fix lookup of backup objects in the cluster

[nhudson]

With #1031 changes there is an error when looking up Backups with using a ListParam. This changes how we filter for volumeSnapshot method backups.

2024-11-04T18:05:45.955686Z ERROR reconciling object:reconcile:reconcile:cleanup_old_volume_snapshots: controller::cloudnativepg::retention::snapshots:63: Failed to list backups in namespace barely-permissive-deer: ApiError: field label not supported: spec.method: BadRequest (ErrorResponse { status: "Failure", message: "field label not supported: spec.method", reason: "BadRequest", code: 400 }) object.ref=CoreDB.v1alpha1.coredb.io/barely-permissive-deer.barely-permissive-deer object.reason=object updated trace_id=00000000000000000000000000000000 instance=barely-permissive-deer namespace=barely-permissive-deer retention_days=40

[jasonmp85]

What's the bug preventing the API filter from working?

Code change looks good to me for in-memory workaround, I'm just curious why it broke…

[nhudson]

What's the bug preventing the API filter from working?

Code change looks good to me for in-memory workaround, I'm just curious why it broke…

Great question. The spec.method field is not a field that ListParams supports to look up objects with. I knew this, but did it anyway and never thought about it until I saw the error.

The ListParams method only supports looking up valid labels or a selector from the metadata, not actual fields inside the API object.