Velero Operator restore charm pv

charm
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Restore charm PV

This guide describes how to back up and restore a Persistent Volume for a charm that stores some data in the PVC managed by Juju.

Requirements

  • A client charm that provides a backup configuration via the interface. For example, MinIO operator.
  • Charmed Velero deployed and configured.
  • The client charm is related to Charmed Velero.

The Juju feature is only available with export JUJU_DEV_FEATURE_FLAGS=k8s-attach-storage.

Set up the environment variables

Define these variables before running any commands:

CLIENT_MODEL="client-model"
CLIENT_APP="my-app"
CLIENT_ENDPOINT="velero-backup-config"

Create a backup for the client charm

juju switch velero
juju run velero-operator/0 create-backup target=${CLIENT_APP}:${CLIENT_ENDPOINT} model=$CLIENT_MODEL
juju run velero-operator/0 list-backups

Save the backup UID from the list-backups action for later use.

Prepare the client charm

juju switch $CLIENT_MODEL
juju scale-application $CLIENT_APP 0

juju storage
juju remove-storage ${CLIENT_APP}-data/<id>

Restore with Charmed Velero

juju switch velero
juju run velero-operator/0 list-backups
juju run velero-operator/0 restore backup-uid=<backup-uid>

Discover restored PVs

Confirm that the restored Persistent Volume (PV) still points to the old Persistent Volume Claim (PVC) and note the name of the restored PV:

kubectl get pv
kubectl get pv <pv-name> -o jsonpath='{.spec.claimRef.namespace}/{.spec.claimRef.name}{"\n"}'

Import restored PVs into Juju storage & Reattach

Import the restored PV using juju. <storage_name> is the charm’s storage (e.g., minio-data). The --force flag is required to change the PV’s Reclaim Policy to retain and set PV’s claimRef to null before attaching later.

juju import-filesystem kubernetes <pv_name> ${CLIENT_APP}-data --force

Reattach the restored PV by retrieving the new storage name from juju storage and adding it to the application unit. --attach-storage flag instructs Juju to create a new PVC and bind a PV to it.

juju add-unit $CLIENT_APP --attach-storage ${CLIENT_APP}-data/<id>

Check the application

Check the status of the application and confirm that the PVC was reattached:

juju status $CLIENT_APP
kubectl -n $CLIENT_MODEL get pvc
kubectl -n $CLIENT_MODEL describe pvc <claim>