# Using NFS VM when deploying NFS provisioner for Kubernetes

# Prerequisites

• Configure the variables described in the section Kubernetes Persistent Volume configuration
• Install the kubectl binary on your Ansible box
• Install the UCP Client bundle for the admin user
• Confirm that you can connect to the cluster by running a test command, for example, kubectl get nodes

# Configurating NFS VM for post-deployment verification

In this example, it is assumed that the relevant variables are configured as follows:

In this instance, the variable nfs_external_server is commented out, resulting in the NFS VM being used, rather than any external server.

Note: When using an external NFS server such as the one hosted by 3PAR, you need to create the file shares manually as shown in the previous section. If you are using the NFS VM, the file share is created automatically when running site.yml by the playbook playbooks/install_nfs_server.yml. If you wish to change the file share after initial deployment, you must update the variable nfs_provisioner_server_share and then re-run the playbook playbooks/install_nfs_server.yml.

# Running the playbook

Once the prerequisites are satisfied, run the appropriate playbook on your Ansible node:

# cd ~/Docker-Synergy
# ansible-playbook -i hosts playbooks/nfs-provisioner.yml --vault-password-file .vault_pass

Running the command kubectl get sc will show the storage class named nfs-vm:

# kubectl get sc

NAME      PROVISIONER   AGE
nfs-vm     hpe.com/nfs-vm     5m

The playbook has a built-in test to validate the provisioining. A pod is deployed to write some test content:

templates/nfs-provisioner/nfs-provisioner-writer-pod.yml.j2

kind: Pod
apiVersion: v1
metadata:
  name: writer-pod
spec:
  containers:
  - name: writer-pod
    image: gcr.io/google_containers/busybox:1.24
    command:
      - "/bin/sh"
    args:
      - "-c"
      - "echo '{{ TestMessage }}' >/mnt/bar.txt && while [ 1 ] ; do sleep 2 ; done "
    volumeMounts:
      - name: nfs-pvc
        mountPath: "/mnt"
  restartPolicy: "Never"
  volumes:
    - name: nfs-pvc
      persistentVolumeClaim:
        claimName: test-claim

This pod is then deleted, and a new pod is deployed to check that the test content has been persisted after the writer pod went away.

templates/nfs-provisioner/nfs-provisioner-reader-pod.yml.j2

kind: Pod
apiVersion: v1
metadata:
  name: reader-pod
spec:
  containers:
  - name: reader-pod
    image: gcr.io/google_containers/busybox:1.24
    command:
      - "/bin/sh"
    args:
      - "-c"
      - "cat /mnt/bar.txt  && while [ 1 ] ; do sleep 1 ; done "
    volumeMounts:
      - name: nfs-pvc
        mountPath: "/mnt"
  restartPolicy: "Never"
  volumes:
    - name: nfs-pvc
      persistentVolumeClaim:
        claimName: test-claim

You should see the following output if the provisioning succeeds:

ok: [localhost] => {
    "msg": "Successfully tested NFS persistent storage"
}