Container Service for Kubernetes:Use kubectl to back up and restore applications

Scenarios

• You cannot manage the backup center in the Container Service for Kubernetes (ACK) console because you do not have the required permissions.

• You want to automate the backup procedure.

Notes

• You cannot delete backup and restore tasks by running the kubectl delete command. For more information, see Step 4: Delete resources related to the backup center.

• Pay close attention to the new releases of the backup center component named migrate-controller and update the component to the latest version at your earliest convenience. For more information, see Manage components.

• Do not delete the parameters in the following sample code to ensure the backup files can be restored.

Step 1: Create a backup vault

1. Use the following content to create a backuplocation.yaml file in the backup and restore clusters.

   apiVersion: csdr.alibabacloud.com/v1beta1
   kind: BackupLocation
   metadata:
     name: <yourBackuplocationName>
     namespace: csdr
   spec:
     backupSyncPeriod: 0s
     config:
       network: internal
       region: cn-beijing
     objectStorage:
       bucket: <cnfs-oss-yourBucketName>
       prefix: <subDir>
     provider: alibabacloud

   The following table describes the parameters that you need to specify. Keep the default setting for other parameters.

   Parameter	Required	Description
   name	Yes	The name of the backup vault. The name must comply with the Kubernetes naming convention.
   network	Yes	The network mode that is used to access the specified Object Storage Service (OSS) bucket. Valid values: internal: internal network. All associated clusters and the OSS bucket must be deployed in the same region. public: Internet. No region limit is imposed.
   region	Yes	The region where the OSS bucket that you want to use is deployed.
   bucket	Yes	The name of the OSS bucket. Make sure that the OSS bucket name exists and starts with cnfs-oss-.
   prefix	No	The subdirectory in the OSS bucket. If you specify this parameter, backups are stored in the specified subdirectory.

2. Run the following command in the backup and restore clusters to deploy the backuplocation object.

   kubectl apply -f backuplocation.yaml

3. Run the following command in the backup and restore clusters to check the status of the backuplocation object.

   kubectl describe backuplocation <yourBackuplocationName> -n csdr

   Expected result:

   ...
   Status:
     Last Validation Time:  2022-12-08T04:00:22Z
     Message:               success by csdr-controller
     Phase:                 Available

   The output indicates that the status of the created backup vault is Available. This indicates that the current cluster has the permissions to access the OSS bucket.

Step 2: Create a backup task

Step 3: Create a restore task

1. Use the following content to create an applicationrestore.yaml file in the restore cluster.

   apiVersion: csdr.alibabacloud.com/v1beta1
   kind: ApplicationRestore
   metadata:
     annotations:    
       csdr.alibabacloud.com/backuplocations: >-
         {"name":"<yourBackuplocationName>","region":"cn-beijing","bucket":"<cnfs-oss-yourBucketName>","prefix":"<subDir>","provider":"alibabacloud"}
     name: <yourApplicationRestoreName>
     namespace: csdr
   spec:
     appRestoreOnly: false
     preserveNodePorts: true
     includedNamespaces:
       - default
     includedResources:
       - statefulset
     excludedResources:
       - secret
     convertedarg:
     - convertToStorageClassType: alicloud-disk-topology-alltype
       convertToAccessModes:
       - ReadWriteOnce
       namespace: nas
       persistentVolumeClaim: pvc-nas
     - convertToStorageClassType: alicloud-disk-topology-alltype
       namespace: oss
       persistentVolumeClaim: pvc-oss
     backupName: <yourApplicationBackupName>
     namespaceMapping:
       <backupNamespace>: <restoreNamespace>
     imageRegistryMapping:
       <oldImageRegistry>: <newImageRegistry>

   The following table describes the parameters that you need to specify. Keep the default setting for other parameters.

   Note

   The appRestoreOnly, preserveNodePorts, includedResources, and excludedResources parameters are supported only for application backup. These parameters do not take effect in data protection scenarios.

