The Kubernetes API server is responsible for every request. The extension point in the request life cycle in the API server is for dynamic admission control. The admission controller is one of the most important stages of the request life cycle, since it intercepts and checks whether a request should be approved or not.
For every API request, first of all, the requester is checked by authentication and authorization. Afterward, admission controllers are run and decide to approve or reject the request. Finally, validation steps are carried out, and the resulting objects are stored:
The dynamic part of admission control comes from the fact that they can be dynamically added, removed, or updated during the runtime of Kubernetes clusters. In addition to the built-in admission controllers, there are ways...