Webhooks are requests for information sent in a blocking fashion. A web application implementing webhooks will send a HTTP request to other applications when a certain event happens.
In the kubernetes world, there are 3 kinds of webhooks: admission webhook, authorization webhook and CRD conversion webhook.
In controller-runtime libraries, we support admission webhooks and CRD conversion webhooks.
Kubernetes supports these dynamic admission webhooks as of version 1.9 (when the feature entered beta).
Kubernetes supports the conversion webhooks as of version 1.15 (when the feature entered beta).