Scenario

The cluster has no StorageClass configured for dynamic volume expansion.

Task

Create a StorageClass with volume expansion enabled, create a PVC and Pod using it, then expand the PVC from 1Gi to 2Gi.

Resource templates are available at /home/interview/.

Step 1: Edit StorageClass template storageclass.yaml:

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: fast-sc                      # Fix: my-storage -> fast-sc
provisioner: rancher.io/local-path
allowVolumeExpansion: true           # Fix: false -> true
volumeBindingMode: WaitForFirstConsumer

kubectl apply -f /home/interview/storageclass.yaml

Step 2: Edit PVC template pvc.yaml:

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: expand-pvc                   # Fix: my-pvc -> expand-pvc
  namespace: storage                 # Fix: default -> storage
spec:
  accessModes:
    - ReadWriteOnce
  storageClassName: fast-sc          # Fix: standard -> fast-sc
  resources:
    requests:
      storage: 1Gi                   # Fix: 500Mi -> 1Gi

kubectl apply -f /home/interview/pvc.yaml

Step 3: Generate Pod manifest and add PVC mount:

kubectl run storage-pod --image=nginx -n storage --dry-run=client -o yaml > /home/interview/pod.yaml

Edit pod.yaml to add volume mount:

apiVersion: v1
kind: Pod
metadata:
  name: storage-pod
  namespace: storage
spec:
  containers:
    - name: storage-pod
      image: nginx
      volumeMounts:
        - name: data
          mountPath: /data
  volumes:
    - name: data
      persistentVolumeClaim:
        claimName: expand-pvc

kubectl apply -f /home/interview/pod.yaml
kubectl wait --for=condition=Ready pod/storage-pod -n storage --timeout=60s

Step 4: Expand PVC to 2Gi:

kubectl edit pvc expand-pvc -n storage

Change spec.resources.requests.storage from 1Gi to 2Gi.

Step 5: Verify:

kubectl get storageclass fast-sc
kubectl get pvc expand-pvc -n storage
kubectl get pod storage-pod -n storage