Use Cilium for NetworkPolicy
This page shows how to use Cilium for NetworkPolicy.
For background on Cilium, read the Introduction to Cilium.
- Before you begin
- Deploying Cilium on Minikube for Basic Testing
- Deploying Cilium for Production Use
- Understanding Cilium components
- What’s next
Before you begin
You need to have a Kubernetes cluster, and the kubectl command-line tool must be configured to communicate with your cluster. If you do not already have a cluster, you can create one by using Minikube, or you can use one of these Kubernetes playgrounds:
Deploying Cilium on Minikube for Basic Testing
To get familiar with Cilium easily you can follow the Cilium Kubernetes Getting Started Guide to perform a basic DaemonSet installation of Cilium in minikube.
Installation in a minikube setup uses a simple ‘‘all-in-one’’ YAML file that includes DaemonSet configurations for Cilium and a key-value store (consul) as well as appropriate RBAC settings:
$ kubectl create -f https://raw.githubusercontent.com/cilium/cilium/master/examples/minikube/cilium-ds.yaml
clusterrole "cilium" created
serviceaccount "cilium" created
clusterrolebinding "cilium" created
daemonset "cilium-consul" created
daemonset "cilium" created
The remainder of the Getting Started Guide explains how to enforce both L3/L4 (i.e., IP address + port) security policies, as well as L7 (e.g., HTTP) security policies using an example application.
Deploying Cilium for Production Use
For detailed instructions around deploying Cilium for production, see: Cilium Administrator Guide This documentation includes detailed requirements, instructions and example production DaemonSet files.
Understanding Cilium components
Deploying a cluster with Cilium adds Pods to the kube-system namespace. To see this list of Pods run:
kubectl get pods --namespace=kube-system
You’ll see a list of Pods similar to this:
NAME DESIRED CURRENT READY NODE-SELECTOR AGE
cilium 1 1 1 <none> 2m
...
There are two main components to be aware of:
- One
ciliumPod runs on each node in your cluster and enforces network policy on the traffic to/from Pods on that node using Linux BPF. - For production deployments, Cilium should leverage the key-value store cluster (e.g., etcd) used by Kubernetes, which typically runs on the Kubernetes master nodes. The Cilium Administrator Guide includes an example DaemonSet which can be customized to point to this key-value store cluster. The simple ‘‘all-in-one’’ DaemonSet for minikube requires no such configuration because it automatically deploys a
cilium-consulPod to provide a key-value store.
What’s next
Once your cluster is running, you can follow the NetworkPolicy getting started guide to try out Kubernetes NetworkPolicy with Cilium. Have fun, and if you have questions, contact us using the Cilium Slack Channel.