is that given the kernel has not yet allocated an
skbfor the packet, the BPF program is free to modify the packet and, again, have it ‘pretend’ to the stack that it was received by the networking device this way. This allows for cases such as having custom packet mangling and encapsulation protocols where the packet can be decapsulated prior to entering GRO aggregation in which GRO otherwise would not be able to perform any sort of aggregation due to not being aware of the custom protocol. XDP also allows to push metadata (non-packet data) in front of the packet. This is ‘invisible’ to the normal kernel stack, can be GRO aggregated (for matching metadata) and later on processed in coordination with a tc ingress BPF program where it has the context of askbavailable for e.g. setting various skb fields.
Flow sampling, monitoring
XDP can also be used for cases such as packet monitoring, sampling or any other network analytics, for example, as part of an intermediate node in the path or on end hosts in combination also with prior mentioned use cases. For complex packet analysis, XDP provides a facility to efficiently push network packets (truncated or with full payload) and custom metadata into a fast lockless per CPU memory mapped ring buffer provided from the Linux perf infrastructure to an user space application. This also allows for cases where only a flow’s initial data can be analyzed and once determined as good traffic having the monitoring bypassed. Thanks to the flexibility brought by BPF, this allows for implementing any sort of custom monitoring or sampling.
One example of XDP BPF production usage is Facebook’s SHIV and Droplet infrastructure which implement their L4 load-balancing and DDoS countermeasures. Migrating their production infrastructure away from netfilter’s IPVS (IP Virtual Server) over to XDP BPF allowed for a 10x speedup compared to their previous IPVS setup. This was first presented at the netdev 2.1 conference:
- Slides: https://www.netdevconf.org/2.1/slides/apr6/zhou-netdev-xdp-2017.pdf
- Video: https://youtu.be/YEU2ClcGqts
Another example is the integration of XDP into Cloudflare’s DDoS mitigation
pipeline, which originally was using cBPF instead of eBPF for attack signature
matching through iptables’ xt_bpf module. Due to use of iptables this
caused severe performance problems under attack where a user space bypass
solution was deemed necessary but came with drawbacks as well such as needing
to busy poll the NIC and expensive packet re-injection into the kernel’s stack.
The migration over to eBPF and XDP combined best of both worlds by having
high-performance programmable packet processing directly inside the kernel:
- Slides: https://www.netdevconf.org/2.1/slides/apr6/bertin_Netdev-XDP.pdf
- Video: https://youtu.be/7OuOukmuivg
XDP operation modes
XDP has three operation modes where ‘native’ XDP is the default mode. When talked about XDP this mode is typically implied.
Native XDP
This is the default mode where the XDP BPF program is run directly out of the networking driver’s early receive path. Most widespread used NICs for 10G and higher support native XDP already.
Offloaded XDP
In the offloaded XDP mode the XDP BPF program is directly offloaded into the NIC instead of being executed on the host CPU. Thus, the already extremely low per-packet cost is pushed off the host CPU entirely and executed on the NIC, providing even higher performance than running in native XDP. This offload is typically implemented by SmartNICs containing multi-threaded, multicore flow processors where a in-kernel JIT compiler translates BPF into native instructions for the latter. Drivers supporting offloaded XDP usually also support native XDP for cases where some BPF helpers may not yet or only be available for the native mode.
Generic XDP
For drivers not implementing native or offloaded XDP yet, the kernel provides an option for generic XDP which does not require any driver changes since run at a much later point out of the networking stack. This setting is primarily targeted at developers who want to write and test programs against the kernel’s XDP API, and will not operate at the performance rate of the native or offloaded modes. For XDP usage in a production environment either the native or offloaded mode is better suited and the recommended way to run XDP.
Driver support
Since BPF and XDP is evolving quickly in terms of feature and driver support, the following lists native and offloaded XDP drivers as of kernel 4.17.
Drivers supporting native XDP
- Broadcom
- bnxt
- Cavium
- thunderx
- Intel
- ixgbe
- ixgbevf
- i40e
- Mellanox
- mlx4
- mlx5
- Netronome
- nfp
- Others
- tun
- virtio_net
- Qlogic
- qede
- Solarflare
- sfc [1]
Drivers supporting offloaded XDP
- Netronome
- nfp [2]
Note that examples for writing and loading XDP programs are included in the toolchain section under the respective tools.
| [1] | XDP for sfc available via out of tree driver as of kernel 4.17, but will be upstreamed soon. |
| [2] | (1, 2) Some BPF helper functions such as retrieving the current CPU number will not be available in an offloaded setting. |
tc (traffic control)¶
Aside from other program types such as XDP, BPF can also be used out of the kernel’s tc (traffic control) layer in the networking data path. On a high-level there are three major differences when comparing XDP BPF programs to tc BPF ones:
The BPF input context is a
sk_buffnot axdp_buff. When the kernel’s networking stack receives a packet, after the XDP layer, it allocates a buffer and parses the packet to store metadata about the packet. This representation is known as thesk_buff. This structure is then exposed in the BPF input context so that BPF programs from the tc ingress layer can use the metadata that the stack extracts from the packet. This can be useful, but comes with an associated cost of the stack performing this allocation and metadata extraction, and handling the packet until it hits the tc hook. By definition, thexdp_buffdoesn’t have access to this metadata because the XDP hook is called before this work is done. This is a significant contributor to the performance difference between the XDP and tc hooks.Therefore, BPF programs attached to the tc BPF hook can, for instance, read or write the skb’s
mark,pkt_type,protocol,priority,queue_mapping,napi_id,cb[]array,hash,tc_classidortc_index, vlan metadata, the XDP transferred custom metadata and various other information. All members of thestruct __sk_buffBPF context used in tc BPF are defined in thelinux/bpf.hsystem header.Generally, the
sk_buffis of a completely different nature thanxdp_buffwhere both come with advantages and disadvantages. For example, thesk_buffcase has the advantage that it is rather straight forward to mangle its associated metadata, however, it also contains a lot of protocol specific information (e.g. GSO related state) which makes it difficult to simply switch protocols by solely rewriting the packet data. This is due to the stack processing the packet based on the metadata rather than having the cost of accessing the packet contents each time. Thus, additional conversion is required from BPF helper functions taking care thatsk_buffinternals are properly converted as well. Thexdp_buffcase however does not face such issues since it comes at such an early stage where the kernel has not even allocated ansk_buffyet, thus packet rewrites of any kind can be realized trivially. However, thexdp_buffcase has the disadvantage thatsk_buffmetadata is not available for mangling at this stage. The latter is overcome by passing custom metadata from XDP BPF to tc BPF, though. In this way, the limitations of each program type can be overcome by operating complementary programs of both types as the use case requires.
Compared to XDP, tc BPF programs can be triggered out of ingress and also egress points in the networking data path as opposed to ingress only in the case of XDP.
The two hook points
sch_handle_ingress()andsch_handle_egress()in the kernel are triggered out of__netif_receive_skb_core()and__dev_queue_xmit(), respectively. The latter two are the main receive and transmit functions in the data path that, setting XDP aside, are triggered for every network packet going in or coming out of the node allowing for full visibility for tc BPF programs at these hook points.
The tc BPF programs do not require any driver changes since they are run at hook points in generic layers in the networking stack. Therefore, they can be attached to any type of networking device.
While this provides flexibility, it also trades off performance compared to running at the native XDP layer. However, tc BPF programs still come at the earliest point in the generic kernel’s networking data path after GRO has been run but before any protocol processing, traditional iptables firewalling such as iptables PREROUTING or nftables ingress hooks or other packet processing takes place. Likewise on egress, tc BPF programs execute at the latest point before handing the packet to the driver itself for transmission, meaning after traditional iptables firewalling hooks like iptables POSTROUTING, but still before handing the packet to the kernel’s GSO engine.
One exception which does require driver changes however are offloaded tc BPF programs, typically provided by SmartNICs in a similar way as offloaded XDP just with differing set of features due to the differences in the BPF input context, helper functions and verdict codes.
BPF programs run in the tc layer are run from the cls_bpf classifier.
While the tc terminology describes the BPF attachment point as a “classifier”,
this is a bit misleading since it under-represents what cls_bpf is
capable of. That is to say, a fully programmable packet processor being able
not only to read the skb metadata and packet data, but to also arbitrarily
mangle both, and terminate the tc processing with an action verdict. cls_bpf
can thus be regarded as a self-contained entity that manages and executes tc
BPF programs.
cls_bpf can hold one or more tc BPF programs. In the case where Cilium
deploys cls_bpf programs, it attaches only a single program for a given hook
in direct-action mode. Typically, in the traditional tc scheme, there is a
split between classifier and action modules, where the classifier has one
or more actions attached to it that are triggered once the classifier has a
match. In the modern world for using tc in the software data path this model
does not scale well for complex packet processing. Given tc BPF programs
attached to cls_bpf are fully self-contained, they effectively fuse the
parsing and action process together into a single unit. Thanks to cls_bpf’s
direct-action mode, it will just return the tc action verdict and
terminate the processing pipeline immediately. This allows for implementing
scalable programmable packet processing in the networking data path by avoiding
linear iteration of actions. cls_bpf is the only such “classifier” module
in the tc layer capable of such a fast-path.
Like XDP BPF programs, tc BPF programs can be atomically updated at runtime
via cls_bpf without interrupting any network traffic or having to restart
services.
Both the tc ingress and the egress hook where cls_bpf itself can be
attached to is managed by a pseudo qdisc called sch_clsact. This is a
drop-in replacement and proper superset of the ingress qdisc since it
is able to manage both, ingress and egress tc hooks. For tc’s egress hook
in __dev_queue_xmit() it is important to stress that it is not executed
under the kernel’s qdisc root lock. Thus, both tc ingress and egress hooks
are executed in a lockless manner in the fast-path. In either case, preemption
is disabled and execution happens under RCU read side.
Typically on egress there are qdiscs attached to netdevices such as sch_mq,
sch_fq, sch_fq_codel or sch_htb where some of them are classful
qdiscs that contain subclasses and thus require a packet classification
mechanism to determine a verdict where to demux the packet. This is handled
by a call to tcf_classify() which calls into tc classifiers if present.
cls_bpf can also be attached and used in such cases. Such operation usually
happens under the qdisc root lock and can be subject to lock contention. The
sch_clsact qdisc’s egress hook comes at a much earlier point however which
does not fall under that and operates completely independent from conventional
egress qdiscs. Thus for cases like sch_htb the sch_clsact qdisc could
perform the heavy lifting packet classification through tc BPF outside of the
qdisc root lock, setting the skb->mark or skb->priority from there such
that sch_htb only requires a flat mapping without expensive packet
classification under the root lock thus reducing contention.
Offloaded tc BPF programs are supported for the case of sch_clsact in
combination with cls_bpf where the prior loaded BPF program was JITed
from a SmartNIC driver to be run natively on the NIC. Only cls_bpf
programs operating in direct-action mode are supported to be offloaded.
cls_bpf only supports offloading a single program and cannot offload
multiple programs. Furthermore only the ingress hook supports offloading
BPF programs.
One cls_bpf instance is able to hold multiple tc BPF programs internally.
If this is the case, then the TC_ACT_UNSPEC program return code will
continue execution with the next tc BPF program in that list. However, this
has the drawback that several programs would need to parse the packet over
and over again resulting in degraded performance.
BPF program return codes
Both the tc ingress and egress hook share the same action return verdicts
that tc BPF programs can use. They are defined in the linux/pkt_cls.h
system header:
#define TC_ACT_UNSPEC (-1)
#define TC_ACT_OK 0
#define TC_ACT_SHOT 2
#define TC_ACT_STOLEN 4
#define TC_ACT_REDIRECT 7
There are a few more action TC_ACT_* verdicts available in the system
header file which are also used in the two hooks. However, they share the
same semantics with the ones above. Meaning, from a tc BPF perspective,
TC_ACT_OK and TC_ACT_RECLASSIFY have the same semantics, as well as
the three TC_ACT_STOLEN, TC_ACT_QUEUED and TC_ACT_TRAP opcodes.
Therefore, for these cases we only describe TC_ACT_OK and the TC_ACT_STOLEN
opcode for the two groups.
Starting out with TC_ACT_UNSPEC. It has the meaning of “unspecified action”
and is used in three cases, i) when an offloaded tc BPF program is attached
and the tc ingress hook is run where the cls_bpf representation for the
offloaded program will return TC_ACT_UNSPEC, ii) in order to continue
with the next tc BPF program in cls_bpf for the multi-program case. The
latter also works in combination with offloaded tc BPF programs from point i)
where the TC_ACT_UNSPEC from there continues with a next tc BPF program
solely running in non-offloaded case. Last but not least, iii) TC_ACT_UNSPEC
is also used for the single program case to simply tell the kernel to continue
with the skb without additional side-effects. TC_ACT_UNSPEC is very
similar to the TC_ACT_OK action code in the sense that both pass the
skb onwards either to upper layers of the stack on ingress or down to
the networking device driver for transmission on egress, respectively. The
only difference to TC_ACT_OK is that TC_ACT_OK sets skb->tc_index
based on the classid the tc BPF program set. The latter is set out of the
tc BPF program itself through skb->tc_classid from the BPF context.
TC_ACT_SHOT instructs the kernel to drop the packet, meaning, upper
layers of the networking stack will never see the skb on ingress and
similarly the packet will never be submitted for transmission on egress.
TC_ACT_SHOT and TC_ACT_STOLEN are both similar in nature with few
differences: TC_ACT_SHOT will indicate to the kernel that the skb
was released through kfree_skb() and return NET_XMIT_DROP to the
callers for immediate feedback, whereas TC_ACT_STOLEN will release
the skb through consume_skb() and pretend to upper layers that
the transmission was successful through NET_XMIT_SUCCESS. The perf’s
drop monitor which records traces of kfree_skb() will therefore
also not see any drop indications from TC_ACT_STOLEN since its
semantics are such that the skb has been “consumed” or queued but
certainly not “dropped”.
Last but not least the TC_ACT_REDIRECT action which is available for
tc BPF programs as well. This allows to redirect the skb to the same
or another’s device ingress or egress path together with the bpf_redirect()
helper. Being able to inject the packet into another device’s ingress or
egress direction allows for full flexibility in packet forwarding with
BPF. There are no requirements on the target networking device other than
being a networking device itself, there is no need to run another instance
of cls_bpf on the target device or other such restrictions.
tc BPF FAQ
This section contains a few miscellaneous question and answer pairs related to tc BPF programs that are asked from time to time.
- Question: What about
act_bpfas a tc action module, is it still relevant? - Answer: Not really. Although
cls_bpfandact_bpfshare the same functionality for tc BPF programs,cls_bpfis more flexible since it is a proper superset ofact_bpf. The way tc works is that tc actions need to be attached to tc classifiers. In order to achieve the same flexibility ascls_bpf,act_bpfwould need to be attached to thecls_matchallclassifier. As the name says, this will match on every packet in order to pass them through for attached tc action processing. Foract_bpf, this is will result in less efficient packet processing than usingcls_bpfindirect-actionmode directly. Ifact_bpfis used in a setting with other classifiers thancls_bpforcls_matchallthen this will perform even worse due to the nature of operation of tc classifiers. Meaning, if classifier A has a mismatch, then the packet is passed to classifier B, reparsing the packet, etc, thus in the typical case there will be linear processing where the packet would need to traverse N classifiers in the worst case to find a match and executeact_bpfon that. Therefore,act_bpfhas never been largely relevant. Additionally,act_bpfdoes not provide a tc offloading interface either compared tocls_bpf.
