Admission controller is what allows us make API request to Kubernetes. After authentication and Authorization are passed, the Admission control attends to request. It allows us access the content of objects in a request. The admission controller can be enabled by passing the –admission-control in versions before 1.10 and –enable-admission-plugins parameter in version 1.10 and later to the API server or modifying the kubernetes api-server configuration file. The Admission controller can deny and validate or modify the content of a request. Example of controllers manage by Admission controller that come by default in kubernetes release v1.9 are as follows.
the order os Admission Controllers in the list matters.