Create PersistentVolume, PersistentVolume on Kubernetes

Introduction

I will show how to create PersistentVolume and PersistentVolumeClaim on Kubernetes. I am using Minikube for our learning.

We will first create an  index.html file for our Nginx pod and then use this file in our PersistentVolume and PersistentVolumeClaim for storage in our Pod.

Storage

You can login to Minikube using:

$ minikube ssh
Last login: Sun Oct 10 01:14:15 2021 from 192.168.49.1
docker@minikube:~$

We will now create index.html file at /mnt/data/index.html :

$ sudo mkdir /mnt/data
$ sudo sh -c "echo 'Hello from PVC example' > /mnt/data/index.html"

PersistentVolume

We can create a PersistentVolume using yaml:

apiVersion: v1
kind: PersistentVolume
metadata:
  name: ashok-pv-vol
  labels:
    type: local
spec:
  storageClassName: manual
  capacity:
    storage: 20Gi
  accessModes:
    - ReadWriteOnce
  hostPath:
    path: "/mnt/data"

Apply the PV:

$ kubectl apply -f pv.yaml
persistentvolume/ashok-pv-vol created

We can check the status of the PersistentVolume:

$ kubectl get pv
NAME           CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS      CLAIM   STORAGECLASS   REASON   AGE
ashok-pv-vol   20Gi       RWO            Retain           Available           manual                  4s

PersistentVolumeClaim

We will create an PersistentVolumeClaim using yaml:

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: ashok-pv-claim
spec:
  storageClassName: manual
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 20Gi

PersistentVolumeClaim can be created as below:

$ kubectl apply -f pvc.yaml
persistentvolumeclaim/ashok-pv-claim created

We can check the status of the PersistentVolumeClaim:

$ kubectl get pvc
NAME             STATUS   VOLUME         CAPACITY   ACCESS MODES   STORAGECLASS   AGE
ashok-pv-claim   Bound    ashok-pv-vol   20Gi       RWO            manual         8s

The persistent volume status is now changed to bound :

$ kubectl get pv
NAME           CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS   CLAIM                    STORAGECLASS   REASON   AGE
ashok-pv-vol   20Gi       RWO            Retain           Bound    default/ashok-pv-claim   manual                  2m31s

Let's create a pod for using the static volume.

Using PVC in Pod

We will create a pod using yaml:

apiVersion: v1
kind: Pod
metadata:
  name: ashok-pv-pod
spec:
  volumes:
    - name: ashok-pv-storage
      persistentVolumeClaim:
        claimName: ashok-pv-claim
  containers:
    - name: ashok-pv-container
      image: nginx
      ports:
        - containerPort: 80
          name: "http-server"
      volumeMounts:
        - mountPath: "/usr/share/nginx/html"
          name: ashok-pv-storage

Let's create pod:

$ kubectl apply -f pv-pod.yaml
pod/ashok-pv-pod created

We will check the status of the pod:

$ kubectl get po
NAME           READY   STATUS    RESTARTS   AGE
ashok-pv-pod   1/1     Running   0          79s

To make this pod accessible from browser, you can use  kubectl port-forward :

$ kubectl port-forward nginx 8888:80
Forwarding from 127.0.0.1:8888 -> 80
Forwarding from [::1]:8888 -> 80

Open the browser  http://localhost:8888/ :

Clean Up

We can delete the pod, pvc and pv using below commands:

$ kubectl delete po ashok-pv-pod
pod "ashok-pv-pod" deleted
$ kubectl delete pvc ashok-pv-claim
persistentvolumeclaim "ashok-pv-claim" deleted
$ kubectl delete pv ashok-pv-vol
persistentvolume "ashok-pv-vol" deleted

Let me know if you need any help.

Happy Coding !!!