Elastic Container Instance:Mount a NAS file system

Deploy the NAS-Controller component

Before you mount a NAS file system as a dynamically provisioned volume, you must deploy the NAS-Controller component. NAS-Controller is used to automatically create a PV of the NAS type.

1. Create a YAML file that is used to deploy NAS-Controller.

   Create a file named nas-controller.yaml and copy the following template into the file:

   apiVersion: v1
   kind: ServiceAccount
   metadata:
     name: alicloud-nas-controller
     namespace: kube-system
   ---
   kind: ClusterRole
   apiVersion: rbac.authorization.k8s.io/v1
   metadata:
     name: alicloud-nas-controller
   rules:
     - apiGroups: [""]
       resources: ["persistentvolumes"]
       verbs: ["get", "list", "watch", "create", "delete"]
     - apiGroups: [""]
       resources: ["persistentvolumeclaims"]
       verbs: ["get", "list", "watch", "update"]
     - apiGroups: ["storage.k8s.io"]
       resources: ["storageclasses"]
       verbs: ["get", "list", "watch"]
     - apiGroups: [""]
       resources: ["events"]
       verbs: ["list", "watch", "create", "update", "patch"]
     - apiGroups: [""]
       resources: ["endpoints"]
       verbs: ["get", "watch", "list", "delete", "update", "create"]
   ---
   kind: ClusterRoleBinding
   apiVersion: rbac.authorization.k8s.io/v1
   metadata:
     name: alicloud-nas-controller
   subjects:
     - kind: ServiceAccount
       name: alicloud-nas-controller
       namespace: kube-system
   roleRef:
     kind: ClusterRole
     name: alicloud-nas-controller
     apiGroup: rbac.authorization.k8s.io
   ---
   kind: Deployment
   apiVersion: apps/v1
   metadata:
     name: alicloud-nas-controller
     namespace: kube-system
   spec:
     selector:
       matchLabels:
         app: alicloud-nas-controller
     strategy:
       type: Recreate
     template:
       metadata:
         labels:
           app: alicloud-nas-controller
       spec:
         tolerations:
         - operator: Exists
         affinity:
           nodeAffinity:
             preferredDuringSchedulingIgnoredDuringExecution:
             - weight: 1
               preference:
                 matchExpressions:
                 - key: node-role.kubernetes.io/master
                   operator: Exists
             requiredDuringSchedulingIgnoredDuringExecution:
                nodeSelectorTerms:
                - matchExpressions:
                  - key: type
                    operator: NotIn
                    values:
                    - virtual-kubelet
         priorityClassName: system-node-critical
         serviceAccount: alicloud-nas-controller
         hostNetwork: true
         containers:
           - name: nfs-provisioner
             image: registry.cn-hangzhou.aliyuncs.com/acs/alicloud-nas-controller:v1.14.8.17-7b898e5-aliyun
             env:
             - name: PROVISIONER_NAME
               value: alicloud/nas
             securityContext:
               privileged: true
             volumeMounts:
             - mountPath: /var/log
               name: log
         volumes:
         - hostPath:
             path: /var/log
           name: log

2. Deploy NAS-Controller.

   kubectl create -f nas-controller.yaml

3. View the deployment result.

   kubectl -n kube-system get pods

   The following command output is expected to return:

   NAME                                        READY   STATUS           RESTARTS   AGE
   alicloud-nas-controller-6dccf695d5-zxkwg    1/1     Running          0          3m7s

Mount a NAS file system

1. Create a NAS file system and add a mount target.

   1. Log on to the NAS console.

   2. Create a NAS file system and add a mount target.

      The NAS file system and mount target must reside in the same VPC as the VNode. For more information, see Create a NAS file system and Manage mount targets.

2. Run the following command to create a StorageClass:

   1. Create a file named sc-nas.yaml and copy the following template into the file. Modify the parameters in the template as required.

      apiVersion: storage.k8s.io/v1
      kind: StorageClass
      metadata:
        name: alicloud-nas-test
      mountOptions:
      - nolock,tcp,noresvport
      - vers=3
      parameters:
        volumeAs: subpath
        server: "1e9064****-gk***.cn-beijing.nas.aliyuncs.com"
      provisioner: alicloud/nas
      reclaimPolicy: Retain

      The following table describes the parameters in the template.

      Parameter	Description
      mountOptions	The mount options, such as the NFS version.
      volumeAs	The PV type. A value of subpath indicates a subdirectory. In this case, NAS-Controller automatically creates a subdirectory of the NAS file system.
      server	The mount target of the NAS file system if you set the volumeAs parameter to subpath.
      provisioner	The type of the driver used. In this example, the parameter is set to alicloud/nas. This indicates that the FlexVolume plug-in provided by Alibaba Cloud for NAS is used.
      reclaimPolicy	The reclaim policy of the PV. Default value: Delete. You can also set this parameter to Retain. Delete: When a PVC is deleted, the related PV and NAS file system are also deleted. Retain: When a PVC is deleted, the related PV and NAS file system are retained and can only be manually deleted. If you require higher data security, we recommend that you use the Retain mode to prevent data loss caused by user errors.

   2. Run the following command to create a StorageClass:

      kubectl create -f sc-nas.yaml

3. Create a PVC of the NAS type.

   1. Create a file named pvc-nas.yaml and copy the following template into the file:

      kind: PersistentVolumeClaim
      apiVersion: v1
      metadata:
        name: pvc-nas
      spec:
        accessModes:
        - ReadWriteMany
        storageClassName: alicloud-nas-test
        resources:
          requests:
            storage: 20Gi

   2. Run the following command to create a PVC:

      kubectl create -f pvc-nas.yaml

4. Mount the NAS file system to two elastic container instance-based pods.

   1. Create a file named test-nas.yaml and copy the following template into the file:

      apiVersion: apps/v1
      kind: Deployment
      metadata:
        name: test-nas
      spec:
        replicas: 2
        selector:
          matchLabels:
            app: uid
        template:
          metadata:
            labels:
              app: uid
          spec:
            nodeSelector:
              k8s.aliyun.com/vnode: "true"
            tolerations:
            - key: k8s.aliyun.com/vnode
              operator: "Equal"
              value: "true"
              effect: "NoSchedule"
            containers:
            - name: nginx
              image: registry-vpc.cn-beijing.aliyuncs.com/eci_open/nginx:1.14.2
              volumeMounts:
              - mountPath: /data
                name: data
            volumes:
            - name: data
              persistentVolumeClaim:
                claimName: pvc-nas

   2. Run the following command to create a Deployment:

      kubectl create -f test-nas.yaml

   3. View the results.

      kubectl get pods -o wide

      The following command output is expected to return:

      NAME                               READY   STATUS    RESTARTS   AGE     IP              NODE                                  NOMINATED NODE   READINESS GATES
      
      test-nas-7cf4d9f796-4h2kj          1/1     Running   0          50s     172.16.XX.XX    cn-beijing.vnd-2ze8nd8xcl33t4pa****   <none>           <none>
      test-nas-7cf4d9f796-dv5q2          1/1     Running   0          50s     172.16.XX.XX    cn-beijing.vnd-2ze8nd8xcl33t4pa****   <none>           <none>
      

      Check the file directories in the pods and verify that the /data mount directory is generated for the NAS file system. In addition, verify that the files written to the first pod can be viewed in the second pod. This indicates that the two pods share the NAS file system.