Container Service for Kubernetes:Mount a dynamically provisioned NAS volume and test whether the NAS volume can persist and share data

Mount a dynamically provisioned NAS volume in subpath mode in the ACK console

Step 1: Create a NAS file system and a mount target

To mount a dynamically provisioned NAS volume in subpath mode, you must create a NAS file system and a mount target.

1. Log on to the NAS console

2. Create a NAS file system. For more information, see Create a file system.

   Note

   If you want to encrypt data in a NAS volume, configure the encryption settings when you create the NAS file system.

3. Create a mount target in the virtual private cloud (VPC) in which the cluster nodes are deployed. For more information, see Manage mount targets.

Step 2: Create a StorageClass

1. Log on to the ACK console. In the left-side navigation pane, click Clusters.

2. On the Clusters page, find the cluster that you want to manage and click its name. In the left-side pane, choose Volumes > StorageClasses.

3. In the upper-right corner of the StorageClasses page, click Create.

4. In the Create dialog box, configure the StorageClass.

   The following table describes the key parameters.

   Parameter	Description
   Name	The name of the StorageClass. The name must start with a lowercase letter, and can contain only lowercase letters, digits, periods (.), and hyphens (-).
   PV Type	Valid values: Cloud Disk and NAS. In this example, NAS is selected.
   Select Mount Target	The mount target of the NAS file system. For more information about how to query the domain name of a mount target, see the View the domain name of a mount target section of the "Manage mount targets" topic. If no mount target is available, create a NAS file system first. For more information, see Use CNFS to manage NAS file systems (recommended).
   Reclaim Policy	Reclaim Policy Valid values: Delete and Retain. Default value: Delete. Delete: If you use this policy, you must also specify the archiveOnDelete parameter. If you set the archiveOnDelete parameter to true, the PV and NAS file system associated with a PVC are renamed and retained after you delete the PVC. If you set the archiveOnDelete parameter to false, the PV and NAS file system associated with a PVC are deleted after you delete the PVC. Retain mode: If a PVC is deleted, the associated 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 policy to prevent data loss caused by user errors.
   Mount Options	The mount options, such as the Network File System (NFS) version. We recommend that you use NFS v3. Extreme NAS file systems support only NFS v3 For more information about the NFS protocol, see NFS.
   Mount Path	The mount path of the NAS file system.

5. After you configure the parameters, click Create.

   After the StorageClass is created, you can view the StorageClass on the StorageClasses page.

Step 3: Create a PVC

1. In the left-side navigation pane of the details page, choose Volumes > Persistent Volume Claims.

2. In the upper-right corner of the Persistent Volume Claims page, click Create.

3. In the Create PVC dialog box, configure the parameters.

   Parameter	Description
   PVC Type	Valid values: Cloud Disk, NAS, and OSS. In this example, NAS is selected.
   Name	The name of the PVC. The name must be unique within the cluster.
   Allocation Mode	The allocation mode of the PVC. In this example, Use StorageClass is selected.
   Existing Storage Class	The StorageClass that is used to enable dynamic provisioning. Click Select. In the Select Storage Class dialog box, find the StorageClass that you want to use and click Select in the Actions column.
   Capacity	The capacity claimed by the PVC.
   Access mode	The access mode of the PVC. Default value: ReadWriteMany. You can also select ReadWriteOnce or ReadOnlyMany.

4. Click Create.

Step 4: Create an application

1. In the left-side navigation pane of the details page, choose Workloads > Deployments.

2. On the Deployments page, click Create from Image.

3. Configure the application parameters.

This example shows how to configure the volume parameters. For more information about other parameters, see Create a stateless application by using a Deployment.

You can add local volumes and cloud volumes.

• Add Local Storage: You can select HostPath, ConfigMap, Secret, or EmptyDir from the PV Type drop-down list. Then, set the Mount Source and Container Path parameters to mount the volume to a container path. For more information, see Volumes.

• Add PVC: You can add cloud volumes.

In this example, a NAS volume is mounted to the /tmp path in the container.

4. After the application configuration is completed, click Create.

Mount a dynamically provisioned NAS volume in subpath mode by using kubectl

Mount a dynamically provisioned NAS volume in filesystem mode by using kubectl

If you mount a NAS volume to a pod in filesystem mode, you can create only one NAS file system and one mount target.

You must perform all the following steps for ACK dedicated clusters. For other types of clusters, start from Step 2.

1. Optional: Configure a Resource Access Management (RAM) policy and attach the policy to the RAM role assigned to your cluster.

   If you use an ACK dedicated cluster, you must perform this step.