- Question: Is it recommended to use
cls_bpfnot indirect-actionmode? - Answer: No. The answer is similar to the one above in that this is otherwise
unable to scale for more complex processing. tc BPF can already do everything needed
by itself in an efficient manner and thus there is no need for anything other than
direct-actionmode.
- Question: Is there any performance difference in offloaded
cls_bpfand offloaded XDP? - Answer: No. Both are JITed through the same compiler in the kernel which handles the offloading to the SmartNIC and the loading mechanism for both is very similar as well. Thus, the BPF program gets translated into the same target instruction set in order to be able to run on the NIC natively. The two tc BPF and XDP BPF program types have a differing set of features, so depending on the use case one might be picked over the other due to availability of certain helper functions in the offload case, for example.
Use cases for tc BPF
Some of the main use cases for tc BPF programs are presented in this subsection. Also here, the list is non-exhaustive and given the programmability and efficiency of tc BPF, it can easily be tailored and integrated into orchestration systems in order to solve very specific use cases. While some use cases with XDP may overlap, tc BPF and XDP BPF are mostly complementary to each other and both can also be used at the same time or one over the other depending which is most suitable for a given problem to solve.
Policy enforcement for containers
One application which tc BPF programs are suitable for is to implement policy enforcement, custom firewalling or similar security measures for containers or pods, respectively. In the conventional case, container isolation is implemented through network namespaces with veth networking devices connecting the host’s initial namespace with the dedicated container’s namespace. Since one end of the veth pair has been moved into the container’s namespace whereas the other end remains in the initial namespace of the host, all network traffic from the container has to pass through the host-facing veth device allowing for attaching tc BPF programs on the tc ingress and egress hook of the veth. Network traffic going into the container will pass through the host-facing veth’s tc egress hook whereas network traffic coming from the container will pass through the host-facing veth’s tc ingress hook.
For virtual devices like veth devices XDP is unsuitable in this case since the kernel operates solely on a
skbhere and generic XDP has a few limitations where it does not operate with clonedskb’s. The latter is heavily used from the TCP/IP stack in order to hold data segments for retransmission where the generic XDP hook would simply get bypassed instead. Moreover, generic XDP needs to linearize the entireskbresulting in heavily degraded performance. tc BPF on the other hand is more flexible as it specializes on theskbinput context case and thus does not need to cope with the limitations from generic XDP.
Forwarding and load-balancing
The forwarding and load-balancing use case is quite similar to XDP, although slightly more targeted towards east-west container workloads rather than north-south traffic (though both technologies can be used in either case). Since XDP is only available on ingress side, tc BPF programs allow for further use cases that apply in particular on egress, for example, container based traffic can already be NATed and load-balanced on the egress side through BPF out of the initial namespace such that this is done transparent to the container itself. Egress traffic is already based on the
sk_buffstructure due to the nature of the kernel’s networking stack, so packet rewrites and redirects are suitable out of tc BPF. By utilizing thebpf_redirect()helper function, BPF can take over the forwarding logic to push the packet either into the ingress or egress path of another networking device. Thus, any bridge-like devices become unnecessary to use as well by utilizing tc BPF as forwarding fabric.
Flow sampling, monitoring
Like in XDP case, flow sampling and monitoring can be realized through a high-performance lockless per-CPU memory mapped perf ring buffer where the BPF program is able to push custom data, the full or truncated packet contents, or both up to a user space application. From the tc BPF program this is realized through the
bpf_skb_event_output()BPF helper function which has the same function signature and semantics asbpf_xdp_event_output(). Given tc BPF programs can be attached to ingress and egress as opposed to only ingress in XDP BPF case plus the two tc hooks are at the lowest layer in the (generic) networking stack, this allows for bidirectional monitoring of all network traffic from a particular node. This might be somewhat related to the cBPF case which tcpdump and Wireshark makes use of, though, without having to clone theskband with being a lot more flexible in terms of programmability where, for example, BPF can already perform in-kernel aggregation rather than pushing everything up to user space as well as custom annotations for packets pushed into the ring buffer. The latter is also heavily used in Cilium where packet drops can be further annotated to correlate container labels and reasons for why a given packet had to be dropped (such as due to policy violation) in order to provide a richer context.
Packet scheduler pre-processing
The
sch_clsact’s egress hook which is calledsch_handle_egress()runs right before taking the kernel’s qdisc root lock, thus tc BPF programs can be utilized to perform all the heavy lifting packet classification and mangling before the packet is transmitted into a real full blown qdisc such assch_htb. This type of interaction ofsch_clsactwith a real qdisc likesch_htbcoming later in the transmission phase allows to reduce the lock contention on transmission sincesch_clsact’s egress hook is executed without taking locks.
One concrete example user of tc BPF but also XDP BPF programs is Cilium. Cilium is open source software for transparently securing the network connectivity between application services deployed using Linux container management platforms like Docker and Kubernetes and operates at Layer 3/4 as well as Layer 7. At the heart of Cilium operates BPF in order to implement the policy enforcement as well as load balancing and monitoring.
- Slides: https://www.slideshare.net/ThomasGraf5/dockercon-2017-cilium-network-and-application-security-with-bpf-and-xdp
- Video: https://youtu.be/ilKlmTDdFgk
- Github: https://github.com/cilium/cilium
Driver support
Since tc BPF programs are triggered from the kernel’s networking stack and not directly out of the driver, they do not require any extra driver modification and therefore can run on any networking device. The only exception listed below is for offloading tc BPF programs to the NIC.
Drivers supporting offloaded tc BPF
- Netronome
- nfp [2]
Note that also here examples for writing and loading tc BPF programs are included in the toolchain section under the respective tools.
Further Reading¶
Mentioned lists of docs, projects, talks, papers, and further reading material are likely not complete. Thus, feel free to open pull requests to complete the list.
Kernel Developer FAQ¶
Under Documentation/bpf/, the Linux kernel provides two FAQ files that
are mainly targeted for kernel developers involved in the BPF subsystem.
BPF Devel FAQ: this document provides mostly information around patch submission process as well as BPF kernel tree, stable tree and bug reporting workflows, questions around BPF’s extensibility and interaction with LLVM and more.
BPF Design FAQ: this document tries to answer frequently asked questions around BPF design decisions related to the instruction set, verifier, calling convention, JITs, etc.
Projects using BPF¶
The following list includes a selection of open source projects making use of BPF respectively provide tooling for BPF. In this context the eBPF instruction set is specifically meant instead of projects utilizing the legacy cBPF:
Tracing
BCC
BCC stands for BPF Compiler Collection and its key feature is to provide a set of easy to use and efficient kernel tracing utilities all based upon BPF programs hooking into kernel infrastructure based upon kprobes, kretprobes, tracepoints, uprobes, uretprobes as well as USDT probes. The collection provides close to hundred tools targeting different layers across the stack from applications, system libraries, to the various different kernel subsystems in order to analyze a system’s performance characteristics or problems. Additionally, BCC provides an API in order to be used as a library for other projects.
bpftrace
bpftrace is a DTrace-style dynamic tracing tool for Linux and uses LLVM as a back end to compile scripts to BPF-bytecode and makes use of BCC for interacting with the kernel’s BPF tracing infrastructure. It provides a higher-level language for implementing tracing scripts compared to native BCC.
perf
The perf tool which is developed by the Linux kernel community as part of the kernel source tree provides a way to load tracing BPF programs through the conventional perf record subcommand where the aggregated data from BPF can be retrieved and post processed in perf.data for example through perf script and other means.
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/tools/perf
ply
ply is a tracing tool that follows the ‘Little Language’ approach of yore, and compiles ply scripts into Linux BPF programs that are attached to kprobes and tracepoints in the kernel. The scripts have a C-like syntax, heavily inspired by DTrace and by extension awk. ply keeps dependencies to very minimum and only requires flex and bison at build time, only libc at runtime.
systemtap
systemtap is a scripting language and tool for extracting, filtering and summarizing data in order to diagnose and analyze performance or functional problems. It comes with a BPF back end called stapbpf which translates the script directly into BPF without the need of an additional compiler and injects the probe into the kernel. Thus, unlike stap’s kernel modules this does neither have external dependencies nor requires to load kernel modules.
https://sourceware.org/git/gitweb.cgi?p=systemtap.git;a=summary
PCP
Performance Co-Pilot (PCP) is a system performance and analysis framework which is able to collect metrics through a variety of agents as well as analyze collected systems’ performance metrics in real-time or by using historical data. With pmdabcc, PCP has a BCC based performance metrics domain agent which extracts data from the kernel via BPF and BCC.
Weave Scope
Weave Scope is a cloud monitoring tool collecting data about processes, networking connections or other system data by making use of BPF in combination with kprobes. Weave Scope works on top of the gobpf library in order to load BPF ELF files into the kernel, and comes with a tcptracer-bpf tool which monitors connect, accept and close calls in order to trace TCP events.
Networking
Cilium
Cilium provides and transparently secures network connectivity and load-balancing between application workloads such as application containers or processes. Cilium operates at Layer 3/4 to provide traditional networking and security services as well as Layer 7 to protect and secure use of modern application protocols such as HTTP, gRPC and Kafka. It is integrated into orchestration frameworks such as Kubernetes and Mesos, and BPF is the foundational part of Cilium that operates in the kernel’s networking data path.
Suricata
Suricata is a network IDS, IPS and NSM engine, and utilizes BPF as well as XDP in three different areas, that is, as BPF filter in order to process or bypass certain packets, as a BPF based load balancer in order to allow for programmable load balancing and for XDP to implement a bypass or dropping mechanism at high packet rates.
http://suricata.readthedocs.io/en/latest/capture-hardware/ebpf-xdp.html
systemd
systemd allows for IPv4/v6 accounting as well as implementing network access control for its systemd units based on BPF’s cgroup ingress and egress hooks. Accounting is based on packets / bytes, and ACLs can be specified as address prefixes for allow / deny rules. More information can be found at:
http://0pointer.net/blog/ip-accounting-and-access-lists-with-systemd.html
iproute2
iproute2 offers the ability to load BPF programs as LLVM generated ELF files into the kernel. iproute2 supports both, XDP BPF programs as well as tc BPF programs through a common BPF loader backend. The tc and ip command line utilities enable loader and introspection functionality for the user.
https://git.kernel.org/pub/scm/network/iproute2/iproute2.git/
p4c-xdp
p4c-xdp presents a P4 compiler backend targeting BPF and XDP. P4 is a domain specific language describing how packets are processed by the data plane of a programmable network element such as NICs, appliances or switches, and with the help of p4c-xdp P4 programs can be translated into BPF C programs which can be compiled by clang / LLVM and loaded as BPF programs into the kernel at XDP layer for high performance packet processing.
Others
LLVM
clang / LLVM provides the BPF back end in order to compile C BPF programs into BPF instructions contained in ELF files. The LLVM BPF back end is developed alongside with the BPF core infrastructure in the Linux kernel and maintained by the same community. clang / LLVM is a key part in the toolchain for developing BPF programs.
libbpf
libbpf is a generic BPF library which is developed by the Linux kernel community as part of the kernel source tree and allows for loading and attaching BPF programs from LLVM generated ELF files into the kernel. The library is used by other kernel projects such as perf and bpftool.
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/tools/lib/bpf
bpftool
bpftool is the main tool for introspecting and debugging BPF programs and BPF maps, and like libbpf is developed by the Linux kernel community. It allows for dumping all active BPF programs and maps in the system, dumping and disassembling BPF or JITed BPF instructions from a program as well as dumping and manipulating BPF maps in the system. bpftool supports interaction with the BPF filesystem, loading various program types from an object file into the kernel and much more.
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/tools/bpf/bpftool
gobpf
gobpf provides go bindings for the bcc framework as well as low-level routines in order to load and use BPF programs from ELF files.
ebpf_asm
ebpf_asm provides an assembler for BPF programs written in an Intel-like assembly syntax, and therefore offers an alternative for writing BPF programs directly in assembly for cases where programs are rather small and simple without needing the clang / LLVM toolchain.
XDP Newbies¶
There are a couple of walk-through posts by David S. Miller to the xdp-newbies mailing list (http://vger.kernel.org/vger-lists.html#xdp-newbies), which explain various parts of XDP and BPF:
- May 2017,
- BPF Verifier Overview, David S. Miller, https://www.spinics.net/lists/xdp-newbies/msg00185.html
- May 2017,
- Contextually speaking…, David S. Miller, https://www.spinics.net/lists/xdp-newbies/msg00181.html
- May 2017,
- bpf.h and you…, David S. Miller, https://www.spinics.net/lists/xdp-newbies/msg00179.html
- Apr 2017,
- XDP example of the day, David S. Miller, https://www.spinics.net/lists/xdp-newbies/msg00009.html
BPF Newsletter¶
Alexander Alemayhu initiated a newsletter around BPF roughly once per week covering latest developments around BPF in Linux kernel land and its surrounding ecosystem in user space.
