Intermittent errors from packagevariant

[JagratiS]

Expected behavior

Actual behavior

Intermediate errors are coming before ensured package by packagevariant in downstream repo

Information

Errors -

System -
vm - ubuntu
cluster - Kind cluster
kpt version - 1.0.0-beta.44
flux version - flux version 2.1.1
porch - v0.0.27

kubectl get packagevariant test -o yaml

message: 'Internal error occurred: package revision workspaceNames must be unique;
        package revision with name nginxv4-france in repo package-nif-intent with
        workspaceName packagevariant-108 already exists'

message: 'Internal error occurred: Operation cannot be fulfilled on packagerevisionresources.porch.kpt.dev
      "rom-package-variant-1e45707782d551a7284247b086057c20f270cfa9": the object has
      been modified; please apply your changes to the latest version and try again'

After these errors it got success.

kpt alpha rpkg get
test-downstream-repo-a58ef0ad235bee2a5a7670e3e9c1a88b871d8a1f   nginxv1-test   packagevariant-6    main       false    Published   test-downstream-repo
test-upstream-repo-b9b9fb6aa0072054f66a072bccf72bb96b8cfe08     nginx            pv-1                main       false    Published   test-upstream-repo
test-upstream-repo-6fa7341e4e3be245a24af99849b744b2369f371d     nginx            pv-1                v1         true     Published   test-upstream-repo

Can you share any details regarding these errors or is there any issue with my setup?

Steps to reproduce the behavior

[johnbelamaric]

Thanks for the bug report.

In a recent release, we added standard K8s optimistic concurrency controls through proper use of ResourceVersion. That's the second error you are seeing; it indicates that some other client modified the package since you read it. When this happens in PV, the reconciliation loop will try again after a bit; so, it should clear itself up.

That said, we shouldn't see this error as frequently as we do. I think there are a couple possible things we should check:

• We should make sure that the ResourceVersion being reported for the PackageRevision is the commit hash of the draft branch, or in the case of a Published package, of the tag. If instead it is using the commit hash of HEAD, that could cause this issue if a different package in the same repo were changed. It would probably cause other issues too.
• Alternatively, it could be that somehow something else is editing the package draft even before the packagevariant gets to it. This could be the nephio-controllers, if you are running this in Nephio. If you are not, then it's not clear what's going on. Looking at the Git history for the package directory may give us a hint, and/or at the PackageRevision task list. Or, do you have another controller running that may be operating on Draft packages?

The first error

        package revision with name nginxv4-france in repo package-nif-intent with
        workspaceName packagevariant-108 already exists

seems to indicate that the second explanation is more likely - it's almost like the PV controller is trying to process it twice, concurrently, with some race condition (the workspace name is generated by the PV controller here: https://github.com/kptdev/kpt/blob/main/porch/controllers/packagevariants/pkg/controllers/packagevariant/packagevariant_controller.go#L645 - that function is called in two places).