id: controller
name: Controller
full-link: /docs/admin/kube-controller-manager/
related:
- controller-manager
tags:
- architecture
- fundamental
short-description: >
  A control loop that watches the shared state of the cluster through the {% glossary_tooltip text="apiserver" term_id="kube-apiserver" %} and makes changes attempting to move the current state towards the desired state.
long-description: >
  Examples of controllers that ship with Kubernetes today are the replication controller, endpoints controller, namespace controller, and serviceaccounts controller.