Facilitate the config on the scaffolding when only validation OR Mutation Webhooks are used

[camilamacedo86]

What broke? What's expected?

When attempting to scaffold only ValidatingWebhooks in a new kubebuilder project, I encountered an issue where MutatingWebhookConfiguration references still cause errors, despite ensuring that all related configuration for MutatingWebhookConfiguration is commented out or removed. Also, see that we just scaffold MutatingWebhookConfiguration when the flag --defaulting is used. Then, note that the cert-manager configuration is not working well with only one of the cases scenarios. See that for example, for we run and test our e2e scaffolded for the sample we need to use both flags to make it work: https://github.com/kubernetes-sigs/kubebuilder/pull/4118/files

I expected be able to configure the default scaffold ONLY with validation webhooks and without defaulting/mutation. The scaffold should help and allow users be able to configure only one of them and work well in this case. We need to check what changes is required to do for each case scenario and ensure that the scaffolds can easily configured by users in thoses cases.

Reproducing this issue

1. Initialize a new Kubebuilder project:

   kubebuilder init --domain testproject.org --repo sigs.k8s.io/test

2. Create a new API:

kubebuilder create api --group ship --version v1beta1 --kind Frigate

3. create the webhook

kubebuilder create webhook --group ship --version v1beta1 --kind Frigate --programmatic-validation

4. Uncomment relevant sections in config/default/kustomization.yaml to enable cert-manager

NOTE: Indeed if I only uncomment all that is required only for ValidationConfig I still facing the issue

5. Generate the manifests and kustomize

make generate
make manifests
make build-installer

Error

Error: no resource matches strategic merge patch "MutatingWebhookConfiguration.v1.admissionregistration.k8s.io/mutating-webhook-configuration.[noNs]": no matches for Id MutatingWebhookConfiguration.v1.admissionregistration.k8s.io/mutating-webhook-configuration.[noNs]; failed to find unique target for patch MutatingWebhookConfiguration.v1.admissionregistration.k8s.io/mutating-webhook-configuration.[noNs]
make: *** [build-installer] Error 1

What is expected to get done in this task

• We need to figure out what is the configuration required for ONLY Validation OR for ONLY Multation
• We need to ensure that the scaffold provide can work with only one of the case scenarios
• We need to ensure that users are properly guide via scaffold comments to know what to do and when
• We need to have tests to ensure that configure only one of them will work fine

KubeBuilder (CLI) Version

master

PROJECT version

4.2.0

Plugin versions

go/v4
kustomize/v2

Other versions

No response

Extra Labels

No response