a) kube-apiserver

• Server of Api’s
• Front end to the Master Node
• Any request from Inside or outside the kubernetes is received by API server
• Exposes the REST API
• Consumes JSON (via manifest file)

b) Cluser store

• Persist storage for cluster state and config
• Uses etcd to manage

c) Kube-Controller-Manager

• Manager/Controller of Controllers such as Node Controller, Endpoint controller, Namespace controller etc
• Watches the changes in API Server
• Helps maintain the desired state

d) Kube-scheduler

• Watches apiserver for new pods
• Schedule Pods
• Assigns work to nodes
• Respect constrains

e) kubectl

• Communicate to Kube-apiserver using JSON
• Can give desired state of container/pod in YAML/JSON