Day 36 Task: Managing Persistent Volumes in Your Deployment 💥

What are Persistent Volumes in K8s

In Kubernetes, a Persistent Volume (PV) is a piece of storage in the cluster that has been provisioned by an administrator. A Persistent Volume Claim (PVC) is a request for storage by a user. The PVC references the PV, and the PV is bound to a specific node.

Today's tasks:

Task 1:

Add a Persistent Volume to your Deployment todo app.

• Create a file pv.yaml and write the code for Persistent Volume.

    apiVersion: v1
    kind: PersistentVolume
    metadata:
      name: pv-todo-app
    spec:
      capacity:
        storage: 1Gi
      accessModes:
        - ReadWriteOnce
      persistentVolumeReclaimPolicy: Retain
      hostPath:
        path: "/tmp/data"
  

    kubectl apply -f pv.yaml
  

  

  • Create a file pvc.yaml and write the code for Persistent Volume Claim.

      apiVersion: v1
      kind: PersistentVolumeClaim
      metadata:
        name: pvc-todo-app
      spec:
        accessModes:
          - ReadWriteOnce
        resources:
          requests:
            storage: 500Mi
    

    

    • Create a file deploymentvolumes.yaml and write the code for Deployment.

apiVersion: apps/v1
kind: Deployment
metadata:
  name: todo-app
  labels:
    app: todo
spec:
  replicas: 1
  selector:
    matchLabels:
      app: todo
  template:
    metadata:
      labels:
        app: todo
    spec:
      containers:
      - name: todo
        image: agnes1/todo
        ports:
        - containerPort: 8000
        volumeMounts:
         - name: todo-app-data
           mountPath: /app
      volumes:
        - name: todo-app-data
          persistentVolumeClaim:
            claimName: pvc-todo-app

kubectl apply -f Deployment.yml

• Verify that the Persistent Volume has been added to your Deployment by checking the Pods and Persistent Volumes status in your cluster. Use these commands.

  

Task 2:

Accessing data in the Persistent Volume,

kubectl exec -it <pod-name> -- /bin/bash

delete the pod that we used in the above step and create a new pod using the command kubectl apply -f deployment.yaml

Go inside a pod using kubectl exec command, then go to the app folder and check the todo.txt file.

Hope you find this article helpful!

Happy Learning!