Components of Kubernetes Cluster

19 Feb 2021

There are two components of a Kubernetes Cluster

  • Control Plane Components
  • Node Components

k8 cluster Reference: Overview Components

Control Plane Components

The control plane components make global decisions about the cluster, as well as detecting and responding to cluster events.

# Component Responsibility
1 kube-apiserver Exposes the Kubernetes API
2 etcd Consistent and highly-available key value store for storing all cluster data
3 kube-scheduler
  • selects node to run Pods
  • watches for newly created Pods
    		•
    4 kube-controller-manager
  • It runs different controller processes
  • Node controller
  • Job controller
  • Endpoints controller
  • Service Account & Token controllers
    		•
    5 cloud-controller-manager
  • It contains cloud provider specific control logic
  • Applications like minikube which are used for local setup will not have this component
    		•

    Node Components

    # Component Responsibility
    1 kubelet Ensures that containers are running in a pod, on each node of the cluster
    2 kube-proxy It maintains the network rules on the nodes of the cluster
    3 container-runtime software application responsible for running the containers
    4 Addons
  • DNS
  • Web UI
  • Container Resource Monitoring
    		•