All BPF update newsletters (01 - 12) can be found here:
Podcasts¶
There have been a number of technical podcasts partially covering BPF. Incomplete list:
- Feb 2017,
- Linux Networking Update from Netdev Conference, Thomas Graf, Software Gone Wild, Show 71, http://blog.ipspace.net/2017/02/linux-networking-update-from-netdev.html http://media.blubrry.com/ipspace/stream.ipspace.net/nuggets/podcast/Show_71-NetDev_Update.mp3
- Jan 2017,
- The IO Visor Project, Brenden Blanco, OVS Orbit, Episode 23, https://ovsorbit.org/#e23 https://ovsorbit.org/episode-23.mp3
- Oct 2016,
- Fast Linux Packet Forwarding, Thomas Graf, Software Gone Wild, Show 64, http://blog.ipspace.net/2016/10/fast-linux-packet-forwarding-with.html http://media.blubrry.com/ipspace/stream.ipspace.net/nuggets/podcast/Show_64-Cilium_with_Thomas_Graf.mp3
- Aug 2016,
- P4 on the Edge, John Fastabend, OVS Orbit, Episode 11, https://ovsorbit.org/#e11 https://ovsorbit.org/episode-11.mp3
- May 2016,
- Cilium, Thomas Graf, OVS Orbit, Episode 4, https://ovsorbit.org/#e4 https://ovsorbit.benpfaff.org/episode-4.mp3
Blog posts¶
The following (incomplete) list includes blog posts around BPF, XDP and related projects:
- May 2017,
- An entertaining eBPF XDP adventure, Suchakra Sharma, https://suchakra.wordpress.com/2017/05/23/an-entertaining-ebpf-xdp-adventure/
- May 2017,
- eBPF, part 2: Syscall and Map Types, Ferris Ellis, https://ferrisellis.com/posts/ebpf_syscall_and_maps/
- May 2017,
- Monitoring the Control Plane, Gary Berger, http://firstclassfunc.com/2017/05/monitoring-the-control-plane/
- Apr 2017,
- USENIX/LISA 2016 Linux bcc/BPF Tools, Brendan Gregg, http://www.brendangregg.com/blog/2017-04-29/usenix-lisa-2016-bcc-bpf-tools.html
- Apr 2017,
- Liveblog: Cilium for Network and Application Security with BPF and XDP, Scott Lowe, http://blog.scottlowe.org//2017/04/18/black-belt-cilium/
- Apr 2017,
- eBPF, part 1: Past, Present, and Future, Ferris Ellis, https://ferrisellis.com/posts/ebpf_past_present_future/
- Mar 2017,
- Analyzing KVM Hypercalls with eBPF Tracing, Suchakra Sharma, https://suchakra.wordpress.com/2017/03/31/analyzing-kvm-hypercalls-with-ebpf-tracing/
- Jan 2017,
- Golang bcc/BPF Function Tracing, Brendan Gregg, http://www.brendangregg.com/blog/2017-01-31/golang-bcc-bpf-function-tracing.html
- Dec 2016,
- Give me 15 minutes and I’ll change your view of Linux tracing, Brendan Gregg, http://www.brendangregg.com/blog/2016-12-27/linux-tracing-in-15-minutes.html
- Nov 2016,
- Cilium: Networking and security for containers with BPF and XDP, Daniel Borkmann, https://opensource.googleblog.com/2016/11/cilium-networking-and-security.html
- Nov 2016,
- Linux bcc/BPF tcplife: TCP Lifespans, Brendan Gregg, http://www.brendangregg.com/blog/2016-11-30/linux-bcc-tcplife.html
- Oct 2016,
- DTrace for Linux 2016, Brendan Gregg, http://www.brendangregg.com/blog/2016-10-27/dtrace-for-linux-2016.html
- Oct 2016,
- Linux 4.9’s Efficient BPF-based Profiler, Brendan Gregg, http://www.brendangregg.com/blog/2016-10-21/linux-efficient-profiler.html
- Oct 2016,
- Linux bcc tcptop, Brendan Gregg, http://www.brendangregg.com/blog/2016-10-15/linux-bcc-tcptop.html
- Oct 2016,
- Linux bcc/BPF Node.js USDT Tracing, Brendan Gregg, http://www.brendangregg.com/blog/2016-10-12/linux-bcc-nodejs-usdt.html
- Oct 2016,
- Linux bcc/BPF Run Queue (Scheduler) Latency, Brendan Gregg, http://www.brendangregg.com/blog/2016-10-08/linux-bcc-runqlat.html
- Oct 2016,
- Linux bcc ext4 Latency Tracing, Brendan Gregg, http://www.brendangregg.com/blog/2016-10-06/linux-bcc-ext4dist-ext4slower.html
- Oct 2016,
- Linux MySQL Slow Query Tracing with bcc/BPF, Brendan Gregg, http://www.brendangregg.com/blog/2016-10-04/linux-bcc-mysqld-qslower.html
- Oct 2016,
- Linux bcc Tracing Security Capabilities, Brendan Gregg, http://www.brendangregg.com/blog/2016-10-01/linux-bcc-security-capabilities.html
- Sep 2016,
- Suricata bypass feature, Eric Leblond, https://www.stamus-networks.com/2016/09/28/suricata-bypass-feature/
- Aug 2016,
- Introducing the p0f BPF compiler, Gilberto Bertin, https://blog.cloudflare.com/introducing-the-p0f-bpf-compiler/
- Jun 2016,
- Ubuntu Xenial bcc/BPF, Brendan Gregg, http://www.brendangregg.com/blog/2016-06-14/ubuntu-xenial-bcc-bpf.html
- Mar 2016,
- Linux BPF/bcc Road Ahead, March 2016, Brendan Gregg, http://www.brendangregg.com/blog/2016-03-28/linux-bpf-bcc-road-ahead-2016.html
- Mar 2016,
- Linux BPF Superpowers, Brendan Gregg, http://www.brendangregg.com/blog/2016-03-05/linux-bpf-superpowers.html
- Feb 2016,
- Linux eBPF/bcc uprobes, Brendan Gregg, http://www.brendangregg.com/blog/2016-02-08/linux-ebpf-bcc-uprobes.html
- Feb 2016,
- Who is waking the waker? (Linux chain graph prototype), Brendan Gregg, http://www.brendangregg.com/blog/2016-02-05/ebpf-chaingraph-prototype.html
- Feb 2016,
- Linux Wakeup and Off-Wake Profiling, Brendan Gregg, http://www.brendangregg.com/blog/2016-02-01/linux-wakeup-offwake-profiling.html
- Jan 2016,
- Linux eBPF Off-CPU Flame Graph, Brendan Gregg, http://www.brendangregg.com/blog/2016-01-20/ebpf-offcpu-flame-graph.html
- Jan 2016,
- Linux eBPF Stack Trace Hack, Brendan Gregg, http://www.brendangregg.com/blog/2016-01-18/ebpf-stack-trace-hack.html
- Sep 2015,
- Linux Networking, Tracing and IO Visor, a New Systems Performance Tool for a Distributed World, Suchakra Sharma, https://thenewstack.io/comparing-dtrace-iovisor-new-systems-performance-platform-advance-linux-networking-virtualization/
- Aug 2015,
- BPF Internals - II, Suchakra Sharma, https://suchakra.wordpress.com/2015/08/12/bpf-internals-ii/
- May 2015,
- eBPF: One Small Step, Brendan Gregg, http://www.brendangregg.com/blog/2015-05-15/ebpf-one-small-step.html
- May 2015,
- BPF Internals - I, Suchakra Sharma, https://suchakra.wordpress.com/2015/05/18/bpf-internals-i/
- Jul 2014,
- Introducing the BPF Tools, Marek Majkowski, https://blog.cloudflare.com/introducing-the-bpf-tools/
- May 2014,
- BPF - the forgotten bytecode, Marek Majkowski, https://blog.cloudflare.com/bpf-the-forgotten-bytecode/
Talks¶
The following (incomplete) list includes talks and conference papers related to BPF and XDP:
- May 2017,
- PyCon 2017, Portland, Executing python functions in the linux kernel by transpiling to bpf, Alex Gartrell, https://www.youtube.com/watch?v=CpqMroMBGP4
- May 2017,
- gluecon 2017, Denver, Cilium + BPF: Least Privilege Security on API Call Level for Microservices, Dan Wendlandt, http://gluecon.com/#agenda
- May 2017,
- Lund Linux Con, Lund, XDP - eXpress Data Path, Jesper Dangaard Brouer, http://people.netfilter.org/hawk/presentations/LLC2017/XDP_DDoS_protecting_LLC2017.pdf
- May 2017,
- Polytechnique Montreal, Trace Aggregation and Collection with eBPF, Suchakra Sharma, http://step.polymtl.ca/~suchakra/eBPF-5May2017.pdf
- Apr 2017,
- DockerCon, Austin, Cilium - Network and Application Security with BPF and XDP, Thomas Graf, https://www.slideshare.net/ThomasGraf5/dockercon-2017-cilium-network-and-application-security-with-bpf-and-xdp
- Apr 2017,
- NetDev 2.1, Montreal, XDP Mythbusters, David S. Miller, https://www.netdevconf.org/2.1/slides/apr7/miller-XDP-MythBusters.pdf
- Apr 2017,
- NetDev 2.1, Montreal, Droplet: DDoS countermeasures powered by BPF + XDP, Huapeng Zhou, Doug Porter, Ryan Tierney, Nikita Shirokov, https://www.netdevconf.org/2.1/slides/apr6/zhou-netdev-xdp-2017.pdf
- Apr 2017,
- NetDev 2.1, Montreal, XDP in practice: integrating XDP in our DDoS mitigation pipeline, Gilberto Bertin, https://www.netdevconf.org/2.1/slides/apr6/bertin_Netdev-XDP.pdf
- Apr 2017,
- NetDev 2.1, Montreal, XDP for the Rest of Us, Andy Gospodarek, Jesper Dangaard Brouer, https://www.netdevconf.org/2.1/slides/apr7/gospodarek-Netdev2.1-XDP-for-the-Rest-of-Us_Final.pdf
- Mar 2017,
- SCALE15x, Pasadena, Linux 4.x Tracing: Performance Analysis with bcc/BPF, Brendan Gregg, https://www.slideshare.net/brendangregg/linux-4x-tracing-performance-analysis-with-bccbpf
- Mar 2017,
- XDP Inside and Out, David S. Miller, https://github.com/iovisor/bpf-docs/raw/master/XDP_Inside_and_Out.pdf
- Mar 2017,
- OpenSourceDays, Copenhagen, XDP - eXpress Data Path, Used for DDoS protection, Jesper Dangaard Brouer, https://github.com/iovisor/bpf-docs/raw/master/XDP_Inside_and_Out.pdf
- Mar 2017,
- source{d}, Infrastructure 2017, Madrid, High-performance Linux monitoring with eBPF, Alfonso Acosta, https://www.youtube.com/watch?v=k4jqTLtdrxQ
- Feb 2017,
- FOSDEM 2017, Brussels, Stateful packet processing with eBPF, an implementation of OpenState interface, Quentin Monnet, https://fosdem.org/2017/schedule/event/stateful_ebpf/
- Feb 2017,
- FOSDEM 2017, Brussels, eBPF and XDP walkthrough and recent updates, Daniel Borkmann, http://borkmann.ch/talks/2017_fosdem.pdf
- Feb 2017,
- FOSDEM 2017, Brussels, Cilium - BPF & XDP for containers, Thomas Graf, https://fosdem.org/2017/schedule/event/cilium/
- Jan 2017,
- linuxconf.au, Hobart, BPF: Tracing and more, Brendan Gregg, https://www.slideshare.net/brendangregg/bpf-tracing-and-more
- Dec 2016,
- USENIX LISA 2016, Boston, Linux 4.x Tracing Tools: Using BPF Superpowers, Brendan Gregg, https://www.slideshare.net/brendangregg/linux-4x-tracing-tools-using-bpf-superpowers
- Nov 2016,
- Linux Plumbers, Santa Fe, Cilium: Networking & Security for Containers with BPF & XDP, Thomas Graf, http://www.slideshare.net/ThomasGraf5/clium-container-networking-with-bpf-xdp
- Nov 2016,
- OVS Conference, Santa Clara, Offloading OVS Flow Processing using eBPF, William (Cheng-Chun) Tu, http://openvswitch.org/support/ovscon2016/7/1120-tu.pdf
- Oct 2016,
- One.com, Copenhagen, XDP - eXpress Data Path, Intro and future use-cases, Jesper Dangaard Brouer, http://people.netfilter.org/hawk/presentations/xdp2016/xdp_intro_and_use_cases_sep2016.pdf
- Oct 2016,
- Docker Distributed Systems Summit, Berlin, Cilium: Networking & Security for Containers with BPF & XDP, Thomas Graf, http://www.slideshare.net/Docker/cilium-bpf-xdp-for-containers-66969823
- Oct 2016,
- NetDev 1.2, Tokyo, Data center networking stack, Tom Herbert, http://netdevconf.org/1.2/session.html?tom-herbert
- Oct 2016,
- NetDev 1.2, Tokyo, Fast Programmable Networks & Encapsulated Protocols, David S. Miller, http://netdevconf.org/1.2/session.html?david-miller-keynote
- Oct 2016,
- NetDev 1.2, Tokyo, XDP workshop - Introduction, experience, and future development, Tom Herbert, http://netdevconf.org/1.2/session.html?herbert-xdp-workshop
- Oct 2016,
- NetDev1.2, Tokyo, The adventures of a Suricate in eBPF land, Eric Leblond, http://netdevconf.org/1.2/slides/oct6/10_suricata_ebpf.pdf
- Oct 2016,
- NetDev1.2, Tokyo, cls_bpf/eBPF updates since netdev 1.1, Daniel Borkmann, http://borkmann.ch/talks/2016_tcws.pdf
- Oct 2016,
- NetDev1.2, Tokyo, Advanced programmability and recent updates with tc’s cls_bpf, Daniel Borkmann, http://borkmann.ch/talks/2016_netdev2.pdf http://www.netdevconf.org/1.2/papers/borkmann.pdf
- Oct 2016,
- NetDev 1.2, Tokyo, eBPF/XDP hardware offload to SmartNICs, Jakub Kicinski, Nic Viljoen, http://netdevconf.org/1.2/papers/eBPF_HW_OFFLOAD.pdf
- Aug 2016,
- LinuxCon, Toronto, What Can BPF Do For You?, Brenden Blanco, https://events.linuxfoundation.org/sites/events/files/slides/iovisor-lc-bof-2016.pdf
- Aug 2016,
- LinuxCon, Toronto, Cilium - Fast IPv6 Container Networking with BPF and XDP, Thomas Graf, https://www.slideshare.net/ThomasGraf5/cilium-fast-ipv6-container-networking-with-bpf-and-xdp
- Aug 2016,
- P4, EBPF and Linux TC Offload, Dinan Gunawardena, Jakub Kicinski, https://de.slideshare.net/Open-NFP/p4-epbf-and-linux-tc-offload
- Jul 2016,
- Linux Meetup, Santa Clara, eXpress Data Path, Brenden Blanco, http://www.slideshare.net/IOVisor/express-data-path-linux-meetup-santa-clara-july-2016
- Jul 2016,
- Linux Meetup, Santa Clara, CETH for XDP, Yan Chan, Yunsong Lu, http://www.slideshare.net/IOVisor/ceth-for-xdp-linux-meetup-santa-clara-july-2016
- May 2016,
- P4 workshop, Stanford, P4 on the Edge, John Fastabend, https://schd.ws/hosted_files/2016p4workshop/1d/Intel%20Fastabend-P4%20on%20the%20Edge.pdf
- Mar 2016,
- Performance @Scale 2016, Menlo Park, Linux BPF Superpowers, Brendan Gregg, https://www.slideshare.net/brendangregg/linux-bpf-superpowers
- Mar 2016,
- eXpress Data Path, Tom Herbert, Alexei Starovoitov, https://github.com/iovisor/bpf-docs/raw/master/Express_Data_Path.pdf
- Feb 2016,
- NetDev1.1, Seville, On getting tc classifier fully programmable with cls_bpf, Daniel Borkmann, http://borkmann.ch/talks/2016_netdev.pdf http://www.netdevconf.org/1.1/proceedings/papers/On-getting-tc-classifier-fully-programmable-with-cls-bpf.pdf
- Jan 2016,
- FOSDEM 2016, Brussels, Linux tc and eBPF, Daniel Borkmann, http://borkmann.ch/talks/2016_fosdem.pdf
- Oct 2015,
- LinuxCon Europe, Dublin, eBPF on the Mainframe, Michael Holzheu, https://events.linuxfoundation.org/sites/events/files/slides/ebpf_on_the_mainframe_lcon_2015.pdf
- Aug 2015,
- Tracing Summit, Seattle, LLTng’s Trace Filtering and beyond (with some eBPF goodness, of course!), Suchakra Sharma, https://github.com/iovisor/bpf-docs/raw/master/ebpf_excerpt_20Aug2015.pdf
- Jun 2015,
- LinuxCon Japan, Tokyo, Exciting Developments in Linux Tracing, Elena Zannoni, https://events.linuxfoundation.org/sites/events/files/slides/tracing-linux-ezannoni-linuxcon-ja-2015_0.pdf
- Feb 2015,
- Collaboration Summit, Santa Rosa, BPF: In-kernel Virtual Machine, Alexei Starovoitov, https://events.linuxfoundation.org/sites/events/files/slides/bpf_collabsummit_2015feb20.pdf
- Feb 2015,
- NetDev 0.1, Ottawa, BPF: In-kernel Virtual Machine, Alexei Starovoitov, http://netdevconf.org/0.1/sessions/15.html
- Feb 2014,
- DevConf.cz, Brno, tc and cls_bpf: lightweight packet classifying with BPF, Daniel Borkmann, http://borkmann.ch/talks/2014_devconf.pdf
Further Documents¶
- Dive into BPF: a list of reading material, Quentin Monnet (https://qmonnet.github.io/whirl-offload/2016/09/01/dive-into-bpf/)
- XDP - eXpress Data Path, Jesper Dangaard Brouer (https://prototype-kernel.readthedocs.io/en/latest/networking/XDP/index.html)
API Reference¶
Introduction¶
The Cilium API is JSON based and provided by the cilium-agent. The purpose
of the API is to provide visibility and control over an individual agent
instance. In general, all API calls affect only the resources managed by the
individual cilium-agent serving the API. A few selected API calls such as
the security identity resolution provides cluster wide visibility. Such API
calls are marked specifically. Unless noted otherwise, API calls will only affect
local agent resources.
