Migrate an App from one cluster to another

07/26/2024 Contributors

Velero’s backup and restore capabilities make it a valuable tool for migrating your data between clusters. This section describes how to migrate apps(s) from one cluster to another by creating a backup of the app in Object storage from one cluster and then restoring the app from the same object storage to another cluster. .

Backup from first cluster

Prerequisites on Cluster 1

Astra Trident must be installed on the cluster.
A trident backend and Storage class must be created.
OADP operator must be installed on the cluster.
The DataProtectionApplication should be configured.

Use the following spec to configure the DataProtectionApplication object.

spec:
  backupLocations:
    - velero:
        config:
          insecureSkipTLSVerify: 'false'
          profile: default
          region: us-east-1
          s3ForcePathStyle: 'true'
          s3Url: 'https://10.61.181.161'
        credential:
          key: cloud
          name: ontap-s3-credentials
        default: true
        objectStorage:
          bucket: velero
          caCert: <base-64 encoded tls certificate>
          prefix: container-backup
        provider: aws
  configuration:
    nodeAgent:
      enable: true
      uploaderType: kopia
    velero:
      defaultPlugins:
        - csi
        - openshift
        - aws
        - kubevirt

Create an application on the cluster and take a backup of this application.
As an example, install a postgres application.

Use the following spec for the backup CR:

spec:
  csiSnapshotTimeout: 10m0s
  defaultVolumesToFsBackup: false
  includedNamespaces:
    - postgresql
  itemOperationTimeout: 4h0m0s
  snapshotMoveData: true
  storageLocation: velero-sample-1
  ttl: 720h0m0s

You can click on the All instances tab to see the different objects being created and moving through different phases to finally come to the backup completed phase.

A backup of the resources in the namespace postgresql will be stored in the Object Storage location (ONTAP S3) specified in the backupLocation in the OADP spec.

Restore to a second cluster

Prerequisites on Cluster 2

Astra Trident must be installed on cluster 2.
The postgresql app must NOT be already installed in the postgresql namespace.
OADP operator must be installed on cluster 2, and the BackupStorage Location must be pointing to the same object storage location where the backup was stored from the first cluster.
The Backup CR must be visible from the second cluster.

backup storage location pointing to the same object store

Restore the app on this cluster from the backup. Use the following yaml to create the Restore CR.

apiVersion: velero.io/v1
kind: Restore
apiVersion: velero.io/v1
metadata:
  name: restore
  namespace: openshift-adp
spec:
  backupName: backup
  restorePVs: true

When the restore is completed, you will see that the postgresql app is running on this cluster and is associated with the pvc and a corresponding pv. The state of the app is the same as when the backup was taken.

Migrate an App from one cluster to another

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