CKA Prep Series part 2: Dynamic Provisioning

Part 2: Dynamic Provisioning with a PVC and a Pod

Continuing the CKA prep series with dynamic provisioning. In this blog post, I’ll be creating a PVC and a Pod.

This is a follow-up post from my first blog post in the series:
CKA Prep Series part 1: Creating StorageClasses

Q2. In Namespace storage:

• Create a PVC named data-pvc requesting 1Gi with access mode ReadWriteOnce using the retain-storage StorageClass.
• Create a Pod named writer that mounts the PVC at /data.
• Exec into the Pod and create file /data/test.txt on the volume.

Step 1: Create the PVC data-pvc

I like to use:

vi pvc.yaml

and edit the file with insert from the keyboard.

The template should look like this (notice the values from the task):

textapiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: data-pvc
  namespace: storage # <-- important: the task says “In Namespace storage”
spec:
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 1Gi
  storageClassName: retain-storage

Apply it:

kubectl apply -f pvc.yaml

Check that the PVC is pending:

kubectl get pvc -n storage

With volumeBindingMode: WaitForFirstConsumer

This is what you used in your retain-storage StorageClass:

• The PVC will stay Pending even if dynamic provisioning is available.
• The PV is only created when a Pod that uses the PVC is scheduled.
• Binding happens at Pod scheduling time, not at PVC creation time.

When you see data-pvc with status Bound: This means dynamic provisioning created a PV automatically using the retain-storage StorageClass.

Step 3: Create the Pod writer

Again, I use:

vi pod.yaml

The template should look like this:

Apply it:

kubectl apply -f pod.yaml

Wait for the Pod to be running:

kubectl get pod writer -n storage

Step 4: Exec into the Pod and create a file

Now, exec into the Pod:

kubectl exec -it writer -n storage --sh

Inside the Pod, create the file:

Option 1 – Using echo

echo "CKA prep test" > /data/test.txt

Option 2 – Using cd and touch

cd /data
touch test.txt

Both work; echo also writes content into the file, while touch just creates an empty file.

Verify it exists:

ls -l /data/test.txt
cat /data/test.txt

Exit the Pod:

type exit