Declare Network Policy in Kubernetes

--- reviewers: - caseydavenport - danwinship title: Declare Network Policy min-kubernetes-server-version: v1.8 content_type: task weight: 180 ---  This document helps you get started using the Kubernetes [NetworkPolicy API](/docs/concepts/services-networking/network-policies/) to declare network policies that govern how pods communicate with each other. {{% thirdparty-content %}} ## {{% heading "prerequisites" %}} {{< include "task-tutorial-prereqs.md" >}} {{< version-check >}} Make sure you've configured a network provider with network policy support. There are a number of network providers that support NetworkPolicy, including: * [Antrea](/docs/tasks/administer-cluster/network-policy-provider/antrea-network-policy/) * [Calico](/docs/tasks/administer-cluster/network-policy-provider/calico-network-policy/) * [Cilium](/docs/tasks/administer-cluster/network-policy-provider/cilium-network-policy/) * [Kube-router](/docs/tasks/administer-cluster/network-policy-provider/kube-router-network-policy/) * [Romana](/docs/tasks/administer-cluster/network-policy-provider/romana-network-policy/) * [Weave Net](/docs/tasks/administer-cluster/network-policy-provider/weave-network-policy/)  ## Create an `nginx` deployment and expose it via a service To see how Kubernetes network policy works, start off by creating an `nginx` Deployment. ```console kubectl create deployment nginx --image=nginx ``` ```none deployment.apps/nginx created ``` Expose the Deployment through a Service called `nginx`. ```console kubectl expose deployment nginx --port=80 ``` ```none service/nginx exposed ``` The above commands create a Deployment with an nginx Pod and expose the Deployment through a Service named `nginx`. The `nginx` Pod and Deployment are found in the `default` namespace. ```console kubectl get svc,pod ``` ```none NAME CLUSTER-IP EXTERNAL-IP PORT(S) AGE service/kubernetes 10.100.0.1 <none> 443/TCP 46m service/nginx 10.100.0.16 <none> 80/TCP 33s NAME READY STATUS RESTARTS AGE pod/nginx-701339712-e0qfq 1/1 Running 0 35s ```

This document guides you through using Kubernetes NetworkPolicy API to control pod-to-pod communication. It begins by outlining the prerequisites, including having a network provider with NetworkPolicy support. It then walks through creating an nginx deployment and exposing it via a service to demonstrate how network policies work.