   Parameter	Required	Description
   csdr.alibabacloud.com/backuplocations	Yes	The backup vault that stores the backups. Make sure that the information is the same as the configuration of the backup vault.
   name	Yes	The name of the restore job.
   appRestoreOnly	No	This parameter takes effect only for application backup tasks, not for data protection tasks. Specifies whether to restore only applications from backups that contain volume data. Persistent volume claims (PVCs), persistent volumes (PVs), and the relevant data are not restored. Valid values: true: restores only applications. If you want to change the data source where you back up applications, you need to manually create a PVC and PV, create a restore task, and then set this parameter to true. false: restores applications and the relevant volume data. Default value: false.
   preserveNodePorts	No	This parameter takes effect only for application backup tasks, not for data protection tasks. Specifies whether to retain the NodePort of the application. If the backup cluster and restore cluster use the same NodePort, set this parameter to false to change the NodePort to a random port. In other scenarios, set the parameter to true.
   includedNamespaces	Yes	The name of the namespace to be restored. If you leave this parameter empty, all namespaces that have been backed up are restored.
   includedResources	No	This parameter takes effect only for application backup tasks, not for data protection tasks. The type of cluster resource to be included in the restore list. Important To avoid unexpected backup results, you need to configure only one of the includedResources and excludedResources parameters. If you leave both parameters empty, all resourcetypes are restored.
   excludedResources	No	This parameter takes effect only for application backup tasks, not for data protection tasks. The type of cluster resource to be excluded from the restore list. Important To avoid unexpected backup results, you need to configure only one of the includedResources and excludedResources parameters. If you leave both parameters empty, all resourcetypes are restored.
   backupName	Yes	The name of the backup to be restored. If you use the scheduled backup feature, you need to specify the name of a backup that is created at a specific point in time, such as <yourBackupScheduleName>-20221205225845.
   namespaceMapping	No	This parameter maps the namespace in the backup cluster to a namespace in the restore cluster. Valid values: <backupNamespace>: the namespace in the backup cluster that is specified when you create the backup task. <restoreNamespace>: the namespace in the restore cluster to which the resources are restored. If you do not specify this parameter, the resources are restored to a namespace that uses the same name as the namespace in the backup cluster. Note If <restoreNamespace> does not exist, the system automatically creates one.
   imageRegistryMapping	No	Redefines the image repository address. This parameter applies to all image configurations of applications that match the rule. Valid values: <oldImageRegistry>: the original image repository address of the application in the backup. <newImageRegistry>: the destination image repository address for restoration. If you do not set this parameter, the image configuration of the application remains unchanged. Example: The image used by the application in the original cluster is registry.cn-beijing.aliyuncs.com/my-registry/nginx:v1, and you want to change it to registry.cn-hangzhou.aliyuncs.com/my-registry/nginx:v1. Configure this field as follows: namespaceMapping: "registry.cn-beijing.aliyuncs.com/my-registry/": "registry.cn-beijing.aliyuncs.com/my-registry/"
   convertedarg	No	The list of StorageClass conversions. For volumes of the FileSystem type, such as OSS, NAS, CPFS, and local volumes, you can configure this parameter to convert the StorageClasses of their PVCs to the specified StorageClass during the restoration process. For example, you can convert NAS volumes to disk volumes. convertToStorageClassType: the desired StorageClass. Make sure that the StorageClass exists in the current cluster. You can specify only the disk or NAS StorageClass. namespace: the namespace of the PVC. persistentVolumeClaim: the name of the PVC. These are the required parameters for the StorageClass conversion feature. When you convert the StorageClass, you can also use the following optional parameter to modify the AccessModes configuration of the volume. convertToAccessModes: the list of target AccessModes. Note When you restore volumes whose AccessModes are ReadWriteMany or ReadOnlyMany to disk StorageClasses, you must also convert the AccessModes to ReadWriteOnce to avoid the risk of forced disk detachment. You can run the kubectl -ncsdr describe <backup-name> command to query the PVC information in the backup. In the output, the status.resourceList.dataResource.pvcBackupInfo list contains the dataType field, which can be FileSystem or Snapshot. The nameSpace and pvcName fields specify the namespace and name of the PVC.