How to access the API¶
CLI Client¶
The easiest way to access the API is via the cilium CLI client. cilium
will automatically locate the API of the agent running on the same node and
access it. However, using the -H or --host flag, the cilium client
can be pointed to an arbitrary API address.
Example¶
$ cilium -H unix:///var/run/cilium/cilium.sock
[...]
Golang Package¶
The following Go packages can be used to access the API:
| Package | Description |
| pkg/client | Main client API abstraction |
| api/v1/models | API resource data type models |
Example¶
The full example can be found in the cilium/client-example repository.
import (
"fmt"
"github.com/cilium/cilium/pkg/client"
)
func main() {
c, err := client.NewDefaultClient()
if err != nil {
...
}
endpoints, err := c.EndpointList()
if err != nil {
...
}
for _, ep := range endpoints {
fmt.Printf("%8d %14s %16s %32s\n", ep.ID, ep.ContainerName, ep.Addressing.IPV4, ep.Addressing.IPV6)
}
Compatibility Guarantees¶
Cilium API is stable as of version 1.0, backward compatibility will be upheld for whole lifecycle of Cilium 1.x.
API Reference¶
-
GET/healthz¶ Get health of Cilium daemon
Returns health and status information of the Cilium daemon and related components such as the local container runtime, connected datastore, Kubernetes integration.
Status Codes: - 200 OK – Success
-
GET/config¶ Get configuration of Cilium daemon
Returns the configuration of the Cilium daemon.
Status Codes: - 200 OK – Success
-
PATCH/config¶ Modify daemon configuration
Updates the daemon configuration by applying the provided ConfigurationMap and regenerates & recompiles all required datapath components.
Status Codes: - 200 OK – Success
- 400 Bad Request – Bad configuration parameters
- 500 Internal Server Error – Recompilation failed
-
GET/endpoint/{id}¶ Get endpoint by endpoint ID
Returns endpoint information
Parameters: - id (string) –
String describing an endpoint with the format
[prefix:]id. If no prefix is specified, a prefix ofcilium-local:is assumed. Not all endpoints will be addressable by all endpoint ID prefixes with the exception of the local Cilium UUID which is assigned to all endpoints.- Supported endpoint id prefixes:
- cilium-local: Local Cilium endpoint UUID, e.g. cilium-local:3389595
- cilium-global: Global Cilium endpoint UUID, e.g. cilium-global:cluster1:nodeX:452343
- container-id: Container runtime ID, e.g. container-id:22222
- container-name: Container name, e.g. container-name:foobar
- pod-name: pod name for this container if K8s is enabled, e.g. pod-name:default:foobar
- docker-endpoint: Docker libnetwork endpoint ID, e.g. docker-endpoint:4444
Status Codes: - 200 OK – Success
- 400 Bad Request – Invalid endpoint ID format for specified type
- 404 Not Found – Endpoint not found
- id (string) –
-
PUT/endpoint/{id}¶ Create endpoint
Creates a new endpoint
Parameters: - id (string) –
String describing an endpoint with the format
[prefix:]id. If no prefix is specified, a prefix ofcilium-local:is assumed. Not all endpoints will be addressable by all endpoint ID prefixes with the exception of the local Cilium UUID which is assigned to all endpoints.- Supported endpoint id prefixes:
- cilium-local: Local Cilium endpoint UUID, e.g. cilium-local:3389595
- cilium-global: Global Cilium endpoint UUID, e.g. cilium-global:cluster1:nodeX:452343
- container-id: Container runtime ID, e.g. container-id:22222
- container-name: Container name, e.g. container-name:foobar
- pod-name: pod name for this container if K8s is enabled, e.g. pod-name:default:foobar
- docker-endpoint: Docker libnetwork endpoint ID, e.g. docker-endpoint:4444
Status Codes: - 201 Created – Created
- 400 Bad Request – Invalid endpoint in request
- 409 Conflict – Endpoint already exists
- 500 Internal Server Error – Endpoint creation failed
- id (string) –
-
PATCH/endpoint/{id}¶ Modify existing endpoint
Applies the endpoint change request to an existing endpoint
Parameters: - id (string) –
String describing an endpoint with the format
[prefix:]id. If no prefix is specified, a prefix ofcilium-local:is assumed. Not all endpoints will be addressable by all endpoint ID prefixes with the exception of the local Cilium UUID which is assigned to all endpoints.- Supported endpoint id prefixes:
- cilium-local: Local Cilium endpoint UUID, e.g. cilium-local:3389595
- cilium-global: Global Cilium endpoint UUID, e.g. cilium-global:cluster1:nodeX:452343
- container-id: Container runtime ID, e.g. container-id:22222
- container-name: Container name, e.g. container-name:foobar
- pod-name: pod name for this container if K8s is enabled, e.g. pod-name:default:foobar
- docker-endpoint: Docker libnetwork endpoint ID, e.g. docker-endpoint:4444
Status Codes: - 200 OK – Success
- 400 Bad Request – Invalid modify endpoint request
- 404 Not Found – Endpoint does not exist
- 500 Internal Server Error – Endpoint update failed
- id (string) –
-
DELETE/endpoint/{id}¶ Delete endpoint
Deletes the endpoint specified by the ID. Deletion is imminent and atomic, if the deletion request is valid and the endpoint exists, deletion will occur even if errors are encountered in the process. If errors have been encountered, the code 202 will be returned, otherwise 200 on success.
All resources associated with the endpoint will be freed and the workload represented by the endpoint will be disconnected.It will no longer be able to initiate or receive communications of any sort.
Parameters: - id (string) –
String describing an endpoint with the format
[prefix:]id. If no prefix is specified, a prefix ofcilium-local:is assumed. Not all endpoints will be addressable by all endpoint ID prefixes with the exception of the local Cilium UUID which is assigned to all endpoints.- Supported endpoint id prefixes:
- cilium-local: Local Cilium endpoint UUID, e.g. cilium-local:3389595
- cilium-global: Global Cilium endpoint UUID, e.g. cilium-global:cluster1:nodeX:452343
- container-id: Container runtime ID, e.g. container-id:22222
- container-name: Container name, e.g. container-name:foobar
- pod-name: pod name for this container if K8s is enabled, e.g. pod-name:default:foobar
- docker-endpoint: Docker libnetwork endpoint ID, e.g. docker-endpoint:4444
Status Codes: - 200 OK – Success
- 206 Partial Content – Deleted with a number of errors encountered
- 400 Bad Request – Invalid endpoint ID format for specified type. Details in error message
- 404 Not Found – Endpoint not found
- id (string) –
-
GET/endpoint¶ Retrieves a list of endpoints that have metadata matching the provided parameters.
Retrieves a list of endpoints that have metadata matching the provided parameters, or all endpoints if no parameters provided.
Status Codes: - 200 OK – Success
- 404 Not Found – Endpoints with provided parameters not found
-
GET/endpoint/{id}/config¶ Retrieve endpoint configuration
Retrieves the configuration of the specified endpoint.
Parameters: - id (string) –
String describing an endpoint with the format
[prefix:]id. If no prefix is specified, a prefix ofcilium-local:is assumed. Not all endpoints will be addressable by all endpoint ID prefixes with the exception of the local Cilium UUID which is assigned to all endpoints.- Supported endpoint id prefixes:
- cilium-local: Local Cilium endpoint UUID, e.g. cilium-local:3389595
- cilium-global: Global Cilium endpoint UUID, e.g. cilium-global:cluster1:nodeX:452343
- container-id: Container runtime ID, e.g. container-id:22222
- container-name: Container name, e.g. container-name:foobar
- pod-name: pod name for this container if K8s is enabled, e.g. pod-name:default:foobar
- docker-endpoint: Docker libnetwork endpoint ID, e.g. docker-endpoint:4444
Status Codes: - 200 OK – Success
- 404 Not Found – Endpoint not found
- id (string) –
-
PATCH/endpoint/{id}/config¶ Modify mutable endpoint configuration
Update the configuration of an existing endpoint and regenerates & recompiles the corresponding programs automatically.
Parameters: - id (string) –
String describing an endpoint with the format
[prefix:]id. If no prefix is specified, a prefix ofcilium-local:is assumed. Not all endpoints will be addressable by all endpoint ID prefixes with the exception of the local Cilium UUID which is assigned to all endpoints.- Supported endpoint id prefixes:
- cilium-local: Local Cilium endpoint UUID, e.g. cilium-local:3389595
- cilium-global: Global Cilium endpoint UUID, e.g. cilium-global:cluster1:nodeX:452343
- container-id: Container runtime ID, e.g. container-id:22222
- container-name: Container name, e.g. container-name:foobar
- pod-name: pod name for this container if K8s is enabled, e.g. pod-name:default:foobar
- docker-endpoint: Docker libnetwork endpoint ID, e.g. docker-endpoint:4444
Status Codes: - 200 OK – Success
- 400 Bad Request – Invalid configuration request
- 404 Not Found – Endpoint not found
- 500 Internal Server Error – Update failed. Details in message.
- id (string) –
-
GET/endpoint/{id}/labels¶ Retrieves the list of labels associated with an endpoint.
Parameters: - id (string) –
String describing an endpoint with the format
[prefix:]id. If no prefix is specified, a prefix ofcilium-local:is assumed. Not all endpoints will be addressable by all endpoint ID prefixes with the exception of the local Cilium UUID which is assigned to all endpoints.- Supported endpoint id prefixes:
- cilium-local: Local Cilium endpoint UUID, e.g. cilium-local:3389595
- cilium-global: Global Cilium endpoint UUID, e.g. cilium-global:cluster1:nodeX:452343
- container-id: Container runtime ID, e.g. container-id:22222
- container-name: Container name, e.g. container-name:foobar
- pod-name: pod name for this container if K8s is enabled, e.g. pod-name:default:foobar
- docker-endpoint: Docker libnetwork endpoint ID, e.g. docker-endpoint:4444
Status Codes: - 200 OK – Success
- 404 Not Found – Endpoint not found
- id (string) –
-
PATCH/endpoint/{id}/labels¶ Set label configuration of endpoint
Sets labels associated with an endpoint. These can be user provided or derived from the orchestration system.
Parameters: - id (string) –
String describing an endpoint with the format
[prefix:]id. If no prefix is specified, a prefix ofcilium-local:is assumed. Not all endpoints will be addressable by all endpoint ID prefixes with the exception of the local Cilium UUID which is assigned to all endpoints.- Supported endpoint id prefixes:
- cilium-local: Local Cilium endpoint UUID, e.g. cilium-local:3389595
- cilium-global: Global Cilium endpoint UUID, e.g. cilium-global:cluster1:nodeX:452343
- container-id: Container runtime ID, e.g. container-id:22222
- container-name: Container name, e.g. container-name:foobar
- pod-name: pod name for this container if K8s is enabled, e.g. pod-name:default:foobar
- docker-endpoint: Docker libnetwork endpoint ID, e.g. docker-endpoint:4444
Status Codes: - 200 OK – Success
- 404 Not Found – Endpoint not found
- 500 Internal Server Error – Error while updating labels
- id (string) –
-
GET/endpoint/{id}/log¶ Retrieves the status logs associated with this endpoint.
Parameters: - id (string) –
String describing an endpoint with the format
[prefix:]id. If no prefix is specified, a prefix ofcilium-local:is assumed. Not all endpoints will be addressable by all endpoint ID prefixes with the exception of the local Cilium UUID which is assigned to all endpoints.- Supported endpoint id prefixes:
- cilium-local: Local Cilium endpoint UUID, e.g. cilium-local:3389595
- cilium-global: Global Cilium endpoint UUID, e.g. cilium-global:cluster1:nodeX:452343
- container-id: Container runtime ID, e.g. container-id:22222
- container-name: Container name, e.g. container-name:foobar
- pod-name: pod name for this container if K8s is enabled, e.g. pod-name:default:foobar
- docker-endpoint: Docker libnetwork endpoint ID, e.g. docker-endpoint:4444
Status Codes: - 200 OK – Success
- 400 Bad Request – Invalid identity provided
- 404 Not Found – Endpoint not found
- id (string) –
-
GET/endpoint/{id}/healthz¶ Retrieves the status logs associated with this endpoint.
Parameters: - id (string) –
String describing an endpoint with the format
[prefix:]id. If no prefix is specified, a prefix ofcilium-local:is assumed. Not all endpoints will be addressable by all endpoint ID prefixes with the exception of the local Cilium UUID which is assigned to all endpoints.- Supported endpoint id prefixes:
- cilium-local: Local Cilium endpoint UUID, e.g. cilium-local:3389595
- cilium-global: Global Cilium endpoint UUID, e.g. cilium-global:cluster1:nodeX:452343
- container-id: Container runtime ID, e.g. container-id:22222
- container-name: Container name, e.g. container-name:foobar
- pod-name: pod name for this container if K8s is enabled, e.g. pod-name:default:foobar
- docker-endpoint: Docker libnetwork endpoint ID, e.g. docker-endpoint:4444
Status Codes: - 200 OK – Success
- 400 Bad Request – Invalid identity provided
- 404 Not Found – Endpoint not found
- id (string) –
-
GET/identity¶ Retrieves a list of identities that have metadata matching the provided parameters.
