Restore an App from a backup

07/16/2024 Contributors

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This section describes how to restore apps(s) from a backup.

Prerequisites

To restore from a backup, let us assume that the namespace where the app existed got accidentally deleted.

Restore to the same namespace

To restore from the backup that we just created, we need to create a Restore Custom Resource (CR). We need to provide it a name, provide the name of the backup that we want to restore from and set the restorePVs to true. Additional parameters can be set as shown in the documentation. Click on Create button.

apiVersion: velero.io/v1
kind: Restore
apiVersion: velero.io/v1
metadata:
  name: restore
  namespace: openshift-adp
spec:
  backupName: backup-postgresql-ontaps3
  restorePVs: true

When the phase shows completed, you can see that the app has been restored to the state when the snapshot was taken. The app is restored to the same namespace.

Restore to a different namespace

To restore the App to a different namespace, you can provide a namespaceMapping in the yaml definition of the Restore CR.

The following sample yaml file creates a Restore CR to restore an App and its persistent storage from the postgresql namespace, to the new namespace postgresql-restored.

apiVersion: velero.io/v1
kind: Restore
metadata:
  name: restore-to-different-ns
  namespace: openshift-adp
spec:
  backupName: backup-postgresql-ontaps3
  restorePVs: true
  includedNamespaces:
  - postgresql
  namespaceMapping:
    postgresql: postgresql-restored

When the phase shows completed, you can see that the app has been restored to the state when the snapshot was taken. The App is restored to a different namespace as specified in the yaml.

Restore to a different storage class

Velero provides a generic ability to modify the resources during restore by specifying json patches. The json patches are applied to the resources before they are restored. The json patches are specified in a configmap and the configmap is referenced in the restore command. This feature enables you to restore using different storage class.

In the example below, the app, during deployment uses ontap-nas as the storage class for its persistent volumes. A backup of the app named backup-postgresql-ontaps3 is created.

Simulate a loss of the app by uninstalling the app.

To restore the VM using a different storage class, for example, ontap-nas-eco storage class, you need to do the following two steps:

Step 1

Create a config map (console) in the openshift-adp namespace as follows:
Fill in the details as shown in the screenshot:
Select namespace : openshift-adp
Name: change-ontap-sc (can be any name)
Key: change-ontap-sc-config.yaml:
Value:

version: v1
resourceModifierRules:
- conditions:
     groupResource: persistentvolumeclaims
     resourceNameRegex: "data-postgresql*"
     namespaces:
     - postgresql
  patches:
  - operation: replace
    path: "/spec/storageClassName"
    value: "ontap-nas-eco"

The resulting config map object should look like this (CLI):

This config map will apply the resource modifier rule when the restore is created. A patch will be applied to replace the storage class name to ontap-nas-eco for all persistent volume claims starting with rhel.

Step 2

To restore the VM use the following command from the Velero CLI:

#velero restore create restore1 --from-backup backup1 --resource-modifier-configmap change-storage-class-config -n openshift-adp

The app is restored in the same namespace with the persistent volume claims created using the storage class ontap-nas-eco.

Restore an App from a backup

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Prerequisites