Unable to Add Additional Webhooks Without Forcing Re-scaffold

[camilamacedo86]

What broke? What's expected?

When trying to add an additional webhook (e.g., conversion webhook) to an API where other webhooks (like defaulting or validation) are already scaffolded, Kubebuilder throws an error stating that the webhook files already exist. Currently, the only workaround is to use the --force option, which leads to the entire webhook being re-scaffolded, overwriting any custom implementation added by the user. This behavior results in lost code and makes it difficult to incrementally add webhooks.

Kubebuilder should allow adding additional webhooks without forcing the user to use --force and without overwriting existing implementation. It should:

• Detect existing webhooks.
• Ensure appropriate markers are present.
• Scaffold only the necessary webhook logic (e.g., for conversion, validation, or defaulting) specific to the new request, preserving existing code.

Such as we do in the main.go and for the test-e2e as well. See the WebhookTestUpdater for test-e2e. We need ensure that webhooks follow the same: https://github.com/kubernetes-sigs/kubebuilder/blob/master/pkg/plugins/golang/v4/scaffolds/internal/templates/test/e2e/test.go#L58-L103

Reproducing this issue

• 1. Scaffold an API with defaulting and validation webhooks:

kubebuilder create api --group batch --version v1 --kind CronJob --resource=true --controller=true
kubebuilder create webhook --group batch --version v1 --kind CronJob --defaulting --programmatic-validation

• 2. Try adding a conversion webhook for the same API and kind:

kubebuilder create webhook --group batch --version v1 --kind CronJob --conversion

• 3. You’ll encounter an error indicating that the webhook files already exist.
• 4. The only option to proceed is to use --force, which will remove the current webhook implementation:

kubebuilder create webhook --group batch --version v1 --kind CronJob --conversion --force

• 5. The --force option re-scaffolds the entire webhook, leading to the loss of any custom code previously added to the webhook.

Expected Behavior/Request Kubebuilder should scaffold only the specific webhook (e.g., conversion) requested without overwriting the existing webhook code. It should intelligently detect existing webhooks and add the necessary logic for the new type while keeping the current implementation intact.

KubeBuilder (CLI) Version

4.2.0

PROJECT version

No response

Plugin versions

No response

Other versions

No response

Extra Labels

No response

[fischor]

/assign
Would like to start once #4150 is merged