Retrieves a list of identities that have metadata matching the provided parameters, or all identities if no parameters are provided.
Status Codes: - 200 OK – Success
- 404 Not Found – Identities with provided parameters not found
- 520 – Identity storage unreachable. Likely a network problem.
- 521 – Invalid identity format in storage
-
GET/identity/{id}¶ Retrieve identity
Parameters: - id (string) – Cluster wide unique identifier of a security identity.
Status Codes: - 200 OK – Success
- 400 Bad Request – Invalid identity provided
- 404 Not Found – Identity not found
- 520 – Identity storage unreachable. Likely a network problem.
- 521 – Invalid identity format in storage
-
POST/ipam¶ Allocate an IP address
Query Parameters: - family (string) –
- owner (string) –
Status Codes: - 201 Created – Success
- 502 Bad Gateway – Allocation failure
-
POST/ipam/{ip}¶ Allocate an IP address
Parameters: - ip (string) – IP address
Query Parameters: - owner (string) –
Status Codes: - 200 OK – Success
- 400 Bad Request – Invalid IP address
- 409 Conflict – IP already allocated
- 500 Internal Server Error – IP allocation failure. Details in message.
- 501 Not Implemented – Allocation for address family disabled
-
DELETE/ipam/{ip}¶ Release an allocated IP address
Parameters: - ip (string) – IP address or owner name
Status Codes: - 200 OK – Success
- 400 Bad Request – Invalid IP address
- 404 Not Found – IP address not found
- 500 Internal Server Error – Address release failure
- 501 Not Implemented – Allocation for address family disabled
-
GET/policy¶ Retrieve entire policy tree
Returns the entire policy tree with all children.
Status Codes: - 200 OK – Success
- 404 Not Found – No policy rules found
-
PUT/policy¶ Create or update a policy (sub)tree
Status Codes: - 200 OK – Success
- 400 Bad Request – Invalid policy
- 460 – Invalid path
- 500 Internal Server Error – Policy import failed
-
DELETE/policy¶ Delete a policy (sub)tree
Status Codes: - 200 OK – Success
- 400 Bad Request – Invalid request
- 404 Not Found – Policy not found
- 500 Internal Server Error – Error while deleting policy
-
GET/service/{id}¶ Retrieve configuration of a service
Parameters: - id (integer) – ID of service
Status Codes: - 200 OK – Success
- 404 Not Found – Service not found
-
PUT/service/{id}¶ Create or update service
Parameters: - id (integer) – ID of service
Status Codes: - 200 OK – Updated
- 201 Created – Created
- 460 – Invalid frontend in service configuration
- 461 – Invalid backend in service configuration
- 500 Internal Server Error – Error while creating service
-
DELETE/service/{id}¶ Delete a service
Parameters: - id (integer) – ID of service
Status Codes: - 200 OK – Success
- 404 Not Found – Service not found
- 500 Internal Server Error – Service deletion failed
-
GET/prefilter¶ Retrieve list of CIDRs
Status Codes: - 200 OK – Success
- 500 Internal Server Error – Prefilter get failed
-
PATCH/prefilter¶ Update list of CIDRs
Status Codes: - 200 OK – Updated
- 461 – Invalid CIDR prefix
- 500 Internal Server Error – Prefilter update failed
-
GET/debuginfo¶ Retrieve information about the agent and evironment for debugging
Status Codes: - 200 OK – Success
- 500 Internal Server Error – DebugInfo get failed
-
GET/map/{name}¶ Retrieve contents of BPF map
Parameters: - name (string) – Name of map
Status Codes: - 200 OK – Success
- 404 Not Found – Map not found
-
GET/metrics/¶ Retrieve cilium metrics
Status Codes: - 200 OK – Success
- 500 Internal Server Error – Metrics cannot be retrieved
-
GET/fqdn/cache¶ Retrieves the list of DNS lookups intercepted from all endpoints.
Retrieves the list of DNS lookups intercepted from endpoints, optionally filtered by endpoint id, DNS name, or CIDR IP range.
Query Parameters: - matchpattern (string) – A toFQDNs compatible matchPattern expression
- cidr (string) – A CIDR range of IPs
Status Codes: - 200 OK – Success
- 400 Bad Request – Invalid request (error parsing parameters)
- 404 Not Found – No DNS data with provided parameters found
-
DELETE/fqdn/cache¶ Deletes matching DNS lookups from the policy-generation cache.
Deletes matching DNS lookups from the cache, optionally restricted by DNS name. The removed IP data will no longer be used in generated policies.
Query Parameters: - matchpattern (string) – A toFQDNs compatible matchPattern expression
Status Codes: - 200 OK – Success
- 400 Bad Request – Invalid request (error parsing parameters)
-
GET/fqdn/cache/{id}¶ Retrieves the list of DNS lookups intercepted from an endpoint.
Retrieves the list of DNS lookups intercepted from endpoints, optionally filtered by endpoint id, DNS name, or CIDR IP range.
Parameters: - id (string) –
String describing an endpoint with the format
[prefix:]id. If no prefix is specified, a prefix ofcilium-local:is assumed. Not all endpoints will be addressable by all endpoint ID prefixes with the exception of the local Cilium UUID which is assigned to all endpoints.- Supported endpoint id prefixes:
- cilium-local: Local Cilium endpoint UUID, e.g. cilium-local:3389595
- cilium-global: Global Cilium endpoint UUID, e.g. cilium-global:cluster1:nodeX:452343
- container-id: Container runtime ID, e.g. container-id:22222
- container-name: Container name, e.g. container-name:foobar
- pod-name: pod name for this container if K8s is enabled, e.g. pod-name:default:foobar
- docker-endpoint: Docker libnetwork endpoint ID, e.g. docker-endpoint:4444
Query Parameters: - matchpattern (string) – A toFQDNs compatible matchPattern expression
- cidr (string) – A CIDR range of IPs
Status Codes: - 200 OK – Success
- 400 Bad Request – Invalid request (error parsing parameters)
- 404 Not Found – No DNS data with provided parameters found
- id (string) –
Command Cheatsheet¶
Cilium is controlled via an easy command-line interface. This CLI is a single application that takes subcommands that you can find in the command reference guide.
$ cilium
CLI for interacting with the local Cilium Agent
Usage:
cilium [command]
Available Commands:
bpf Direct access to local BPF maps
cleanup Reset the agent state
completion Output shell completion code for bash
config Cilium configuration options
debuginfo Request available debugging information from agent
endpoint Manage endpoints
identity Manage security identities
kvstore Direct access to the kvstore
monitor Monitoring
policy Manage security policies
prefilter Manage XDP CIDR filters
service Manage services & loadbalancers
status Display status of daemon
version Print version information
Flags:
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
Use "cilium [command] --help" for more information about a command.
All commands and subcommands have the option -h that will provide information
about the options and arguments that the subcommand has. In case of any error in
the command, Cilium CLI will return a non-zero status.
Command utilities:¶
JSON Output¶
All the list commands will return a pretty printed list with the information
retrieved from Cilium Daemon. If you need something more detailed you can use JSON
output, to get the JSON output you can use the global option -o json
$ cilium endpoint list -o json
Moreover, Cilium also provides a JSONPath support, so detailed information can be extracted. JSONPath template reference can be found in Kubernetes documentation
$ cilium endpoint list -o jsonpath='{[*].id}'
29898 38939 56326
$ cilium endpoint list -o jsonpath='{range [*]}{@.id}{"="}{@.status.policy.spec.policy-enabled}{"\n"}{end}'
29898=none
38939=none
56326=none
Shell Tab-completion¶
If you use bash or zsh, Cilium CLI can provide tab completion for subcommands. If you want to install tab completion, you should run the following command in your terminal.
$ source <(cilium completion)
If you want to have Cilium completion always loaded, you can install using the following:
$ echo "source <(cilium completion)" >> ~/.bashrc
Command examples:¶
Basics¶
Check the status of the agent
$ cilium status
KVStore: Ok Consul: 172.17.0.3:8300
ContainerRuntime: Ok
Kubernetes: Disabled
Cilium: Ok OK
NodeMonitor: Listening for events on 2 CPUs with 64x4096 of shared memory
Cilium health daemon: Ok
Controller Status: 6/6 healthy
Proxy Status: OK, ip 10.15.28.238, port-range 10000-20000
Cluster health: 1/1 reachable (2018-04-11T07:33:09Z)
$
Get a detailed status of the agent:
$ cilium status --all-controllers --all-health --all-redirects
KVStore: Ok Consul: 172.17.0.3:8300
ContainerRuntime: Ok
Kubernetes: Disabled
Cilium: Ok OK
NodeMonitor: Listening for events on 2 CPUs with 64x4096 of shared memory
Cilium health daemon: Ok
Controller Status: 6/6 healthy
Name Last success Last error Count Message
kvstore-lease-keepalive 2m52s ago never 0 no error
ipcache-bpf-garbage-collection 2m50s ago never 0 no error
resolve-identity-29898 2m50s ago never 0 no error
sync-identity-to-k8s-pod (29898) 50s ago never 0 no error
sync-IPv4-identity-mapping (29898) 2m49s ago never 0 no error
sync-IPv6-identity-mapping (29898) 2m49s ago never 0 no error
Proxy Status: OK, ip 10.15.28.238, port-range 10000-20000
Cluster health: 1/1 reachable (2018-04-11T07:32:09Z)
Name IP Reachable Endpoints reachable
runtime (localhost) 10.0.2.15 true false
$
Get the current agent configuration
cilium config
Policy management¶
Importing a Cilium Network Policy
cilium policy import my-policy.json
Get list of all imported policy rules
cilium policy get
Remove all policies
cilium policy delete --all
Tracing¶
Check policy enforcement between two labels on port 80:
cilium policy trace -s <app.from> -d <app.to> --dport 80
Check policy enforcement between two identities
cilium policy trace --src-identity <from-id> --dst-identity <to-id>
Check policy enforcement between two pods:
cilium policy trace --src-k8s-pod <namespace>:<pod.from> --dst-k8s-pod <namespace>:<pod.to>
Monitoring¶
Monitor cilium datapath notifications
cilium monitor
Verbose output (including debug if enabled)
cilium monitor -v
Filter for only the events related to endpoint
cilium monitor --related-to=<id>
Filter for only events on layer 7
cilium monitor -t L7
Show notifications only for dropped packet events
cilium monitor --type drop
Don’t dissect packet payload, display payload in hex information
cilium monitor -v --hex
Connectivity¶
Check cluster Connectivity
cilium-health status
There is also a blog post related to this tool.
Endpoints¶
Get list of all local endpoints
cilium endpoint list
Get detailed view of endpoint properties and state
cilium endpoint get <id>
Show recent endpoint specific log entries
cilium endpoint log <id>
Enable debugging output on the cilium monitor for this endpoint
cilium endpoint config <id> Debug=true
Loadbalancing¶
Get list of loadbalancer services
cilium service list
Or you can get the loadbalancer information using bpf list ::
cilium bpf lb list
Add a new loadbalancer
cilium service update --frontend 127.0.0.1:80 \
--backends 127.0.0.2:90,127.0.0.3:90 \
--id 20 \
--rev 2
BPF¶
List node tunneling mapping information
cilium bpf tunnel list
Checking logs for verifier issue
journalctl -u cilium | grep -B20 -F10 Verifier
List connection tracking entries:
sudo cilium bpf ct list global
Flush connection tracking entries:
sudo cilium bpf ct flush
List proxy configuration:
sudo cilium bpf proxy list
Kubernetes examples:¶
If you running Cilium on top of Kubernetes you may also want a way to list all cilium endpoints or policies from a single Kubectl commands. Cilium provides all this information to the user by using Kubernetes Resource Definitions:
Policies¶
In Kubernetes you can use two kinds of policies, Kubernetes Network Policies or
Cilium Network Policies. Both can be retrieved from the kubectl command:
kubectl get netpol
$ kubectl get cnp
NAME AGE
rule1 3m
$ kubectl get cnp rule1
NAME AGE
rule1 3m
$ kubectl get cnp rule1 -o json
Endpoints¶
To retrieve a list of all endpoints managed by cilium, Cilum Endpoint
resource can be used.
$ kubectl get cep
NAME AGE
34e299f0-b25c2fef 41s
34e299f0-dd86986c 42s
4d088f48-83e4f98d 2m
4d088f48-d04ab55f 2m
5c6211b5-9217a4d1 1m
5c6211b5-dccc3d24 1m
700e0976-6cb50b02 3m
700e0976-afd3a30c 3m
78092a35-4874ed16 1m
78092a35-4b08b92b 1m
9b74f61f-14571299 7s
9b74f61f-f9a96f4a 7s
$ kubectl get cep 700e0976-6cb50b02 -o json
$ kubectl get cep -o jsonpath='{range .items[*]}{@.status.id}{"="}{@.status.status.policy.spec.policy-enabled}{"\n"}{end}'
30391=ingress
5766=ingress
51796=none
40355=none
Microscope¶
Cilium also provides an option to monitor all connections from all Kubernetes nodes. Microscope is a distributed monitor that connects to all Cilium instances and retrieves monitor information from there.
Cilium also provides the ability to monitor all cilium-managed connections in the kubernetes cluster via Microscope. It is a distributed monitor that connects to all Cilium instances and retrieves monitor information from each node.
