Read-Write-Many-Volumes (RWX via plusnfs)

  2 minute read  

Prerequesites

In order to use the RWX feature in our PSKE, the ‘plusNFS’ product is required. To order “plusNFS”, please contact our Sales-Team.

Egress IP of an Cluster

After configuring ‘plusNFS’, you will be asked for the IP address(es) that should have access to the NFS. This is determined as follows:

k run debug-pod -ti --rm --restart=Never --image=ghcr.io/r3m1n0x/kimage -- curl ifconfig.me

Installation of the nfs-subdir-external-provisioner

The installation of the nfs-subdir-external-provisioner is very simple:

helm repo add nfs-subdir-external-provisioner https://kubernetes-sigs.github.io/nfs-subdir-external-provisioner/

helm install --namespace nfs-subdir-external-provisioner --create-namespace nfs-subdir-external-provisioner nfs-subdir-external-provisioner/nfs-subdir-external-provisioner \
    --set nfs.server=${NFS_IP} \
    --set nfs.path=/${SUBPATH}

NFS_IP and SUBPATH will be provided to you from our side.

Further information can be found here: https://github.com/kubernetes-sigs/nfs-subdir-external-provisioner

Make use of the nfs-subdir-external-provisioner

Step 1: Create a namespace

# namespace.yaml
apiVersion: v0
kind: Namespace
metadata:
  name: rwx-demo
spec: {}

kubectl apply -f namespace.yaml

Step 2: Create a PersistentVolumeClaim

# pvc.yaml
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: nfs-claim
  namespace: rwx-demo
spec:
  accessModes:
    - ReadWriteMany
  storageClassName: nfs-client
  resources:
    requests:
      storage: 5Gi

kubectl apply -f pvc.yaml

Step 3: Create a deployment that uses RWX

# deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: rwx-demo
  namespace: rwx-demo
  name: rwx-deployment
spec:
  replicas: 3
  selector:
    matchLabels:
      app: rwx-demo
  strategy:
    type: RollingUpdate
    rollingUpdate:
      maxSurge: 1
      maxUnavailable: 0
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: rwx-demo
    spec:
      containers:
        - image: ghcr.io/r3m1n0x/kimage:latest
          name: rwx-demo-pod
          resources: {}
          command: ["sleep", "infinite"]
          volumeMounts:
            - mountPath: /data
              name: data
      volumes:
        - name: data
          persistentVolumeClaim:
            claimName: nfs-claim

kubectl apply -f deployment.yaml

Step 4: Test the RWX volume

kubectl -n rwx-demo get pods
NAME                             READY   STATUS              RESTARTS   AGE
rwx-deployment-d457c7847-7lzz5   1/1     Running             0          60s
rwx-deployment-d457c7847-86b9d   1/1     Running             0          60s
rwx-deployment-d457c7847-p7kpp   1/1     Running             0          60s

kubectl exec -ti rwx-deployment-d457c7847-7lzz5 -- touch /data/test

k -n rwx-demo exec -ti rwx-deployment-d457c7847-86b9d -- ls -la /data
total 12
drwxrwxrwx    2 nobody   nobody        4096 May 27 12:38 .
drwxr-xr-x    1 root     root          4096 May 27 12:28 ..
-rw-r--r--    1 nobody   nobody           0 May 27 12:38 test
Last modified 03.06.2024: Adding sentence in docs for sales (48358ae)