Container Service for Kubernetes:Use dynamically provisioned disks for stateful applications

How it works

1. Create a PVC that references a StorageClass.

2. Deploy your application with a volume that references the PVC.

3. The provisioner automatically creates a disk and binds it to the PVC as a PV.

By default, a provisioner is automatically installed in each ACK cluster.

Prerequisites

• An ACK managed cluster. For more information, see Create an ACK managed cluster.

• A kubectl connection to the cluster. For more information, see Step 2: Select a type of cluster credentials.

• A provisioner installed in the cluster that can automatically create disks from a StorageClass.

Default StorageClasses

ACK creates four StorageClasses during cluster initialization. These StorageClasses use default settings and only work for single-zone clusters. For multi-zone clusters, create a custom StorageClass.

Create a custom StorageClass

If the default StorageClasses do not meet your requirements (for example, your cluster spans multiple zones), create a custom StorageClass.

1. Create a file named storageclass.yaml:

       kind: StorageClass
       apiVersion: storage.k8s.io/v1
       metadata:
         name: alicloud-disk-ssd-hangzhou-b
       provisioner: alicloud/disk
       reclaimPolicy: Retain
       parameters:
         type: cloud_ssd
         regionId: cn-hangzhou
         zoneId: cn-hangzhou-b
         fstype: "ext4"
         readonly: "false"

2. Create the StorageClass:

       kubectl create -f storageclass.yaml

Create a PVC

1. Create a file named pvc-ssd.yaml:

       kind: PersistentVolumeClaim
       apiVersion: v1
       metadata:
         name: disk-ssd
       spec:
         accessModes:
           - ReadWriteOnce
         storageClassName: alicloud-disk-ssd-hangzhou-b
         resources:
           requests:
             storage: 20Gi

2. Create the PVC:

       kubectl create -f pvc-ssd.yaml

Create a Deployment

1. Create a file named pvc-dynamic.yaml:

       apiVersion: apps/v1
       kind: Deployment
       metadata:
         name: nginx-dynamic
         labels:
           app: nginx
       spec:
         selector:
           matchLabels:
             app: nginx
         template:
           metadata:
             labels:
               app: nginx
           spec:
             containers:
             - name: nginx
               image: nginx
               volumeMounts:
                 - name: disk-pvc
                   mountPath: "/data"
             volumes:
               - name: disk-pvc
                 persistentVolumeClaim:
                   claimName: disk-ssd

2. Create the Deployment:

       kubectl create -f nginx-dynamic.yaml

Verify persistent storage

After creating the Deployment, verify that the disk is mounted and that data persists across pod restarts.