Container Service for Kubernetes:Migrate applications across regions and clusters

Before you begin

Review these constraints before proceeding.

Prerequisites

Make sure you have:

• A destination cluster running Kubernetes 1.18 or later (Create an ACK managed cluster, Create an ACK dedicated cluster (no longer available for new creation), or Create a registered cluster and connect to a data center cluster).

• A destination cluster that uses the CSI storage plugin.

• System components installed in the destination cluster before restoring:

  • ACR passwordless add-on: Grant permissions and configure acr-configuration.

  • ALB Ingress add-on: Configure ALBConfig and other settings.

• The migrate-controller add-on installed and permissions configured on both clusters. See Install the migrate-controller backup service component and configure permissions.

• ECS cloud disk snapshots enabled. See Enable ECS cloud disk snapshots. The snapshot service is free to enable. Snapshots incur pay-as-you-go charges based on size and retention. See Snapshot billing.

Preparations

This example uses the following setup:

• Backup cluster: ACK Pro cluster Cluster_BJ in the China (Beijing) region

• Recovery cluster: ACK Pro cluster Cluster_SZ in the China (Shenzhen) region

• Backup repository: Associated with an OSS bucket in the China (Beijing) region

Step 1: In the China (Beijing) region, create an OSS bucket with a name that starts with cnfs-oss-***.

If a qualifying OSS bucket already exists in this region, skip this step.

Step 2: Create a stateful Nginx application in the default namespace of Cluster_BJ.

cat << EOF | kubectl apply -f -
apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: web
spec:
  selector:
    matchLabels:
      app: nginx
  serviceName: "nginx"
  replicas: 1
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
        - name: nginx
          image: nginx:1.14.2
          ports:
            - containerPort: 80
              name: web
          volumeMounts:
            - name: www
              mountPath: /usr/share/nginx/html
  volumeClaimTemplates:
    - metadata:
        name: www
        labels:
          app: nginx
      spec:
        accessModes: [ "ReadWriteOnce" ]
        storageClassName: "alicloud-disk-topology-alltype"
        resources:
          requests:
            storage: 20Gi
EOF

Step 1: Create a backup repository

The backup center stores backup data in OSS. Create a repository if none exists.

See Create a backup repository.

Step 2: Back up the application in Cluster_BJ

See Create a backup schedule or an immediate backup.

Step 3: Restore the application in Cluster_SZ

See Restore applications and volumes.

Step 4: Verify the migration

Confirm the Nginx application is running correctly in Cluster_SZ.

Using kubectl:

kubectl get pods -n default
kubectl get pvc -n default

Confirm the Pod status is Running and the PersistentVolumeClaim (PVC) is Bound.

Using the console:

1. Log on to the Container Service Management Console. In the left-side navigation pane, click Clusters.

2. On the Cluster_SZ management page, in the left-side navigation pane, choose Workloads > StatefulSets.

3. In the Actions column for the Nginx application, click Details, then click the Pods tab. Confirm the application status is Running.

Next steps

• To migrate between clusters with different storage plugins or Kubernetes versions, see Use the backup center to migrate applications from Kubernetes clusters of earlier versions.

• To migrate applications with the command line, see Use kubectl to back up and restore cluster applications.