Add envtest example for CronJob controller

[hasbro17]

As I was reading the docs for envtest I see the following:

Until more documentation has been written, your best bet to get started is to look at some existing examples, such as:

• Azure Databricks Operator: see their fully fleshed-out suite_test.go as well as any *_test.go file in that directory like this one.

I assume more documentation probably meant the following sub-section that was added later on which covers the setup and configuration of envtest but references no example test for users to look at.
https://book.kubebuilder.io/reference/testing/envtest.html

While the Azure Databricks Operator example seems sufficient I was wondering if it would be beneficial to have a envtest example for the CronJob controller itself so that we have a canonical example to reference within the repo.

Low priority but I wanted to see if there's interest in this before trying to write any tests for the CronJob controller.

/kind documentation

[hasbro17]

/remove-kind feature

[hasbro17]

/cc @mengqiy

[gabbifish]

I’ve been working on docs for a generalized approach to envtest in the context of writing tests for the CronJob example :) Planning on opening a PR for it tomorrow morning, and I’ll reference it here. (It will be my first kubebuilder project PR so I will especially appreciate feedback/guidance on it).

[fejta-bot]

Issues go stale after 90d of inactivity.
Mark the issue as fresh with /remove-lifecycle stale.
Stale issues rot after an additional 30d of inactivity and eventually close.

If this issue is safe to close now please do so with /close.

Send feedback to sig-testing, kubernetes/test-infra and/or fejta.
/lifecycle stale

[gabbifish]

Entrypoint docs for envtest, in the context of the cronjob tutorial, were put into the production kubebuilder book with PR #1579. I think we can consider this issue closed :)

[gabbifish]

/close

[k8s-ci-robot]

@gabbifish: Closing this issue.

In response to this:

/close

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.