# Configure Pod Initialization LLMS index: [llms.txt](/llms.txt) --- This page shows how to use an Init Container to initialize a Pod before an application Container runs. ## Before you begin

You need to have a Kubernetes cluster, and the kubectl command-line tool must be configured to communicate with your cluster. It is recommended to run this tutorial on a cluster with at least two nodes that are not acting as control plane hosts. If you do not already have a cluster, you can create one by using minikube or you can use one of these Kubernetes playgrounds:

To check the version, enter kubectl version.

## 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:

    pods/init-containers.yaml
    
apiVersion: v1
kind: Pod
metadata:
  name: init-demo
spec:
  containers:
  - name: nginx
    image: nginx
    ports:
    - containerPort: 80
    volumeMounts:
    - name: workdir
      mountPath: /usr/share/nginx/html
  # These containers are run during pod initialization
  initContainers:
  - name: install
    image: busybox:1.28
    command:
    - wget
    - "-O"
    - "/work-dir/index.html"
    - http://info.cern.ch
    volumeMounts:
    - name: workdir
      mountPath: "/work-dir"
  dnsPolicy: Default
  volumes:
  - name: workdir
    emptyDir: {}

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

http://info.cern.ch

http://info.cern.ch - home of the first website

...

Browse the first website

... ``` ## What's next * 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/)