Avoid usage of newly deprecated webhook.Validator and webhook.Defaulter interfaces

[nathanperkins]

What do you want to happen?

In this controller-runtime issue, it was decided to deprecate the webhook.Validator and webhook.Defaulter interfaces, due to issues they cause with project upgrades by requiring controller-runtime import in API packages. Those functions are planned to be removed later.

We should update the Kubebuilder generated code and the docs to use admission.CustomValidator and admission.CustomDefaulter instead.

Jan 13th edit:

We also need to implement this interface outside of the API packages so that the API packages are not coupled with controller-runtime versions (see the issue above for context). The docs should be updated to warn the reader about the dangers of implementing this on the API types.

Extra Labels

No response

[nathanperkins]

cc: @alvaroaleman

[alvaroaleman]

Kubebuilder is a separate project owned by a different set of people.

/transfer kubernetes-sigs/kubebuilder

[k8s-ci-robot]

@alvaroaleman: Something went wrong or the destination repo kubernetes-sigs/kubernetes-sigs/kubebuilder does not exist.

In response to this:

Kubebuilder is a separate project owned by a different set of people.

/transfer kubernetes-sigs/kubebuilder

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.

[alvaroaleman]

/transfer kubebuilder

[nathanperkins]

@alvaroaleman thank you for moving this! I thought I made it in kubebuilder but I must have mixed my tabs up.

[camilamacedo86]

Thank you for raising this one.
It is very helpful.

It would be amazing if we could track issues to fix those breaking changes and desecrations in controller-runtime always.
Thank you for moving it @alvaroaleman !!!

[camilamacedo86]

What is required to do here:

1 - Replace Defaulter with CustomDefaulter - https://github.com/search?q=repo%3Akubernetes-sigs%2Fkubebuilder%20%20Defaulter&type=code
2 - Validator with CustomValidator - https://github.com/search?q=repo%3Akubernetes-sigs%2Fkubebuilder++Validator&type=code

The change must be done for the docs/examples and default scaffold for the go/v4 plugin only.
We also need to ensure that the example/tutorial works well with the new example and perform all required caveats if necessary to make it work with the interface.

TIP Please, change first the default scaffold under pkg/plugins/golang/v4/ (i.e.

kubebuilder/pkg/plugins/golang/v4/scaffolds/internal/templates/api/webhook.go

Line 115 in 42c5220

var _ webhook.Defaulter = &{{ .Resource.Kind }}{}

) and run make generate then, see that the code used in the tutorial as the samples under testdata will be automatically updated with the latest changes. Then, after that ensure that the documentation and steps are either valid after the changes and supplement it as fit.

[jonas-jonas]

Hi, would love to provide a PR for this, if it's not yet taken. Looking at your comment @camilamacedo86 and the code base, it seems like a pretty straight forward change.

However, there haven't been any changes to the generated files since last year, meaning all generated files will be touched (2023 -> 2024). Would be happy to provide a separate PR just updating the timestamps if that better suits the workflow here. Let me know what you prefer.