Setting up and using an NFS share in Kubernetes

In the previous post, we learned how to setup an NFS share on a Linux machine. Today, we are going to learn how to mount this share in a Kubernetes cluster.

The first thing we need to define is a PersistentVolume:

persistent-volume.yaml

 1apiVersion: v1
 2kind: PersistentVolume
 3metadata:
 4  name: my-shared-folder-pv
 5  labels:
 6    usage: my-shared-folder-pv
 7spec:
 8  capacity:
 9    storage: 50Gi
10  accessModes:
11    - ReadWriteMany
12  persistentVolumeReclaimPolicy: Recycle
13  nfs:
14    server: my-other-server
15    path: /var/nfs/my_shared_folder

Then we can create a PersistentVolumeClaim pointing to the volume:

persistent-volume-claim.yaml

 1apiVersion: v1
 2kind: PersistentVolumeClaim
 3metadata:
 4  name: my-shared-folder-pvc
 5  annotations:
 6    volume.beta.kubernetes.io/storage-class: ""
 7spec:
 8  accessModes:
 9    - ReadWriteMany
10  resources:
11    requests:
12      storage: 50Gi
13  selector:
14    matchLabels:
15      usage: my-shared-folder-pv

We can now deploy these to our Kubernetes cluster:

1kubectl apply -f persistent-volume.yaml
2kubectl apply -f persistent-volume-claim.yaml

To use it in a deployment, you can mount it now as a volume:

deployment.yaml

 1apiVersion: apps/v1
 2kind: Deployment
 3metadata:
 4  name: my-server
 5  labels:
 6    app: my-server
 7spec:
 8  replicas: 1
 9selector:
10    matchLabels:
11      app: my-server
12  template:
13    metadata:
14      labels:
15        app: my-server
16    spec:
17      containers:
18      - name: my-server
19        image: "alpine:3.12"
20        command: ["/bin/sh"]
21        args: ["-c", "while true; do date >> /mnt/my_shared_folder/dates.txt; sleep 5; done"]
22        volumeMounts:
23        - name: my-shared-folder
24          mountPath: /mnt/my_shared_folder
25      volumes:
26      - name: my-shared-folder
27        persistentVolumeClaim:
28          claimName: my-shared-folder-pvc

If you also want to setup the NFS share itself inside the cluster, there are examples available showing you how to do that in the Kubernetes Example repository.