Backup and Restore Workloads using KubeStash

This guide will show you how KubeStash backs up and restores volumes of various workload types (Deployment, StatefulSet, DaemonSet etc.).

Before You Begin

• You should be familiar with the following KubeStash concepts:
  • BackupConfiguration
  • BackupSession
  • RestoreSession
  • BackupStorage

How Backup Process Works

The following diagram shows how KubeStash takes backup of the volumes of a workload. Open the image in a new tab to see the enlarged version.

The backup process consists of the following steps:

1. At first, a user creates a Secret. This secret holds the credentials to access the backend where the backed up data will be stored.

2. Then, she creates a BackupStorage custom resource that specifies the backend information, along with the Secret containing the credentials needed to access the backend.

3. KubeStash operator watches for BackupStorage custom resources. When it finds a BackupStorage object, it initializes the BackupStorage by uploading the metadata.yaml file into the target storage.

4. Then, she creates a BackupConfiguration custom resource that specifies the targeted workload, the Addon info with a specified task, etc. It also provides information about one or more repositories, each indicating a path and a BackupStorage for storing the backed-up data.

5. KubeStash operator watches for BackupConfiguration objects.

6. Once the KubeStash operator finds a BackupConfiguration object, it creates Repository with the information specified in the BackupConfiguration.

7. KubeStash operator watches for Repository custom resources. When it finds the Repository object, it Initializes Repository by uploading repository.yaml file into the spec.sessions[*].repositories[*].directory path specified in BackupConfiguration.

8. Then, it creates a CronJob for each session with the schedule specified in BackupConfiguration to trigger backup periodically.

9. On the next scheduled slot, the CronJob triggers a backup by creating a BackupSession custom resource.

10. KubeStash operator watches for BackupSession custom resources.

11. When it finds a BackupSession object, it creates a Snapshot custom resource for each Repository specified in the BackupConfiguration.

12. Then it resolves the respective Addon and Function and prepares backup Job(s) definition.

13. Then, it mounts the targeted workload volume(s) into the Job(s) and creates it/them.

14. The Job(s) takes backup of the targeted workload.

15. After the backup process is completed, the backup Job updates the status.components[*] field of the Snapshot resources with backup information of the target application components.

How Restore Process Works

The following diagram shows how KubeStash restores backed up data inside a workload. Open the image in a new tab to see the enlarged version.

The restore process consists of the following steps:

1. At first, the user creates a workload where the data will be restored or the user can use the same workload.

2. Then, she creates a RestoreSession custom resource that specifies the target workload volume(s) where the backed-up data will be restored, the Repository object that points to a BackupStorage that holds backend information, and the target Snapshot, which will be restored. It also specifies the Addon info with task to use to restore the volume.

3. KubeStash operator watches for RestoreSession custom resources.

4. When it finds a RestoreSession custom resource, it resolves the respective Addon and Function and prepares a restore Job(s) definition.

5. The restore Job(s) restores the backed-up data into the targeted workload volume(s).

6. Finally, when the restore process is completed, the Job(s) updates the status.components field of the RestoreSession to reflect restore process.

Next Steps

1. See a step by step guide to backup/restore volumes of a Deployment here.
2. See a step by step guide to backup/restore volumes of a StatefulSet here.
3. See a step by step guide to backup/restore a DaemonSet’s volumes here.