The brain of the system that keeps track of all the other parts.
Review previous parts of this series for better understanding:
This is fifth part of the Kubernetes series. In this part I will try to add more insights into Kubernetes Controller.
What is a Controller in Kubernetes?
A Controller is a non-terminating loop that regulates the state of a system. It watches the state of the cluster, then make or request changes where needed. Each controller tries to move the current cluster state closer to the desired state. There are different types of controllers for specific purposes.
Kubernetes Control Plane
Kubernetes Control Plane is a collection of the Controllers. kube-apiserver, kube-controller-manager and kube-scheduler are the three critical processes that makes up the control plane. Nodes that runs these processes are called Master Node which are replicated for availability and redundancy.