exploring kubernetes - the control plane

overview

In kubernetes the control plane is what manages the worker nodes and pods that run in our cluster. The control plane is responsible for global decision as well as detecting and responding to cluster events. The control plane components can be ran on any machine in the cluster, but setup scripts typically start all components on the same machine. It is important that we do not run user conatiner on the same machine that is running the control plane components. There are 5 components that make up the control plane: kube-apiserver, etcd, kube-scheduler, kube-controller-manager, cloud-controller-manager

kube-apiserver

The kube-apiserver is the kubernetes contol plane component that exposes the kubernetes api server. One thing to note is that is sales horizontally, which means it scales by deploying more instances

etcd

Key-Value store that is used as kubernetes badcking store for cluster data.

kube-scheduler

the kube-scheduler components watches new created pods and scheduled them to a node

kube-controller-manager

the kube-controller-manager is the control plane that runs the controller process.

cloud-controller-manager

The cloud-controller-manager is the control plane componenet tha tembeds cloud-specific control logic. This component allows you rcluster to link the cloud proider's api.