Let's explore persistent volumes (PVs):

1. In our case, run the following describe nodes command: 

kc describe nodes

The preceding command gives the following output:

  Namespace Name  CPU Requests  CPU Limits  Memory Requests  Memory Limits
  default   handsonaks-wp-mariadb-0                     0 (0%)        0 (0%)      0 (0%)           0 (0%)
  default   handsonaks-wp-wordpress-6ddcfd5c89-p2925    300m (31%)    0 (0%)      512Mi (38%)      0 (0%)

2. Are all pods on agent-0? Your pod placement may vary. To verify this run the following command:

ab443838-9b3e-4811-b287-74e417a9@Azure:~$ kc get pvc
NAME                  STATUS    VOLUME                 CAPACITY   ACCESS MODES   STORAGECLASS   AGE
data-handsonaks-wp-mariadb-0   Bound pvc-752cea13-0c73-11e9-9914-82000ff4ac53   8Gi RWO  default 1h
handsonaks-wp-wordpress        Bound pvc-74f785bc-0c73-11e9-9914-82000ff4ac53  10Gi  RWO default 1h

The following command shows the PVCs that are bound to the pods:

kc get pv # the actual persistent volumes
...
Type:         AzureDisk (an Azure Data Disk mount on the host and bind mount to the pod)
    DiskName:     kubernetes-dynamic-pvc-74f785bc-0c73-11e9-9914-82000ff4ac53
    DiskURI:      /subscriptions/12736543-b466-490b-88c6-f1136a239821/resourceGroups/MC_cloud-shell-storage-westus_myhandsonaks_westus2/providers/Microsoft.Compute/disks/kubernetes-dynamic-pvc-74f785bc-0c73-11e9-9914-82000ff4ac53
...
# shows the actual disk backing up the PVC

3. Verify that your site is actually working:

ab443838-9b3e-4811-b287-74e417a9@Azure:~$ kc get svc
NAME                      TYPE           CLUSTER-IP    EXTERNAL-IP   PORT(S)                      AGE
handsonaks-wp-wordpress   LoadBalancer   10.0.78.128   <EXTERNAL-IP>   80:31425/TCP,443:31446/TCP   1h

4. Log on to the site (using the Log In link) as follows:

helm status handsonaks-wp
echo Password: $(kubectl get secret --namespace default handsonaks-wp-wordpress -o jsonpath="{.data.wordpress-password}" | base64 --decode)

5. Add a test post and click on Post Comment to publish it:

We will verify whether this post survives a reboot in the next section.