Configure Pod Initialization
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 .
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:
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:
The output shows that the nginx container is running:
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:
The output shows that nginx is serving the web page that was written by the init container:
<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 .
- Learn more about Init Containers.
- Learn more about .
- Learn more about Debugging Init Containers