Control Plane
- It manages the whole cluster.
- It manages the health check of the working nodes and shows information of member of cluster.
- Communicates with working nodes to ensure that all the application is running properly.
COMPONENTS OF CONTROL PLANE
1. etcd - It stores the current state of the cluster.
2. API server
- CRUD operations for server go through API.
- Kubectl takes command and forward to API server to perform the operation.
3. Scheduler
- It schedules the pods accordingly.
- Basically scheduler looks for appropriate nodes that meets the user criteria and schedules the pod accordingly.
4. Controller Manager
- It manages the controller.
It basically have three functionality
- Check current state
- Check desired state
- Check differences and make the changes
Working Nodes
It is a physical layer where deployment of containers takes place.
COMPONENTS OF WORKING NODES
1. Kubelet
- Ensures that the containers described in pod spec is working and running healthy.
- Incase Kubelet notices any issue with the pods running on worker nodes, it tries to restart the pod at the same node.
- If the fault is the worker node itself, then it recreates the pods with healthy worker nodes.
1. Kube-proxy
- It maintains the network configuration.
- provides IP address to nodes.
- Maintains the distributed networks across nodes, pods and containers.
