kube-controller-manager

Component responsible for operating cluster controllers

Logically, each controller is a separate process, but to reduce complexity, they are all compiled into a single binary and run in a single process.

Node Controller

Responsible for noticing and responding when nodes go down.

Replication Controller

Responsible for maintaining the correct number of pods for every replication controller object in the system.

Endpoints Controller

Populates the Endpoints object (that is, joins Services & Pods).

Service Account & Token Controllers

Create default accounts and API access tokens for new namespaces.