if no kubeconfig use inclusterconfig test

[vaikas]

If no kubeconfig is specified, try to use inclusterconfig.

Proposed Changes

Pre-review Checklist

• At least 80% unit test coverage
• E2E tests for any new behavior
• Docs PR for any user-facing impact
• Spec PR for any new API feature
• Conformance test for any change to the spec

Release Note

Docs

[knative-prow-robot]

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This pull-request has been approved by: vaikas

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[codecov]

Codecov Report

Merging #5603 (81bbe4c) into main (003a8a2) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main    #5603   +/-   ##
=======================================
  Coverage   82.79%   82.79%           
=======================================
  Files         199      199           
  Lines        6230     6230           
=======================================
  Hits         5158     5158           
  Misses        744      744           
  Partials      328      328           

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[vaikas]

Now fails with this:

=== RUN   TestDefaultBrokerWithManyTriggers/test_default_broker_with_many_attribute_and_extension_triggers
    test_runner.go:162: Couldn't initialize clients: unable to load in-cluster configuration, KUBERNETES_SERVICE_HOST and KUBERNETES_SERVICE_PORT must be defined

When trying to load the in-cluster. I'll keep playing.

[vaikas]

doh, of course it does because the tests do not run in the cluster.

[vaikas]

@benmoss @salaboy
Due to: knative/pkg#2191

And to enable those tests, the order is now:

1. Use kubeconfig
2. if that doesn't work, use inclusterconfig
3. if that doesn't work, use default location for kubeconfig.
   All the tests now pass, and I think the order above is what we wanted.

[salaboy]

@vaikas that is the correct order... When I was looking at the code that leads me to my previous PR, I assumed that this order is defined inside the knative client which does the same checks in the same order, and for some reason, these checks are repeated here. Hence I assumed that by removing the if for the default location the checks will be delegated internally to the client that was being created.
I am referring to the checks in here: https://github.com/knative/pkg/blob/main/environment/client_config.go#L54

Can we reuse these checks, so they are not duplicated in every module using pkg? (remember that I am super new with the project structure, so I might be missing something big here :)

[benmoss]

I just opened knative/pkg#2197, I think this is the right fix, now sure how to be 100% sure this works for in-cluster, but from reading the code in client-go it should.

[devguyio]

/lgtm