2. Run the following command in the restore cluster to deploy the applicationrestore object.

   kubectl apply -f applicationrestore.yaml

3. Run the following command in the restore cluster to query the status of the restore task:

   kubectl describe applicationrestore <yourApplicationRestoreName> -n csdr

   Expected result:

   ...
   Status:
     Completion Timestamp:  2022-12-05T15:52:19Z
     Phase:                 Completed
     Start Timestamp:       2022-12-05T15:52:09Z

   When the status of the restore task changes from Inprogress to Completed, the restore task is created.

Step 4: Delete resources related to the backup center

Delete a backup schedule

Run the following command to delete the BackupSchedule resource of the backup schedule to stop the backup schedule.

kubectl delete backupschedule <yourBackupSchedule> - ncsdr

Delete a backup task or restore task

1. Use the following content to create a deleterequest.yaml file in the cluster where you want to delete the task.

   apiVersion: csdr.alibabacloud.com/v1beta1
   kind: DeleteRequest
   metadata:
     name: <objectName-dbr>
     namespace: csdr
   spec:
     deleteObjectName: <objectName>
     deleteObjectType: "Backup"

   The following table describes the parameters that you need to specify. Keep the default setting for other parameters.

   Parameter	Required	Description
   name	Yes	The name of the request. To delete a backup task, specify the request name in the following format: ApplicationBackup name of the backup task+"-dbr". To delete a restore task, specify the request name in the following format: ApplicationRestore name of the restore task+"-dbr".
   deleteObjectName	Yes	The name of the resource to be deleted.
   deleteObjectType	Yes	The type of resource to be deleted. Valid values: "Backup": deletes the ApplicationBackup resource of the backup task and the related resources. "Restore": deletes the ApplicationRestore resource of the restore task and the related resources. Note Deleting backup tasks does not affect the backups that are created in the cluster. Deleting restore tasks does not affect the data that is restored.

2. Run the following command in the cluster where you want to delete the task to deploy the deleterequest request.

   kubectl apply -f deleterequest.yaml

3. Run the following commands to check the resource status:

   • Check The Deleted Backup Task

     • Run the following command to query the status of the backup task:

       kubectl get applicationbackup <yourApplicationBackupName> -n csdr

       Expected result:

       Error from server (NotFound): applicationbackups.csdr.alibabacloud.com "yourApplicationBackupName" not found

       The output indicates that the backup task resources are deleted.

     • Run the following command to query the status of the deleterequest resources:

       kubectl get deleterequest <yourApplicationBackupName-dbr> -n csdr

       Expected result:

       Error from server (NotFound): deleterequests.csdr.alibabacloud.com "yourApplicationBackupName-dbr" not found

       The output indicates that the deleterequest resources are also deleted.

   • Check The Deleted Restore Task

     • Run the following command to query the status of the restore task:

       kubectl get applicationrestore <yourApplicationRestoreName> -n csdr

       Expected result:

       Error from server (NotFound): applicationrestores.csdr.alibabacloud.com "yourApplicationRestoreName" not found

       The output indicates that the restore task resources are deleted.

     • Run the following command to query the status of the deleterequest resources:

       kubectl get deleterequest <yourApplicationRestoreName-dbr> -n csdr

       Expected result:

       Error from server (NotFound): deleterequests.csdr.alibabacloud.com "yourApplicationRestoreName-dbr" not found

       The output indicates that the deleterequest resources are also deleted.

References

• For more information about how to back up and migrate applications in the console, see the following topics:

  • Back up and restore applications within a cluster

  • Migrate applications across clusters within the same region

  • Migrate applications across clusters in different regions

• For more information about how to migrate applications across storage plug-ins and across clusters of different versions, see Use the backup center to migrate applications from earlier Kubernetes versions.

• Use Terraform to back up and restore applications