Microscope can be installed an run as a pod, the basic usage is the following:
$ kubectl apply -f
https://raw.githubusercontent.com/cilium/microscope/1.1.0/docs/microscope.yaml
$ kubectl exec -n kube-system microscope -- microscope -h
More information about Cilium Microscope options can be found on the project homepage: cilium/microscope
Command Reference¶
cilium-agent¶
Run the cilium agent
Options¶
--access-log string Path to access log of supported L7 requests observed
--agent-labels strings Additional labels to identify this agent
--allow-localhost string Policy when to allow local stack to reach local endpoints { auto | always | policy } (default "auto")
--auto-direct-node-routes Enable automatic L2 routing between nodes
--bpf-compile-debug Enable debugging of the BPF compilation process
--bpf-ct-global-any-max int Maximum number of entries in non-TCP CT table (default 262144)
--bpf-ct-global-tcp-max int Maximum number of entries in TCP CT table (default 1000000)
--bpf-ct-timeout-regular-any duration Timeout for entries in non-TCP CT table (default 1m0s)
--bpf-ct-timeout-regular-tcp duration Timeout for established entries in TCP CT table (default 6h0m0s)
--bpf-ct-timeout-regular-tcp-fin duration Teardown timeout for entries in TCP CT table (default 10s)
--bpf-ct-timeout-regular-tcp-syn duration Establishment timeout for entries in TCP CT table (default 1m0s)
--bpf-ct-timeout-service-any duration Timeout for service entries in non-TCP CT table (default 1m0s)
--bpf-ct-timeout-service-tcp duration Timeout for established service entries in TCP CT table (default 6h0m0s)
--bpf-policy-map-max int Maximum number of entries in endpoint policy map (per endpoint) (default 16384)
--bpf-root string Path to BPF filesystem
--cgroup-root string Path to Cgroup2 filesystem
--cluster-id int Unique identifier of the cluster
--cluster-name string Name of the cluster (default "default")
--clustermesh-config string Path to the ClusterMesh configuration directory
--config string Configuration file (default "$HOME/ciliumd.yaml")
--config-dir string Configuration directory that contains a file for each option
--conntrack-gc-interval duration Overwrite the connection-tracking garbage collection interval
--container-runtime strings Sets the container runtime(s) used by Cilium { containerd | crio | docker | none | auto } ( "auto" uses the container runtime found in the order: "docker", "containerd", "crio" ) (default [auto])
--container-runtime-endpoint map Container runtime(s) endpoint(s). (default: --container-runtime-endpoint=containerd=/var/run/containerd/containerd.sock, --container-runtime-endpoint=crio=/var/run/crio/crio.sock, --container-runtime-endpoint=docker=unix:///var/run/docker.sock) (default map[])
--datapath-mode string Datapath mode name (default "veth")
-D, --debug Enable debugging mode
--debug-verbose strings List of enabled verbose debug groups
-d, --device string Device facing cluster/external network for direct L3 (non-overlay mode) (default "undefined")
--disable-conntrack Disable connection tracking
--disable-endpoint-crd Disable use of CiliumEndpoint CRD
--disable-k8s-services Disable east-west K8s load balancing by cilium
-e, --docker string Path to docker runtime socket (DEPRECATED: use container-runtime-endpoint instead) (default "unix:///var/run/docker.sock")
--enable-health-checking Enable connectivity health checking (default true)
--enable-ipsec Enable IPSec support
--enable-ipv4 Enable IPv4 support (default true)
--enable-ipv6 Enable IPv6 support (default true)
--enable-k8s-event-handover Enable k8s event handover to kvstore for improved scalability
--enable-legacy-services Enable legacy (prior-v1.5) services (default true)
--enable-policy string Enable policy enforcement (default "default")
--enable-tracing Enable tracing while determining policy (debugging)
--encrypt-interface string Transparent encryption interface
--endpoint-queue-size int size of EventQueue per-endpoint (default 25)
--envoy-log string Path to a separate Envoy log file, if any
--fixed-identity-mapping map Key-value for the fixed identity mapping which allows to use reserved label for fixed identities (default map[])
--flannel-manage-existing-containers Installs a BPF program to allow for policy enforcement in already running containers managed by Flannel. Require Cilium to be running in the hostPID.
--flannel-master-device string Installs a BPF program to allow for policy enforcement in the given network interface. Allows to run Cilium on top of other CNI plugins that provide networking, e.g. flannel, where for flannel, this value should be set with 'cni0'. [EXPERIMENTAL]
--flannel-uninstall-on-exit When used along the flannel-master-device flag, it cleans up all BPF programs installed when Cilium agent is terminated.
-h, --help help for cilium-agent
--http-idle-timeout uint Time after which a non-gRPC HTTP stream is considered failed unless traffic in the stream has been processed (in seconds); defaults to 0 (unlimited)
--http-max-grpc-timeout uint Time after which a forwarded gRPC request is considered failed unless completed (in seconds). A "grpc-timeout" header may override this with a shorter value; defaults to 0 (unlimited)
--http-request-timeout uint Time after which a forwarded HTTP request is considered failed unless completed (in seconds); Use 0 for unlimited (default 3600)
--http-retry-count uint Number of retries performed after a forwarded request attempt fails (default 3)
--http-retry-timeout uint Time after which a forwarded but uncompleted request is retried (connection failures are retried immediately); defaults to 0 (never)
--identity-change-grace-period duration Time to wait before using new identity on endpoint identity change (default 5s)
--install-iptables-rules Install base iptables rules for cilium to mainly interact with kube-proxy (and masquerading) (default true)
--ipsec-key-file string Path to IPSec key file
--ipv4-cluster-cidr-mask-size int Mask size for the cluster wide CIDR (default 8)
--ipv4-node string IPv4 address of node (default "auto")
--ipv4-range string Per-node IPv4 endpoint prefix, e.g. 10.16.0.0/16 (default "auto")
--ipv4-service-range string Kubernetes IPv4 services CIDR if not inside cluster prefix (default "auto")
--ipv6-cluster-alloc-cidr string IPv6 /64 CIDR used to allocate per node endpoint /96 CIDR (default "f00d::/64")
--ipv6-node string IPv6 address of node (default "auto")
--ipv6-range string Per-node IPv6 endpoint prefix, must be /96, e.g. fd02:1:1::/96 (default "auto")
--ipv6-service-range string Kubernetes IPv6 services CIDR if not inside cluster prefix (default "auto")
--ipvlan-master-device string Device facing external network acting as ipvlan master (default "undefined")
--k8s-api-server string Kubernetes api address server (for https use --k8s-kubeconfig-path instead)
--k8s-kubeconfig-path string Absolute path of the kubernetes kubeconfig file
--k8s-require-ipv4-pod-cidr Require IPv4 PodCIDR to be specified in node resource
--k8s-require-ipv6-pod-cidr Require IPv6 PodCIDR to be specified in node resource
--k8s-watcher-endpoint-selector string K8s endpoint watcher will watch for these k8s endpoints (default "metadata.name!=kube-scheduler,metadata.name!=kube-controller-manager,metadata.name!=etcd-operator,metadata.name!=gcp-controller-manager")
--k8s-watcher-queue-size uint Queue size used to serialize each k8s event type (default 1024)
--keep-bpf-templates Do not restore BPF template files from binary
--keep-config When restoring state, keeps containers' configuration in place
--kvstore string Key-value store type
--kvstore-opt map Key-value store options (default map[])
--kvstore-periodic-sync duration Periodic KVstore synchronization interval (default 5m0s)
--label-prefix-file string Valid label prefixes file path
--labels strings List of label prefixes used to determine identity of an endpoint
--lb string Enables load balancer mode where load balancer bpf program is attached to the given interface
--lib-dir string Directory path to store runtime build environment (default "/var/lib/cilium")
--log-driver strings Logging endpoints to use for example syslog
--log-opt map Log driver options for cilium (default map[])
--log-system-load Enable periodic logging of system load
--masquerade Masquerade packets from endpoints leaving the host (default true)
--metrics strings Metrics that should be enabled or disabled from the default metric list. (+metric_foo to enable metric_foo , -metric_bar to disable metric_bar)
--monitor-aggregation string Level of monitor aggregation for traces from the datapath (default "None")
--monitor-queue-size int Size of the event queue when reading monitor events (default 32768)
--mtu int Overwrite auto-detected MTU of underlying network
--nat46-range string IPv6 prefix to map IPv4 addresses to (default "0:0:0:0:0:FFFF::/96")
--policy-queue-size int size of queues for policy-related events (default 100)
--pprof Enable serving the pprof debugging API
--preallocate-bpf-maps Enable BPF map pre-allocation (default true)
--prefilter-device string Device facing external network for XDP prefiltering (default "undefined")
--prefilter-mode string Prefilter mode { native | generic } (default: native) (default "native")
--prepend-iptables-chains Prepend custom iptables chains instead of appending (default true)
--prometheus-serve-addr string IP:Port on which to serve prometheus metrics (pass ":Port" to bind on all interfaces, "" is off)
--proxy-connect-timeout uint Time after which a TCP connect attempt is considered failed unless completed (in seconds) (default 1)
--restore Restores state, if possible, from previous daemon (default true)
--sidecar-istio-proxy-image string Regular expression matching compatible Istio sidecar istio-proxy container image names (default "cilium/istio_proxy")
--single-cluster-route Use a single cluster route instead of per node routes
--socket-path string Sets daemon's socket path to listen for connections (default "/var/run/cilium/cilium.sock")
--sockops-enable Enable sockops when kernel supported
--state-dir string Directory path to store runtime state (default "/var/run/cilium")
--tofqdns-dns-reject-response-code string DNS response code for rejecting DNS requests, available options are '[nameError refused]' (default "refused")
--tofqdns-enable-poller Enable proactive polling of DNS names in toFQDNs.matchName rules.
--tofqdns-enable-poller-events Emit DNS responses seen by the DNS poller as Monitor events, if the poller is enabled. (default true)
--tofqdns-endpoint-max-ip-per-hostname int Maximum number of IPs to maintain per FQDN name for each endpoint (default 50)
--tofqdns-min-ttl int The minimum time, in seconds, to use DNS data for toFQDNs policies. (default 3600 when --tofqdns-enable-poller, 604800 otherwise)
--tofqdns-pre-cache string DNS cache data at this path is preloaded on agent startup
--tofqdns-proxy-port int Global port on which the in-agent DNS proxy should listen. Default 0 is a OS-assigned port.
--trace-payloadlen int Length of payload to capture when tracing (default 128)
-t, --tunnel string Tunnel mode {vxlan, geneve, disabled} (default "vxlan" for the "veth" datapath mode)
--version Print version information
cilium¶
cilium¶
CLI
Synopsis¶
CLI for interacting with the local Cilium Agent
Options¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-h, --help help for cilium
-H, --host string URI to server-side API
SEE ALSO¶
- cilium bpf - Direct access to local BPF maps
- cilium cleanup - Reset the agent state
- cilium completion - Output shell completion code for bash
- cilium config - Cilium configuration options
- cilium debuginfo - Request available debugging information from agent
- cilium endpoint - Manage endpoints
- cilium fqdn - Manage fqdn proxy
- cilium identity - Manage security identities
- cilium kvstore - Direct access to the kvstore
- cilium map - Access BPF maps
- cilium metrics - Access metric status
- cilium monitor - Display BPF program events
- cilium node - Manage cluster nodes
- cilium policy - Manage security policies
- cilium prefilter - Manage XDP CIDR filters
- cilium preflight - cilium upgrade helper
- cilium service - Manage services & loadbalancers
- cilium status - Display status of daemon
- cilium version - Print version information
cilium bpf¶
Direct access to local BPF maps
Synopsis¶
Direct access to local BPF maps
Options¶
-h, --help help for bpf
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium - CLI
- cilium bpf config - Manage endpoint configuration BPF maps
- cilium bpf ct - Connection tracking tables
- cilium bpf endpoint - Local endpoint map
- cilium bpf ipcache - Manage the IPCache mappings for IP/CIDR <-> Identity
- cilium bpf lb - Load-balancing configuration
- cilium bpf metrics - BPF datapath traffic metrics
- cilium bpf nat - NAT mapping tables
- cilium bpf policy - Manage policy related BPF maps
- cilium bpf proxy - Proxy configuration
- cilium bpf sha - Manage compiled BPF template objects
- cilium bpf tunnel - Tunnel endpoint map
cilium bpf config¶
Manage endpoint configuration BPF maps
Synopsis¶
Manage endpoint configuration BPF maps
Options¶
-h, --help help for config
-o, --output string json| jsonpath='{}'
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium bpf - Direct access to local BPF maps
- cilium bpf config get - List contents of an endpoint config BPF map
cilium bpf config get¶
List contents of an endpoint config BPF map
Options¶
-h, --help help for get
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium bpf config - Manage endpoint configuration BPF maps
cilium bpf ct¶
Connection tracking tables
Synopsis¶
Connection tracking tables
Options¶
-h, --help help for ct
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium bpf - Direct access to local BPF maps
- cilium bpf ct flush - Flush all connection tracking entries
- cilium bpf ct list - List connection tracking entries
cilium bpf ct flush¶
Flush all connection tracking entries
Synopsis¶
Flush all connection tracking entries
cilium bpf ct flush ( <endpoint identifier> | global ) [flags]
Options¶
-h, --help help for flush
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium bpf ct - Connection tracking tables
cilium bpf ct list¶
List connection tracking entries
Synopsis¶
List connection tracking entries
cilium bpf ct list ( <endpoint identifier> | global ) [flags]
Options¶
-h, --help help for list
-o, --output string json| jsonpath='{}'
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium bpf ct - Connection tracking tables
cilium bpf endpoint¶
Local endpoint map
Synopsis¶
Local endpoint map
Options¶
-h, --help help for endpoint
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium bpf - Direct access to local BPF maps
- cilium bpf endpoint delete - Delete local endpoint entries
- cilium bpf endpoint list - List local endpoint entries
cilium bpf endpoint delete¶
Delete local endpoint entries
Options¶
-h, --help help for delete
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium bpf endpoint - Local endpoint map
cilium bpf endpoint list¶
List local endpoint entries
Options¶
-h, --help help for list
-o, --output string json| jsonpath='{}'
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium bpf endpoint - Local endpoint map
cilium bpf ipcache¶
Manage the IPCache mappings for IP/CIDR <-> Identity
Synopsis¶
Manage the IPCache mappings for IP/CIDR <-> Identity
Options¶
-h, --help help for ipcache
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium bpf - Direct access to local BPF maps
- cilium bpf ipcache get - Retrieve identity for an ip
- cilium bpf ipcache list - List endpoint IPs (local and remote) and their corresponding security identities
cilium bpf ipcache get¶
Retrieve identity for an ip
Options¶
-h, --help help for get
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium bpf ipcache - Manage the IPCache mappings for IP/CIDR <-> Identity
cilium bpf ipcache list¶
List endpoint IPs (local and remote) and their corresponding security identities
Synopsis¶
List endpoint IPs (local and remote) and their corresponding security identities.
