Container Service for Kubernetes:Use ENS disks

Use a dynamically provisioned ENS disk volume

Step 1: Create a StorageClass

For clusters in different regions, you can use one of the following methods to create a StorageClass:

Method 1: Create a StorageClass in WaitForFirstConsumer mode

The WaitForFirstConsumer mode can resolve the issue that multiple regions are available in an ACK Edge cluster. In the following example, a StorageClass is created by using a storage-class-csi-topology.yaml file.

1. Create a file named storage-class-topology.yaml and copy the following content to the file:

   apiVersion: storage.k8s.io/v1
   kind: StorageClass
   metadata:
     name: alicloud-ens-disk-available
   provisioner: ensplugin.csi.alibabacloud.com
   parameters:
     type: available
     fsType: ext4
   volumeBindingMode: WaitForFirstConsumer
   reclaimPolicy: Retain
   allowVolumeExpansion: false

   Parameter	Description
   name	The name of the StorageClass.
   provisioner	Set the value to ensplugin.csi.alibabacloud.com. Use the ENS disk provisioner plug-in to create the StorageClass.
   type	The type of the disk.
   regionId	Optional. The region where the disk is automatically created.
   reclaimPolicy	The disk reclaim policy. Only Retain is supported. When you delete a persistent volume claim (PVC), the PV and disk data are retained and must be manually deleted.
   volumeBindingMode	The binding mode of the disk. Default value: Immediate. You can also set this parameter to WaitForFirstConsumer. Immediate: creates a disk when the PVC that uses the StorageClass is created. This way, a disk is created and a PV is provisioned before you create a pod that uses the disk. WaitForFirstConsumer: delays the binding and provisioning of a PV until a pod that uses the PVC is created. After the pod is scheduled to a node, a disk is created in the zone where the node is deployed and provisioned as the PV.

2. Run the following command to create a StorageClass:

   kubectl apply -f storage-class-topology.yaml

3. View the created 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.

   On the StorageClasses page, you can view the created StorageClass.

Method 2: Create a StorageClass by creating a disk and then creating a pod

1. Create a file named storage-class-csi.yaml and copy the following content to the file:

   apiVersion: storage.k8s.io/v1
   kind: StorageClass
   metadata:
     name: alicloud-ens-disk-available
   provisioner: ensplugin.csi.alibabacloud.com
   parameters:
     type: available
     regionId: xxx
   reclaimPolicy: Retain
   allowVolumeExpansion: false
   volumeBindingMode: Immediate

2. Run the following command to create a StorageClass:

   kubectl apply -f storage-class-csi.yaml

3. View the created 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.

   On the StorageClasses page, you can view the created StorageClass.

Step 2: Create a PVC

1. Create a file named pvc-ssd.yaml and copy the following content to the file:

   apiVersion: v1
   kind: PersistentVolumeClaim
   metadata:
     name: disk-pvc
   spec:
     accessModes:
     - ReadWriteOnce
     volumeMode: Filesystem
     resources:
       requests:
         storage: 25Gi
     storageClassName: alicloud-ens-disk-available

2. Run the following command to create a PVC:

   kubectl create -f pvc-ssd.yaml

3. View the created PVC.

   In the left-side navigation pane of the details page, choose Volumes > Persistent Volume Claims. On the Persistent Volume Claims page, you can view the created PVC.

Step 3: Create an application

1. Create a file named pvc-dynamic.yaml and copy the following content to the file:

   Use the following template to create an application named nginx-dynamic and mount the PVC to the application.

   apiVersion: apps/v1
   kind: StatefulSet
   metadata:
     name: nginx-dynamic
   spec:
     selector:
       matchLabels:
         app: nginx
     template:
       metadata:
         labels:
           app: nginx
       spec:
         containers:
         - name: nginx
           image: nginx
           ports:
           - containerPort: 80
             name: web
           volumeMounts:
           - name: pvc-disk
             mountPath: /data
         volumes:
           - name: pvc-disk
             persistentVolumeClaim:
               claimName: disk-pvc

   Parameter	Description
   mountPath	The path to which the disk is mounted.
   claimName	The name of the PVC that is mounted to the application.

