Container Service for Kubernetes:Mount a dynamically provisioned NAS volume

Step 1: Create a StorageClass

1. Save the following YAML content as nas-sc.yaml.

   apiVersion: storage.k8s.io/v1
   kind: StorageClass
   metadata:
     name: alicloud-nas
   mountOptions:
   - nolock,tcp,noresvport
   - vers=3
   parameters:
     server: "23a9649583-i****.cn-shenzhen.nas.aliyuncs.com:/nasroot1/"
     driver: flexvolume
   provisioner: alicloud/nas
   reclaimPolicy: Delete

2. Create the StorageClass:

   kubectl apply -f nas-sc.yaml

3. Verify the StorageClass:

   kubectl get sc alicloud-nas

   Expected output:

   NAME            PROVISIONER    RECLAIMPOLICY   VOLUMEBINDINGMODE   ALLOWVOLUMEEXPANSION   AGE
   alicloud-nas    alicloud/nas   Delete          Immediate           false                  10s

Step 2: Deploy a StatefulSet with NAS volumes

1. Save the following YAML content as nas-statefulset.yaml. This creates a headless Service and a StatefulSet that uses dynamically provisioned NAS volumes.

   apiVersion: v1
   kind: Service
   metadata:
     name: nginx
     labels:
       app: nginx
   spec:
     ports:
     - port: 80
       name: web
     clusterIP: None
     selector:
       app: nginx
   ---
   apiVersion: apps/v1
   kind: StatefulSet
   metadata:
     name: web
   spec:
     selector:
       matchLabels:
         app: nginx
     serviceName: "nginx"
     replicas: 5
     volumeClaimTemplates:
     - metadata:
         name: html
       spec:
         accessModes:
           - ReadWriteOnce
         storageClassName: alicloud-nas
         resources:
           requests:
             storage: 2Gi
     template:
       metadata:
         labels:
           app: nginx
       spec:
         containers:
         - name: nginx
           image: nginx:alpine
           volumeMounts:
           - mountPath: "/data"
             name: html

2. Deploy the Service and StatefulSet:

   kubectl apply -f nas-statefulset.yaml

3. Verify that the PVCs are bound:

   kubectl get pvc

   Expected output:

   NAME         STATUS   VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS   AGE
   html-web-0   Bound    pvc-xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx   2Gi        RWO            alicloud-nas   2m
   html-web-1   Bound    pvc-xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx   2Gi        RWO            alicloud-nas   2m
   html-web-2   Bound    pvc-xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx   2Gi        RWO            alicloud-nas   1m
   html-web-3   Bound    pvc-xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx   2Gi        RWO            alicloud-nas   1m
   html-web-4   Bound    pvc-xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx   2Gi        RWO            alicloud-nas   1m

4. Verify that all pods are running:

   kubectl get pods -l app=nginx

   Expected output:

   NAME    READY   STATUS    RESTARTS   AGE
   web-0   1/1     Running   0          3m
   web-1   1/1     Running   0          2m
   web-2   1/1     Running   0          2m
   web-3   1/1     Running   0          1m
   web-4   1/1     Running   0          1m

Verify data persistence

After the StatefulSet is running, confirm that data persists across pod restarts.

1. Write a test file to a pod:

   kubectl exec web-0 -- sh -c "echo 'Hello from NAS' > /data/test.txt"

2. Read the file:

   kubectl exec web-0 -- cat /data/test.txt

   Expected output:

   Hello from NAS

3. Delete the pod and wait for Kubernetes to recreate it:

   kubectl delete pod web-0
   kubectl wait --for=condition=Ready pod/web-0 --timeout=120s

4. Read the file again after pod recreation:

   kubectl exec web-0 -- cat /data/test.txt

   If the output still shows Hello from NAS, the NAS volume persists data correctly.

Clean up resources

Delete the resources in the following order:

1. Delete the StatefulSet:

   kubectl delete statefulset web

2. Delete the Service:

   kubectl delete service nginx

3. Delete the PVCs:

   kubectl delete pvc -l app=nginx

4. Delete the StorageClass:

   kubectl delete sc alicloud-nas