Configure Pod Initialization [page]deterministic
This page shows how to use an Init Container to initialize a Pod before an application Container runs.
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## 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:
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:
```shell wget -O /work-dir/index.html http://info.cern.ch ```
Notice that the init container writes the `index.html` file in the root directory of the nginx server.
Create the Pod:
```shell kubectl apply -f https://k8s.io/examples/pods/init-containers.yaml ```
Verify that the nginx container is running:
```shell 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:
```shell 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:
```html <html><head></head><body><header> <title>http://info.cern.ch</title> </header>
<h1>http://info.cern.ch - home of the first website</h1> ... <li><a href="http://info.cern.ch/hypertext/WWW/TheProject.html">Browse the first website</a></li> ... ```
##
* 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/debug-application/debug-init-containers/)