2. Run the following command to create the application and mount the PVC to the application:

   kubectl create -f pvc-dynamic.yaml

3. View the created application.

   In the left-side navigation pane of the details page, choose Workloads > StatefulSets. On the StatefulSets page, you can find the created application.

Use a statically provisioned ENS disk volume

Step 1: Create a PV

1. Create a file named pv-static.yaml and copy the following content to the file:

   apiVersion: v1
   kind: PersistentVolume
   metadata:
     name: csi-pv
     labels:
       alicloud-pvname: static-disk-pv
   spec:
     capacity:
       storage: 25Gi
     accessModes:
       - ReadWriteOnce
     persistentVolumeReclaimPolicy: Retain
     csi:
       driver: ensplugin.csi.alibabacloud.com
       volumeHandle: "<your-disk-id>"
     nodeAffinity:
       required:
         nodeSelectorTerms:
         - matchExpressions:
           - key: topology.ensplugin.csi.alibabacloud.com/region
             operator: In
             values:
             - "<your-node-region-id>"     # The region ID of the ENS node. To view the region ID of an ENS node, view the topology.ensplugin.csi.alibabacloud.com/region parameter in the label of the ENS node.

   Parameter	Description
   name	The name of the PV.
   labels	The labels that you want to add to the PV.
   storage	The available storage of the cloud disk.
   accessModes	The access mode of the PV.
   persistentVolumeReclaimPolicy	The reclaim policy of the PV.
   driver	The type of driver. The value ensplugin.csi.alibabacloud.com specifies that the ENS disk in the CSI plug-in is used.
   volumeHandle	The ID of the cloud disk that is associated with the PV.
   nodeAffinity	The information about the zone to which the PV and PVC belong. You can configure this parameter to specify the zone to which the pod that uses the PV and PVC is scheduled.

2. Run the following command to create the PV:

   kubectl create -f pv-static.yaml

3. View the PV that you created.

   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 > Persistent Volumes.

   On the Persistent Volumes page, you can view the created PV.

Step 2: Create a PVC

1. Create a file named pvc-static.yaml and copy the following content to the file:

   apiVersion: v1
   kind: PersistentVolumeClaim
   metadata:
     name: csi-pvc
   spec:
     accessModes:
     - ReadWriteOnce
     resources:
       requests:
         storage: 25Gi
     selector:
       matchLabels:
         alicloud-pvname: static-disk-pv

   Parameter	Description
   name	The name of the PVC.
   accessModes	The access mode of the PVC.
   storage	The capacity claimed by the PVC. The claimed capacity cannot exceed the capacity of the PV that is bound to the PVC.
   matchLabels	The labels that are used to select and bind a PV to the PVC. The labels must be the same as those of the PV to be bound to the PVC.

2. Run the following command to create a PVC:

   kubectl create -f pvc-static.yaml

3. View the created PVC.

   In the left-side navigation pane of the details page, choose Volumes > Persistent Volume Claims. On the Persistent Volume Claims page, you can view the created PVC.

Step 3: Create an application

In this example, a web application is created and mounted with the PVC you created.

1. Create a file named web.yaml and copy the following content to the file:

   apiVersion: apps/v1
   kind: StatefulSet
   metadata:
     name: web
   spec:
     selector:
       matchLabels:
         app: nginx
     serviceName: "nginx"
     template:
       metadata:
         labels:
           app: nginx
       spec:
         containers:
         - name: nginx
           image: nginx
           ports:
           - containerPort: 80
             name: web
           volumeMounts:
           - name: pvc-disk
             mountPath: /data
         volumes:
           - name: pvc-disk
             persistentVolumeClaim:
               claimName: csi-pvc

   Parameter	Description
   mountPath	The path to which the disk is mounted.
   claimName	The name of the PVC that is mounted to the application.

2. Run the following command to create an application that is mounted with a statically provisioned ENS disk volume by using the PVC:

   kubectl apply -f web.yaml

3. In the left-side navigation pane of the details page, choose Workloads > StatefulSets.

   On the StatefulSets page, you can view the web application and the application can be started as expected. This indicates that the ENS disk is mounted.