Note that for Linux kernel versions between 4.11 and 4.15 inclusive, the native LPM map type used for implementing the IPCache does not provide the ability to walk / dump the entries, so on these kernel versions this tool will never return any entries, even if entries exist in the map. You may instead run: cilium map get cilium_ipcache
cilium bpf ipcache list [flags]
Options¶
-h, --help help for list
-o, --output string json| jsonpath='{}'
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium bpf ipcache - Manage the IPCache mappings for IP/CIDR <-> Identity
cilium bpf lb¶
Load-balancing configuration
Synopsis¶
Load-balancing configuration
Options¶
-h, --help help for lb
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium bpf - Direct access to local BPF maps
- cilium bpf lb list - List load-balancing configuration
cilium bpf lb list¶
List load-balancing configuration
Options¶
-h, --help help for list
--legacy List legacy service entries
-o, --output string json| jsonpath='{}'
--revnat List reverse NAT entries
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium bpf lb - Load-balancing configuration
cilium bpf metrics¶
BPF datapath traffic metrics
Synopsis¶
BPF datapath traffic metrics
Options¶
-h, --help help for metrics
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium bpf - Direct access to local BPF maps
- cilium bpf metrics list - List BPF datapath traffic metrics
cilium bpf metrics list¶
List BPF datapath traffic metrics
Options¶
-h, --help help for list
-o, --output string json| jsonpath='{}'
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium bpf metrics - BPF datapath traffic metrics
cilium bpf nat¶
NAT mapping tables
Synopsis¶
NAT mapping tables
Options¶
-h, --help help for nat
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium bpf - Direct access to local BPF maps
- cilium bpf nat flush - Flush all NAT mapping entries
- cilium bpf nat list - List all NAT mapping entries
cilium bpf nat flush¶
Flush all NAT mapping entries
Options¶
-h, --help help for flush
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium bpf nat - NAT mapping tables
cilium bpf nat list¶
List all NAT mapping entries
Options¶
-h, --help help for list
-o, --output string json| jsonpath='{}'
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium bpf nat - NAT mapping tables
cilium bpf policy¶
Manage policy related BPF maps
Synopsis¶
Manage policy related BPF maps
Options¶
-h, --help help for policy
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium bpf - Direct access to local BPF maps
- cilium bpf policy add - Add/update policy entry
- cilium bpf policy delete - Delete a policy entry
- cilium bpf policy get - List contents of a policy BPF map
cilium bpf policy add¶
Add/update policy entry
Synopsis¶
Add/update policy entry
cilium bpf policy add <endpoint id> <traffic-direction> <identity> [port/proto] [flags]
Options¶
-h, --help help for add
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium bpf policy - Manage policy related BPF maps
cilium bpf policy delete¶
Delete a policy entry
Synopsis¶
Delete a policy entry
cilium bpf policy delete <endpoint id> <identity> [port/proto] [flags]
Options¶
-h, --help help for delete
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium bpf policy - Manage policy related BPF maps
cilium bpf policy get¶
List contents of a policy BPF map
Options¶
--all Dump all policy maps
-h, --help help for get
-n, --numeric Do not resolve IDs
-o, --output string json| jsonpath='{}'
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium bpf policy - Manage policy related BPF maps
cilium bpf proxy¶
Proxy configuration
Synopsis¶
Proxy configuration
Options¶
-h, --help help for proxy
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium bpf - Direct access to local BPF maps
- cilium bpf proxy flush - Flush all proxy entries
- cilium bpf proxy list - List proxy configuration
cilium bpf proxy flush¶
Flush all proxy entries
Options¶
-h, --help help for flush
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium bpf proxy - Proxy configuration
cilium bpf proxy list¶
List proxy configuration
Options¶
-h, --help help for list
-o, --output string json| jsonpath='{}'
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium bpf proxy - Proxy configuration
cilium bpf sha¶
Manage compiled BPF template objects
Synopsis¶
Manage compiled BPF template objects
Options¶
-h, --help help for sha
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium bpf - Direct access to local BPF maps
- cilium bpf sha get - Get datapath SHA header
- cilium bpf sha list - List BPF template objects.
cilium bpf sha get¶
Get datapath SHA header
Options¶
-h, --help help for get
-o, --output string json| jsonpath='{}'
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium bpf sha - Manage compiled BPF template objects
cilium bpf sha list¶
List BPF template objects.
Options¶
-h, --help help for list
-o, --output string json| jsonpath='{}'
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium bpf sha - Manage compiled BPF template objects
cilium bpf tunnel¶
Tunnel endpoint map
Synopsis¶
Tunnel endpoint map
Options¶
-h, --help help for tunnel
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium bpf - Direct access to local BPF maps
- cilium bpf tunnel list - List tunnel endpoint entries
cilium bpf tunnel list¶
List tunnel endpoint entries
Options¶
-h, --help help for list
-o, --output string json| jsonpath='{}'
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium bpf tunnel - Tunnel endpoint map
cilium cleanup¶
Reset the agent state
Options¶
-f, --force Skip confirmation
-h, --help help for cleanup
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
cilium completion¶
Output shell completion code for bash
Examples¶
# Installing bash completion on macOS using homebrew
## If running Bash 3.2 included with macOS
brew install bash-completion
## or, if running Bash 4.1+
brew install bash-completion@2
## afterwards you only need to run
cilium completion bash > $(brew --prefix)/etc/bash_completion.d/cilium
# Installing bash completion on Linux
## Load the cilium completion code for bash into the current shell
source <(cilium completion bash)
## Write bash completion code to a file and source if from .bash_profile
cilium completion bash > ~/.cilium/completion.bash.inc
printf "
# Cilium shell completion
source '$HOME/.cilium/completion.bash.inc'
" >> $HOME/.bash_profile
source $HOME/.bash_profile
Options¶
-h, --help help for completion
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
cilium config¶
Cilium configuration options
Options¶
-h, --help help for config
--list-options List available options
-n, --num-pages int Number of pages for perf ring buffer. New values have to be > 0
-o, --output string json| jsonpath='{}'
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
cilium debuginfo¶
Request available debugging information from agent
Options¶
-f, --file Redirect output to file(s)
--file-per-command Generate a single file per command
-h, --help help for debuginfo
--output strings markdown| html| json| jsonpath='{}'
--output-directory string directory for files (if specified will use directory in which this command was ran)
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
cilium endpoint¶
Manage endpoints
Synopsis¶
Manage endpoints
Options¶
-h, --help help for endpoint
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium - CLI
- cilium endpoint config - View & modify endpoint configuration
- cilium endpoint disconnect - Disconnect an endpoint from the network
- cilium endpoint get - Display endpoint information
- cilium endpoint health - View endpoint health
- cilium endpoint labels - Manage label configuration of endpoint
- cilium endpoint list - List all endpoints
- cilium endpoint log - View endpoint status log
- cilium endpoint regenerate - Force regeneration of endpoint program
cilium endpoint config¶
View & modify endpoint configuration
Synopsis¶
View & modify endpoint configuration
cilium endpoint config <endpoint id> [<option>=(enable|disable) ...] [flags]
Examples¶
endpoint config 5421 DropNotification=false TraceNotification=false
Options¶
-h, --help help for config
--list-options List available options
-o, --output string json| jsonpath='{}'
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium endpoint - Manage endpoints
cilium endpoint disconnect¶
Disconnect an endpoint from the network
Options¶
-h, --help help for disconnect
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium endpoint - Manage endpoints
cilium endpoint get¶
Display endpoint information
Synopsis¶
Display endpoint information
cilium endpoint get ( <endpoint identifier> | -l <endpoint labels> ) [flags]
Examples¶
cilium endpoint get 4598, cilium endpoint get pod-name:default:foobar, cilium endpoint get -l id.baz
Options¶
-h, --help help for get
-l, --labels strings list of labels
-o, --output string json| jsonpath='{}'
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium endpoint - Manage endpoints
cilium endpoint health¶
View endpoint health
Examples¶
cilium endpoint health 5421
Options¶
-h, --help help for health
-o, --output string json| jsonpath='{}'
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium endpoint - Manage endpoints
cilium endpoint labels¶
Manage label configuration of endpoint
Options¶
-a, --add strings Add/enable labels
-d, --delete strings Delete/disable labels
-h, --help help for labels
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium endpoint - Manage endpoints
cilium endpoint list¶
List all endpoints
Options¶
-h, --help help for list
--no-headers Do not print headers
-o, --output string json| jsonpath='{}'
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium endpoint - Manage endpoints
cilium endpoint log¶
View endpoint status log
Examples¶
cilium endpoint log 5421
Options¶
-h, --help help for log
-o, --output string json| jsonpath='{}'
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium endpoint - Manage endpoints
cilium endpoint regenerate¶
Force regeneration of endpoint program
Options¶
-h, --help help for regenerate
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium endpoint - Manage endpoints
cilium fqdn¶
Manage fqdn proxy
Options¶
-h, --help help for fqdn
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium - CLI
- cilium fqdn cache - Manage fqdn proxy cache
cilium fqdn cache¶
Manage fqdn proxy cache
Options¶
-h, --help help for cache
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium fqdn - Manage fqdn proxy
- cilium fqdn cache clean - Clean fqdn cache
- cilium fqdn cache list - List fqdn cache contents
cilium fqdn cache clean¶
Clean fqdn cache
Options¶
-f, --force Skip confirmation
-h, --help help for clean
-p, --matchpattern string Delete cache entries with FQDNs that match matchpattern
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium fqdn cache - Manage fqdn proxy cache
cilium fqdn cache list¶
List fqdn cache contents
Options¶
-h, --help help for list
-p, --matchpattern string List cache entries with FQDN that match matchpattern
-o, --output string json| jsonpath='{}'
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium fqdn cache - Manage fqdn proxy cache
cilium identity¶
Manage security identities
Synopsis¶
Manage security identities
Options¶
-h, --help help for identity
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium - CLI
- cilium identity get - Retrieve information about an identity
- cilium identity list - List identities
cilium identity get¶
Retrieve information about an identity
Options¶
-h, --help help for get
--label strings Label to lookup
-o, --output string json| jsonpath='{}'
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium identity - Manage security identities
cilium identity list¶
List identities
Options¶
-h, --help help for list
-o, --output string json| jsonpath='{}'
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium identity - Manage security identities
cilium kvstore¶
Direct access to the kvstore
Synopsis¶
Direct access to the kvstore
Options¶
-h, --help help for kvstore
--kvstore string kvstore type
--kvstore-opt map kvstore options (default map[])
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium - CLI
- cilium kvstore delete - Delete a key
- cilium kvstore get - Retrieve a key
- cilium kvstore set - Set a key and value
cilium kvstore delete¶
Delete a key
Examples¶
cilium kvstore delete --recursive foo
Options¶
-h, --help help for delete
--recursive Recursive lookup
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
--kvstore string kvstore type
--kvstore-opt map kvstore options (default map[])
SEE ALSO¶
- cilium kvstore - Direct access to the kvstore
cilium kvstore get¶
Retrieve a key
Examples¶
cilium kvstore get --recursive foo
Options¶
-h, --help help for get
-o, --output string json| jsonpath='{}'
--recursive Recursive lookup
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
--kvstore string kvstore type
--kvstore-opt map kvstore options (default map[])
SEE ALSO¶
- cilium kvstore - Direct access to the kvstore
cilium kvstore set¶
Set a key and value
Examples¶
cilium kvstore set foo=bar
Options¶
-h, --help help for set
--key string Key
--value string Value
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
--kvstore string kvstore type
--kvstore-opt map kvstore options (default map[])
SEE ALSO¶
- cilium kvstore - Direct access to the kvstore
cilium map¶
Access BPF maps
Synopsis¶
Access BPF maps
Options¶
-h, --help help for map
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium - CLI
- cilium map get - Display BPF map information
- cilium map list - List all open BPF maps
cilium map get¶
Display BPF map information
Examples¶
cilium map get cilium_ipcache
Options¶
-h, --help help for get
-o, --output string json| jsonpath='{}'
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium map - Access BPF maps
cilium map list¶
List all open BPF maps
Examples¶
cilium map list
Options¶
-h, --help help for list
-o, --output string json| jsonpath='{}'
--verbose Print cache contents of all maps
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium map - Access BPF maps
cilium metrics¶
Access metric status
Synopsis¶
Access metric status
Options¶
-h, --help help for metrics
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium - CLI
- cilium metrics list - List all metrics
cilium metrics list¶
List all metrics
Options¶
-h, --help help for list
-o, --output string json| jsonpath='{}'
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium metrics - Access metric status
cilium monitor¶
Display BPF program events
Synopsis¶
The monitor displays notifications and events emitted by the BPF programs attached to endpoints and devices. This includes:
- Dropped packet notifications
- Captured packet traces
- Debugging information
cilium monitor [flags]
Options¶
--from []uint16 Filter by source endpoint id
-h, --help help for monitor
--hex Do not dissect, print payload in HEX
-j, --json Enable json output. Shadows -v flag
--related-to []uint16 Filter by either source or destination endpoint id
--to []uint16 Filter by destination endpoint id
-t, --type []string Filter by event types [agent capture debug drop l7 trace]
-v, --verbose Enable verbose output
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
cilium node¶
Manage cluster nodes
Synopsis¶
Manage cluster nodes
Options¶
-h, --help help for node
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium - CLI
- cilium node list - List nodes
cilium node list¶
List nodes
Options¶
-h, --help help for list
-o, --output string json| jsonpath='{}'
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium node - Manage cluster nodes
cilium policy¶
Manage security policies
Synopsis¶
Manage security policies
Options¶
-h, --help help for policy
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium - CLI
- cilium policy delete - Delete policy rules
- cilium policy get - Display policy node information
- cilium policy import - Import security policy in JSON format
- cilium policy trace - Trace a policy decision
- cilium policy validate - Validate a policy
- cilium policy wait - Wait for all endpoints to have updated to a given policy revision
cilium policy delete¶
Delete policy rules
Options¶
--all Delete all policies
-h, --help help for delete
-o, --output string json| jsonpath='{}'
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium policy - Manage security policies
cilium policy get¶
Display policy node information
Options¶
-h, --help help for get
-o, --output string json| jsonpath='{}'
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium policy - Manage security policies
cilium policy import¶
Import security policy in JSON format
Examples¶
cilium policy import ~/policy.json
cilium policy import ./policies/app/
Options¶
-h, --help help for import
-o, --output string json| jsonpath='{}'
--print Print policy after import
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium policy - Manage security policies
cilium policy trace¶
Trace a policy decision
Synopsis¶
Verifies if the source is allowed to consume destination. Source / destination can be provided as endpoint ID, security ID, Kubernetes Pod, YAML file, set of LABELs. LABEL is represented as SOURCE:KEY[=VALUE]. dports can be can be for example: 80/tcp, 53 or 23/udp. If multiple sources and / or destinations are provided, each source is tested whether there is a policy allowing traffic between it and each destination. –src-k8s-pod and –dst-k8s-pod requires cilium-agent to be running with disable-endpoint-crd option set to “false”.
