fix(grpc-route-match): allow undefined rpc match in MatchRoute defini…

[anthoturc]

…tion

fixes linkerd/linkerd2#14047

[cratelyn]

i see there are some open questions in #14047, here: linkerd/linkerd2#14047 (comment). have we confirmed for sure that this addresses the reported issue? it isn't completely clear to me right now if this is ready to be reviewed.

[cratelyn]

also, noting that we'll need to add sign-off information to the commits in this branch.

[cratelyn]

left some comments above...

[anthoturc]

i see there are some open questions in #14047, here: linkerd/linkerd2#14047 (comment). have we confirmed for sure that this addresses the reported issue? it isn't completely clear to me right now if this is ready to be reviewed.

Ah yes, this is a question for the person who set published an image for the repro. I wasn't sure if there was a typo in the print statements of the client application.

By any chance is there a typo in the print statements within the image? The logs in service-a didn't look quite right.

My end-to-end test included TAPping the client/servers and suggested that the fix does address the underlying issue.

I'll DM you to discuss this a little further.

[anthoturc]

also @cratelyn, i did run the linkerd2 integration tests with the proxy image built from this commit and the same tests pass against main and this branch.

there was one failing test across main and my branch that failed, but it looked related to my setup as opposed to some business logic:

install_test.go:687: Error retrieving resource requirements for linkerd-destination: container linkerd-proxy not found in deployment linkerd-destination in namespace linkerd
  --- FAIL: TestComponentProxyResources (0.00s)
  FAIL
  FAIL    command-line-arguments    131.903s
  FAIL
  Error: uninstall: Release not loaded: multicluster-test: release: not found
  Error from server (NotFound): namespaces "linkerd-multicluster" not found
  release "helm-test-l5d-viz" uninstalled
  namespace "linkerd-viz" deleted
  release "helm-test-control-plane" uninstalled
  release "helm-test-crds" uninstalled
  namespace "linkerd" deleted

everything else passed so i think we should be okay with merging