Configure a Pod to Use a Projected Volume for Storage

This page shows how to use a projected Volume to mount several existing volume sources into the same directory. Currently, secret, configMap, downwardAPI, and serviceAccountToken volumes can be projected.

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:

• Killercoda
• Play with Kubernetes

Configure a projected volume for a pod

In this exercise, you create username and password Secrets from local files. You then create a Pod that runs one container, using a projected Volume to mount the Secrets into the same shared directory.

Here is the configuration file for the Pod:

pods/storage/projected.yaml

apiVersion:v1kind:Podmetadata:name:test-projected-volumespec:containers:- name:test-projected-volumeimage:busybox:1.28args:- sleep- "86400"volumeMounts:- name:all-in-onemountPath:"/projected-volume"readOnly:truevolumes:- name:all-in-oneprojected:sources:- secret:name:user- secret:name:pass

1. Create the Secrets:

   # Create files containing the username and password:echo -n "admin" > ./username.txt echo -n "1f2d1e2e67df" > ./password.txt # Package these files into secrets:kubectl create secret generic user --from-file=./username.txt kubectl create secret generic pass --from-file=./password.txt 

2. Create the Pod:

   kubectl apply -f https://k8s.io/examples/pods/storage/projected.yaml 

3. Verify that the Pod's container is running, and then watch for changes to the Pod:

   kubectl get --watch pod test-projected-volume 

   The output looks like this:

   NAME READY STATUS RESTARTS AGE test-projected-volume 1/1 Running 0 14s 

4. In another terminal, get a shell to the running container:

   kubectl exec -it test-projected-volume -- /bin/sh 

5. In your shell, verify that the projected-volume directory contains your projected sources:

   ls /projected-volume/ 

Clean up

Delete the Pod and the Secrets:

kubectl delete pod test-projected-volume kubectl delete secret user pass 

What's next

• Learn more about projected volumes.
• Read the all-in-one volume design document.