--- title: Configure Pod Initialization content_template: templates/task weight: 130 --- {{% capture overview %}} This page shows how to use an Init Container to initialize a Pod before an application Container runs. {{% /capture %}} {{% capture prerequisites %}} {{< include "task-tutorial-prereqs.md" >}} {{< version-check >}} {{% /capture %}} {{% capture steps %}} ## Create a Pod that has an Init Container In this exercise you create a Pod that has one application Container and one Init Container. The init container runs to completion before the application container starts. Here is the configuration file for the Pod: {{< code file="init-containers.yaml" >}} In the configuration file, you can see that the Pod has a Volume that the init container and the application container share. The init container mounts the shared Volume at `/work-dir`, and the application container mounts the shared Volume at `/usr/share/nginx/html`. The init container runs the following command and then terminates: wget -O /work-dir/index.html http://kubernetes.io Notice that the init container writes the `index.html` file in the root directory of the nginx server. Create the Pod: kubectl create -f https://k8s.io/docs/tasks/configure-pod-container/init-containers.yaml Verify that the nginx container is running: kubectl get pod init-demo The output shows that the nginx container is running: NAME READY STATUS RESTARTS AGE init-demo 1/1 Running 0 1m Get a shell into the nginx container running in the init-demo Pod: kubectl exec -it init-demo -- /bin/bash In your shell, send a GET request to the nginx server: root@nginx:~# apt-get update root@nginx:~# apt-get install curl root@nginx:~# curl localhost The output shows that nginx is serving the web page that was written by the init container: ... "url": "http://kubernetes.io/"} ...

Kubernetes is open source giving you the freedom to take advantage ...

... {{% /capture %}} {{% capture whatsnext %}} * Learn more about [communicating between Containers running in the same Pod](/docs/tasks/access-application-cluster/communicate-containers-same-pod-shared-volume/). * Learn more about [Init Containers](/docs/concepts/workloads/pods/init-containers/). * Learn more about [Volumes](/docs/concepts/storage/volumes/). * Learn more about [Debugging Init Containers](/docs/tasks/debug-application-cluster/debug-init-containers/) {{% /capture %}}