   The filesystem mode allows you to dynamically create and delete NAS file systems and mount targets. To perform these operations in an ACK dedicated cluster, you must grant the required permissions to CSI-Provisioner. The following sample code shows a RAM policy that contains the required permissions:

   {
       "Action": [
           "nas:DescribeMountTargets",
           "nas:CreateMountTarget",
           "nas:DeleteFileSystem",
           "nas:DeleteMountTarget",
           "nas:CreateFileSystem"
       ],
       "Resource": [
           "*"
       ],
           "Effect": "Allow"
   }

   You can grant the permissions by using one of the following methods:

   • Attach the preceding RAM policy to the master RAM role of your ACK dedicated cluster. For more information, see Modify the document and description of a custom policy.

   • Create a RAM user and attach the preceding RAM policy to the RAM user. Generate an AccessKey pair and then specify the AccessKey pair in the env variable in the CSI-Provisioner configurations.

     env:
     - name: CSI_ENDPOINT
       value: unix://socketDir/csi.sock
     - name: ACCESS_KEY_ID
       value: ""
     - name: ACCESS_KEY_SECRET
       value: ""

2. Create a StorageClass.

   1. Create a file named alicloud-nas-fs.yaml and add the following content to the file:

      apiVersion: storage.k8s.io/v1
      kind: StorageClass
      metadata:
        name: alicloud-nas-fs
      mountOptions:
      - nolock,tcp,noresvport
      - vers=3
      parameters:
        volumeAs: filesystem
        fileSystemType: standard
        storageType: Performance
        regionId: cn-beijing
        zoneId: cn-beijing-e
        vpcId: "vpc-2ze2fxn6popm8c2mzm****"
        vSwitchId: "vsw-2zwdg25a2b4y5juy****"
        accessGroupName: DEFAULT_VPC_GROUP_NAME
        deleteVolume: "false"
      provisioner: nasplugin.csi.alibabacloud.com
      reclaimPolicy: Retain

      Parameter	Description
      volumeAs	The mount mode of the NAS file system. Valid values: filesystem: The provisioner automatically creates a NAS file system. Each PV corresponds to a NAS file system. subpath: The provisioner automatically creates a subdirectory in a NAS file system. Each PV corresponds to a subdirectory of the NAS file system.
      fileSystemType	The type of the NAS file system. Valid values: standard: General-purpose NAS file system extreme: Extreme NAS file system Default value: standard.
      storageType	The storage type of the NAS file system. If the fileSystemType parameter is set to standard, the valid values are Performance and Capacity. Default value: Performance. If the fileSystemType parameter is set to extreme, the valid values are standard and advance. Default value: standard.
      regionId	The ID of the region to which the NAS file system belongs.
      zoneId	The ID of the zone to which the NAS file system belongs.
      vpcId	The ID of the VPC to which the mount target of the NAS file system belongs.
      vSwitchId	The ID of the vSwitch to which the mount target of the NAS file system belongs.
      accessGroupName	The permission group to which the mount target of the NAS file system belongs. Default value: DEFAULT_VPC_GROUP_NAME.
      deleteVolume	The reclaim policy of the NAS file system when the related PV is deleted. NAS is a shared storage service. Therefore, you must specify both deleteVolume and reclaimPolicy parameters to ensure data security.
      provisioner	The type of the driver. In this example, the parameter is set to nasplugin.csi.alibabacloud.com. This indicates that the CSI plug-in provided by Alibaba Cloud is used.
      reclaimPolicy	The reclaim policy of the PV When you delete a PVC, the related NAS file system is automatically deleted only if you set the deleteVolume parameter to true and the reclaimPolicy parameter to Delete.

   2. Run the following command to create a StorageClass:

      kubectl create -f alicloud-nas-fs.yaml

3. Create a PVC and pods to mount a NAS volume.

   1. Create a file named pvc.yaml and add the following content to the file:

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

   2. Create a file named nginx.yaml and add the following content to the file:

      apiVersion: apps/v1
      kind: Deployment
      metadata:
        name: deployment-nas-fs
        labels:
          app: nginx
      spec:
        selector:
          matchLabels:
            app: nginx
        template:
          metadata:
            labels:
              app: nginx
          spec:
            containers:
            - name: nginx
              image: nginx:1.7.9
              ports:
              - containerPort: 80
              volumeMounts:
                - name: nas-pvc
                  mountPath: "/data"
            volumes:
              - name: nas-pvc
                persistentVolumeClaim:
                  claimName: nas-csi-pvc-fs

   3. Run the following command to create the PVC and pods:

      kubectl create -f pvc.yaml -f nginx.yaml

In filesystem mode, the CSI driver automatically creates a NAS file system and a mount target when you create the PVC. When the PVC is deleted, the file system and the mount target are retained or deleted based on the settings of the deleteVolume and reclaimPolicy parameters.