website/docs/tasks/administer-cluster/cilium-network-policy.md

approvers	title
danwent	Use Cilium for NetworkPolicy

{% capture overview %} This page shows how to use Cilium for NetworkPolicy.

For background on Cilium, read the Introduction to Cilium. {% endcapture %}

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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.

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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 cilium Pod 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-consul Pod to provide a key-value store.

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{% capture whatsnext %} Once your cluster is running, you can follow the Declare Network Policy to try out Kubernetes NetworkPolicy with Cilium. Have fun, and if you have questions, contact us using the Cilium Slack Channel. {% endcapture %}

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