cilium policy trace ( -s <label context> | --src-identity <security identity> | --src-endpoint <endpoint ID> | --src-k8s-pod <namespace:pod-name> | --src-k8s-yaml <path to YAML file> ) ( -d <label context> | --dst-identity <security identity> | --dst-endpoint <endpoint ID> | --dst-k8s-pod <namespace:pod-name> | --dst-k8s-yaml <path to YAML file>) [--dport <port>[/<protocol>] [flags]
Options¶
--dport strings L4 destination port to search on outgoing traffic of the source label context and on incoming traffic of the destination label context
-d, --dst strings Destination label context
--dst-endpoint string Destination endpoint
--dst-identity int Destination identity (default -1)
--dst-k8s-pod string Destination k8s pod ([namespace:]podname)
--dst-k8s-yaml string Path to YAML file for destination
-h, --help help for trace
-o, --output string json| jsonpath='{}'
-s, --src strings Source label context
--src-endpoint string Source endpoint
--src-identity int Source identity (default -1)
--src-k8s-pod string Source k8s pod ([namespace:]podname)
--src-k8s-yaml string Path to YAML file for source
-v, --verbose Set tracing to TRACE_VERBOSE
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium policy - Manage security policies
cilium policy validate¶
Validate a policy
Options¶
-h, --help help for validate
--print Print policy after validation
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium policy - Manage security policies
cilium policy wait¶
Wait for all endpoints to have updated to a given policy revision
Synopsis¶
Wait for all endpoints to have updated to a given policy revision
cilium policy wait <revision> [flags]
Options¶
--fail-wait-time int Wait time after which command fails if endpoint regeration fails (seconds) (default 60)
-h, --help help for wait
--max-wait-time int Wait time after which command fails (seconds) (default 360)
--sleep-time int Sleep interval between checks (seconds) (default 1)
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium policy - Manage security policies
cilium prefilter¶
Manage XDP CIDR filters
Synopsis¶
Manage XDP CIDR filters
Options¶
-h, --help help for prefilter
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium - CLI
- cilium prefilter delete - Delete CIDR filters
- cilium prefilter list - List CIDR filters
- cilium prefilter update - Update CIDR filters
cilium prefilter delete¶
Delete CIDR filters
Options¶
--cidr strings List of CIDR prefixes to delete
-h, --help help for delete
--revision uint Update revision
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium prefilter - Manage XDP CIDR filters
cilium prefilter list¶
List CIDR filters
Options¶
-h, --help help for list
-o, --output string json| jsonpath='{}'
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium prefilter - Manage XDP CIDR filters
cilium prefilter update¶
Update CIDR filters
Options¶
--cidr strings List of CIDR prefixes to block
-h, --help help for update
--revision uint Update revision
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium prefilter - Manage XDP CIDR filters
cilium preflight¶
cilium upgrade helper
Synopsis¶
CLI to help upgrade cilium
Options¶
-h, --help help for preflight
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium - CLI
- cilium preflight fqdn-poller - Prepare for DNS Polling upgrades to cilium 1.4
cilium preflight fqdn-poller¶
Prepare for DNS Polling upgrades to cilium 1.4
Synopsis¶
Prepare for DNS Polling upgrades to cilium 1.4 by creating a placeholder –tofqdns-pre-cache file that can be used to pre-seed the DNS cached used in toFQDNs rules. This is useful when upgrading cilium with DNS Polling policies where an interruption in allowed IPs is undesirable. It may also be used when switching from DNS Polling based DNS discovery to DNS Proxy based discovery where an endpoint may not make a DNS request soon enough to be used by toFQDNs policy rules
cilium preflight fqdn-poller [flags]
Options¶
-h, --help help for fqdn-poller
--tofqdns-pre-cache string The path to write serialized ToFQDNs pre-cache information. stdout is the default
--tofqdns-pre-cache-ttl int TTL, in seconds, to set on generated ToFQDNs pre-cache information (default 604800)
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium preflight - cilium upgrade helper
cilium service¶
Manage services & loadbalancers
Synopsis¶
Manage services & loadbalancers
Options¶
-h, --help help for service
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium - CLI
- cilium service delete - Delete a service
- cilium service get - Display service information
- cilium service list - List services
- cilium service update - Update a service
cilium service delete¶
Delete a service
Options¶
--all Delete all services
-h, --help help for delete
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium service - Manage services & loadbalancers
cilium service get¶
Display service information
Options¶
-h, --help help for get
-o, --output string json| jsonpath='{}'
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium service - Manage services & loadbalancers
cilium service list¶
List services
Options¶
-h, --help help for list
-o, --output string json| jsonpath='{}'
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium service - Manage services & loadbalancers
cilium service update¶
Update a service
Options¶
--backends strings Backend address or addresses followed by optional weight (<IP:Port>[/weight])
--frontend string Frontend address
-h, --help help for update
--id uint Identifier
--rev Add reverse translation (default true)
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
SEE ALSO¶
- cilium service - Manage services & loadbalancers
cilium status¶
Display status of daemon
Options¶
--all-addresses Show all allocated addresses, not just count
--all-controllers Show all controllers, not just failing
--all-health Show all health status, not just failing
--all-nodes Show all nodes, not just localhost
--all-redirects Show all redirects
--brief Only print a one-line status message
-h, --help help for status
-o, --output string json| jsonpath='{}'
--verbose Equivalent to --all-addresses --all-controllers --all-nodes --all-health
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
cilium version¶
Print version information
Options¶
-h, --help help for version
-o, --output string json| jsonpath='{}'
Options inherited from parent commands¶
--config string config file (default is $HOME/.cilium.yaml)
-D, --debug Enable debug messages
-H, --host string URI to server-side API
cilium-bugtool¶
Collects agent & system information useful for bug reporting
Synopsis¶
Collects agent & system information useful for bug reporting
cilium-bugtool [OPTIONS] [flags]
Examples¶
# Collect information and create archive file
$ cilium-bugtool
[...]
# Collect and retrieve archive if Cilium is running in a Kubernetes pod
$ kubectl get pods --namespace kube-system
NAME READY STATUS RESTARTS AGE
cilium-kg8lv 1/1 Running 0 13m
[...]
$ kubectl -n kube-system exec cilium-kg8lv cilium-bugtool
$ kubectl cp kube-system/cilium-kg8lv:/tmp/cilium-bugtool-243785589.tar /tmp/cilium-bugtool-243785589.tar
Options¶
--archive Create archive when false skips deletion of the output directory (default true)
--archive-prefix string String to prefix to name of archive if created (e.g., with cilium pod-name)
-o, --archiveType string Archive type: tar | gz (default "tar")
--config string Configuration to decide what should be run (default "./.cilium-bugtool.config")
--dry-run Create configuration file of all commands that would have been executed
--enable-markdown Dump output of commands in markdown format
--exec-timeout duration The default timeout for any cmd execution in seconds (default 30s)
-h, --help help for cilium-bugtool
-H, --host string URI to server-side API
--k8s-label string Kubernetes label for Cilium pod (default "k8s-app=cilium")
--k8s-mode Require Kubernetes pods to be found or fail
--k8s-namespace string Kubernetes namespace for Cilium pod (default "kube-system")
-t, --tmp string Path to store extracted files (default "/tmp")
cilium-health get¶
Display local cilium agent status
Options¶
-h, --help help for get
-o, --output string json| jsonpath='{}'
Options inherited from parent commands¶
--admin string Expose resources over 'unix' socket, 'any' socket (default "unix")
-c, --cilium string URI to Cilium server API
-d, --daemon Run as a daemon
-D, --debug Enable debug messages
-H, --host string URI to cilium-health server API
-i, --interval uint Interval (in seconds) for periodic connectivity probes (default 60)
--log-driver strings Logging endpoints to use for example syslog
--log-opt map Log driver options for cilium-health (default map[])
-p, --passive Only respond to HTTP health checks
--pidfile string Write the PID to the specified file
SEE ALSO¶
- cilium-health - Cilium Health Agent
cilium-health ping¶
Check whether the cilium-health API is up
Options¶
-h, --help help for ping
Options inherited from parent commands¶
--admin string Expose resources over 'unix' socket, 'any' socket (default "unix")
-c, --cilium string URI to Cilium server API
-d, --daemon Run as a daemon
-D, --debug Enable debug messages
-H, --host string URI to cilium-health server API
-i, --interval uint Interval (in seconds) for periodic connectivity probes (default 60)
--log-driver strings Logging endpoints to use for example syslog
--log-opt map Log driver options for cilium-health (default map[])
-p, --passive Only respond to HTTP health checks
--pidfile string Write the PID to the specified file
SEE ALSO¶
- cilium-health - Cilium Health Agent
cilium-health status¶
Display cilium connectivity to other nodes
Options¶
-h, --help help for status
-o, --output string json| jsonpath='{}'
--probe Synchronously probe connectivity status
--succinct Print the result succinctly (one node per line)
--verbose Print more information in results
Options inherited from parent commands¶
--admin string Expose resources over 'unix' socket, 'any' socket (default "unix")
-c, --cilium string URI to Cilium server API
-d, --daemon Run as a daemon
-D, --debug Enable debug messages
-H, --host string URI to cilium-health server API
-i, --interval uint Interval (in seconds) for periodic connectivity probes (default 60)
--log-driver strings Logging endpoints to use for example syslog
--log-opt map Log driver options for cilium-health (default map[])
-p, --passive Only respond to HTTP health checks
--pidfile string Write the PID to the specified file
SEE ALSO¶
- cilium-health - Cilium Health Agent
cilium-health¶
Cilium Health Agent
Options¶
--admin string Expose resources over 'unix' socket, 'any' socket (default "unix")
-c, --cilium string URI to Cilium server API
-d, --daemon Run as a daemon
-D, --debug Enable debug messages
-h, --help help for cilium-health
-H, --host string URI to cilium-health server API
-i, --interval uint Interval (in seconds) for periodic connectivity probes (default 60)
--log-driver strings Logging endpoints to use for example syslog
--log-opt map Log driver options for cilium-health (default map[])
-p, --passive Only respond to HTTP health checks
--pidfile string Write the PID to the specified file
SEE ALSO¶
- cilium-health get - Display local cilium agent status
- cilium-health ping - Check whether the cilium-health API is up
- cilium-health status - Display cilium connectivity to other nodes
Key-Value Store¶
| Option | Description | Default |
| –kvstore TYPE | Key Value Store Type: (consul, etcd) | |
| –kvstore-opt OPTS |
consul¶
When using consul, the consul agent address needs to be provided with the
consul.address: consul.tlsconfig is optional, and is only required
for TLS authentication:
| Option | Type | Description |
| consul.address | Address | Address of consul agent |
| consul.tlsconfig | Path | Path to a consul configuration file for client server authentication |
Example of the consul configuration file:
---
cafile: '/var/lib/cilium/consul-ca.pem'
keyfile: '/var/lib/cilium/client-key.pem'
certfile: '/var/lib/cilium/client.pem'
#insecureskipverify: true
etcd¶
When using etcd, one of the following options need to be provided to configure the etcd endpoints:
| Option | Type | Description |
| etcd.address | Address | Address of etcd endpoint |
| etcd.config | Path | Path to an etcd configuration file. |
Example of the etcd configuration file:
---
endpoints:
- https://192.168.0.1:2379
- https://192.168.0.2:2379
ca-file: '/var/lib/cilium/etcd-ca.pem'
# In case you want client to server authentication
key-file: '/var/lib/cilium/etcd-client.key'
cert-file: '/var/lib/cilium/etcd-client.crt'
Key-Value Store¶
Cilium uses an external key-value store to exchange information across multiple Cilium instances:
Layout¶
All data is stored under a common key prefix:
| Prefix | Description |
|---|---|
cilium/ |
All keys share this common prefix. |
cilium/state/ |
State stored by agents, data is automatically recreated on removal or corruption. |
Cluster Nodes¶
Every agent will register itself as a node in the kvstore and make the following information available to other agents:
- Name
- IP addresses of the node
- Health checking IP addresses
- Allocation range of endpoints on the node
| Key | Value |
|---|---|
cilium/state/nodes/v1/<cluster>/<node> |
node.Node |
All node keys are attached to a lease owned by the agent of the respective node.
Services¶
All Kubernetes services are mirrored into the kvstore by the Cilium operator. This is required to implement multi cluster service discovery.
| Key | Value |
|---|---|
cilium/state/services/v1/<cluster>/<namespace>/<service> |
service.ClusterService |
Identities¶
Any time a new endpoint is started on a Cilium node, it will determine whether the labels for the endpoint are unique and allocate an identity for that set of labels. These identities are only meaningful within the local cluster.
| Key | Value |
|---|---|
cilium/state/identities/v1/id/<identity> |
labels.LabelArray |
cilium/state/identities/v1/value/<labels>/<node> |
identity.NumericIdentity |
Endpoints¶
All endpoint IPs and corresponding identities are mirrored to the kvstore by the agent on the node where the endpoint is launched, to allow peer nodes to configure egress policies to endpoints backed by these IPs.
| Key | Value |
|---|---|
cilium/state/ip/v1/<cluster>/<ip> |
identity.IPIdentityPair |
Leases¶
With a few exceptions, all keys in the key-value store are owned by a particular agent running on a node. All such keys have a lease attached. The lease is renewed automatically. When the lease expires, the key is removed from the key-value store. This guarantees that keys are removed from the key-value store in the event that an agent dies on a particular and never reappears.
The lease lifetime is set to 15 minutes. The exact expiration behavior is dependent on the kvstore implementation but the expiration typically occurs after double the lifetime
Debugging¶
The contents stored in the kvstore can be queued and manipulate using the
cilium kvstore command. For additional details, see the command reference.
Example:
$ cilium kvstore get --recursive cilium/state/nodes/
cilium/state/nodes/v1/default/runtime1 => {"Name":"runtime1","IPAddresses":[{"AddressType":"InternalIP","IP":"10.0.2.15"}],"IPv4AllocCIDR":{"IP":"10.11.0.0","Mask":"//8AAA=="},"IPv6AllocCIDR":{"IP":"f00d::a0f:0:0:0","Mask":"//////////////////8AAA=="},"IPv4HealthIP":"","IPv6HealthIP":""}
Further Reading¶
Presentations¶
- DockerCon, Austin TX, Apr 2017 - Cilium - Network and Application Security with BPF and XDP: Slides, Video
- CNCF/KubeCon Meetup, Berlin, Mar 2017 - Linux Native, HTTP Aware Network Security: Slides, Video
- Docker Distributed Systems Summit, Berlin, Oct 2016: Slides, Video
- NetDev1.2, Tokyo, Sep 2016 - cls_bpf/eBPF updates since netdev 1.1: Slides, Video
- NetDev1.2, Tokyo, Sep 2016 - Advanced programmability and recent updates with tc’s cls_bpf: Slides, Video
- ContainerCon NA, Toronto, Aug 2016 - Fast IPv6 container networking with BPF & XDP: Slides
Podcasts¶
Glossary¶
Cilium has some terms with special meanings. These should all be covered throughout the documentation but for convenience we have also listed some of them below with short descriptions. If you need more information, please ask us on Slack. Feel free to extend this document with words you expected to see here.
- CNI
- https://github.com/containernetworking/cni
- ConfigMap
- https://kubernetes.io/docs/tasks/configure-pod-container/configure-pod-configmap/
- CustomResourceDefinition
- https://kubernetes.io/docs/concepts/api-extension/custom-resources/#customresourcedefinitions
- DaemonSet
- https://kubernetes.io/docs/admin/daemons/
- Endpoint
- Endpoint
- Geneve
- https://tools.ietf.org/html/draft-ietf-nvo3-geneve-04
- HeadlessServices
- https://kubernetes.io/docs/concepts/services-networking/service/#headless-services
- iproute2
- https://www.kernel.org/pub/linux/utils/net/iproute2/
- Linux kernel
- https://www.kernel.org/
- llvm
- http://releases.llvm.org/
- NodeSelector
- https://kubernetes.io/docs/concepts/configuration/assign-pod-node/
- Pod
- Pods
- https://kubernetes.io/docs/concepts/workloads/pods/pod/
- Policy
- A Cilium policy consists of a list of rules. The security policy can be specified in The Kubernetes NetworkPolicy format or The Cilium policy language.
- RBAC
- https://kubernetes.io/docs/admin/authorization/rbac/
- Slack channel
- Public community slack channel for everyone to ask questions https://cilium.herokuapp.com
- Volumes
- https://kubernetes.io/docs/tasks/configure-pod-container/configure-volume-storage/
- VXLAN
- https://tools.ietf.org/html/rfc7348