Container Service for Kubernetes:Migrate applications across regions and clusters

Notes

• Cross-region application migration supports the backup of applications and their associated volumes that use only Alibaba Cloud disks.

  If you use an ACK dedicated cluster or a registered cluster that is connected to a self-managed Kubernetes cluster on ECS instances, verify that the required permissions for ECS disk snapshots are granted before you use the cross-region recovery feature for disk volumes. For more information, see Install the migrate-controller backup service component and configure permissions.

• When you back up an application, resources that are being deleted are not backed up.

Preparations

This topic describes how to back up and restore an application across regions and clusters. In this example, an ACK Pro cluster named Cluster_BJ in the China (Beijing) region is used as the backup cluster. An ACK Pro cluster named Cluster_SZ in the China (Shenzhen) region is used as the recovery cluster. The backup repository is associated with an Object Storage Service (OSS) bucket in the China (Beijing) region.

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

   If an OSS bucket that meets the requirements already exists in this region, you can skip this step.

2. Run the following command to create a stateful Nginx application in the default namespace of the Cluster_BJ backup cluster.

   YAML file for the stateful Nginx application

   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 application backup feature uses Alibaba Cloud OSS to store backup data. If no backup repository is available when you create a backup job, you must follow this step to create one. For more information about how to create a backup repository, see Create a backup repository.

Step 2: Back up the application in the Cluster_BJ cluster

For more information about how to back up an application, see Create a backup schedule or an immediate backup.

Step 3: Restore the application in the Cluster_SZ cluster

For more information about how to restore an application, see Step 3: Restore applications and volumes.

Step 4: Check if the Nginx application is migrated

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

2. In the navigation pane on the left of the management page for the Cluster_SZ recovery cluster, choose Workloads > StatefulSets.

3. Click Details in the Actions column for the Nginx application. Then, click the Pods tab.

   Verify that the status of the application is Running. This indicates that the Nginx application is successfully migrated.

References

• For more information about how to migrate applications between clusters that use different storage plugins or have different versions, see Use the backup center to migrate applications from Kubernetes clusters of earlier versions.

• For more information about how to use the command line to migrate cluster applications, see Use kubectl to back up and restore cluster applications.