Kubebuilder: Don't recommend using manager.GetClient in tests

[moolen]

Using the manager.GetClient() in tests is a bad idea and should not be recommended by the documentation. The manager's client is a cached client.Reader which is fine for a controller - but in tests you probably want a strongly consistent client.

This is the documentation i am referring to:
https://github.com/kubernetes-sigs/kubebuilder/blame/master/docs/book/src/cronjob-tutorial/testdata/project/controllers/suite_test.go#L115-L116

There's an older issue that explains the problem in more detail: https://github.com/kubernetes-sigs/controller-runtime/issues/343

I'd suggest updating the documentation about that. What do you think? Did anybody else run into that issue yet?

/kind bug
/kind documentation

[Adirio]

Any help with the documentaiton is appreciated
/help
/good-first-issue

P.S.: the most relevant part of the linked conversation is https://github.com/kubernetes-sigs/controller-runtime/issues/343#issuecomment-469435686

[k8s-ci-robot]

@Adirio:
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In response to this:

Any help with the documentaiton is appreciated
/help
/good-first-issue

P.S.: the most relevant part of the linked conversation is https://github.com/kubernetes-sigs/controller-runtime/issues/343#issuecomment-469435686

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[Adirio]

/remove-kind bug

[leovct]

Hello @Adirio, I would like to contribute to the project by working on this issue :)

[Adirio]

Sure, help is always apreciated. Feel free to submit a PR and assign me so that I can review it.

[leovct]

/assign

[DirectXMan12]

To be clear for posterity (because the follow-up PR broke the tests): You shouldn't use the manager's client in assertions in tests. You should use the manager's client in your reconciler.