Read-only folder to be shared to another pod

Question

I have a pod that needs to create a lot of jobs. I'd like to share a read-only folder. How can I do it?

Several ideas I can imagine (I'm newbie to Kubernetes):

• Ephemeral volumes seem a good choice, but I've read it cannot be shared with another pod.
• I thihk NFS is an overkill, too much for my needs.
• Maybe, I could build a data only Docker image, but this is a deprecated feature of Docker.
• kubectl cp to copy the data between the base pod to the pod in the job.

What would be the better solution for this?

Answer 1

You can use a PersistentVolume and mount it as read only volume inside the pod via PersistentVolumeClaim. To mount a read only volume, set .spec.containers[*].volumeMounts[*].readOnly to true.

apiVersion: v1
kind: Pod
metadata:
  name: mypod
spec:
  containers:
    - name: myfrontend
      image: nginx
      volumeMounts:
      - mountPath: "/var/www/html"
        name: mypd
        readOnly: true
  volumes:
    - name: mypd
      persistentVolumeClaim:
        claimName: myclaim

Check out these links:

1. https://kubernetes.io/docs/concepts/storage/persistent-volumes/#persistentvolumeclaims
2. https://kubernetes.io/docs/concepts/storage/persistent-volumes/#persistent-volumes