Design doc for delete associated backup and restic repos when BSL is deleted (#4297)

* Update EnableAPIGroupVersion feature design doc as implemented

Signed-off-by: F. Gold <fgold@vmware.com>

* Design doc for issue 2082 to delete associated resources when deleting BSLs

Signed-off-by: F. Gold <fgold@vmware.com>

* Changes per @dsu-igeek review comments

Signed-off-by: F. Gold <fgold@vmware.com>

design/2082-bsl-delete-associated-resources_design.md

@@ -0,0 +1,40 @@
+# Delete Backup and Restic Repo Resources when BSL is Deleted
+
+## Abstract
+
+Issue #2082 requested that with the command `velero backup-location delete <bsl name>` (implemented in Velero 1.6 with #3073), the following will be deleted:
+
+- associated Velero backups (to be clear, these are custom Kubernetes resources called "backups" that are stored in the API server)
+- associated Restic repositories (custom Kubernetes resources called "resticrepositories")
+
+This design doc explains how the request will be implemented.
+
+## Background
+
+When a BSL resource is deleted from its Velero namespace, the associated custom Kubernetes resources, backups and Restic repositories, can no longer be used.
+It makes sense to clean those resources up when a BSL is deleted.
+
+## Goals
+
+Update the `velero backup-location delete <bsl name>` command to delete associated backup and Restic repository resources in the same Velero namespace.
+
+## Non Goals
+
+[It was suggested](https://github.com/vmware-tanzu/velero/issues/2082#issuecomment-827951311) to fix bug #2697 alongside this issue.
+However, I think that should be fixed separately because although it is similar (restore objects are not being deleted), it is also quite different.
+One is adding a command feature update (this issue) and the other is a bug fix and each affect different parts of the code base.
+
+## High-Level Design
+
+Update the `velero backup-location delete <bsl name>` command to do the following:
+
+- find in the same Velero namespace from which the BSL was deleted the associated backup resources and Restic repositories, called "backups.velero.io" and "resticrepositories.velero.io" respectively
+- delete the resources found
+
+The above logic will be added to [where BSLs are deleted](https://github.com/vmware-tanzu/velero/blob/main/pkg/cmd/cli/backuplocation/delete.go).
+
+## Alternative Considered
+
+I had considered deleting the backup files (the ones in json format and tarballs) in the BSL itself.
+However, a standard use case is to back up a cluster and then restore into a new cluster.
+Deleting the backup storage location in either location is not expected to remove all of the backups in the backup storage location and should not be done.

design/Implemented/restore-with-EnableAPIGroupVersions-feature.md

@@ -1,6 +1,6 @@
 # Restore API Group Version by Priority Level When EnableAPIGroupVersions Feature is Set
 
-Status: Draft
+Status: Accepted
 
 ## Abstract