Dataplane resources must be validated before being used in actual deployment in order to catch issues with configuration quickly before they cause runtime errors.

These checks should be implemented as webhooks, on levels of individual resources, and as checks within operators in case of configuration dependent on multiple resources, or multiple types of resources.

Webhooks should not require information about more than one instance of a specific resource to function. They must not implement k8s client or access resources other than those they are checking correctness of.

All checks must be implemented in accordance with current recommended practice for webhooks  for our project[0] and for k8s in general.
With deference to project practices when the two diverge.

[0]https://github.com/openstack-k8s-operators/docs/blob/596ce99df54a9b3f86b76c28b9a78af79dfe77db/webhooks.md?plain=1