Admission controller is a piece of code that intercepts requests to Kubernetes API server prior to persistence of the object, but after the request is authenticated and authorized.
Admission controller can mutate or reject specific requests based on some criteria. Admission webhooks are dynamic HTTP callbacks that receive the Kubernetes API admission requests and do something with them (e.g., modify or reject to enforce custom policies).
In this session, Liron Levin will talk through how to write and deploy a validating admission webhook from scratch in GO.