In Kubernetes, the control plane manages the worker nodes and the Pods in the cluster. The control plane is responsible for ensuring your clusters run the way you have configured them.
Components of the control plane include the kube-apiserver, etcd, kube-scheduler, kube-controller-manager, and the cloud-controller-manager. These components manage your Kubernetes cluster, including cluster state and configuration.
Stuff you wanna know:
- The control plane components communicate with the cluster apiserver over the secure port.
- There are two primary communication paths from the control plane (apiserver) to the nodes. The first is from the apiserver to the kubelet process which runs on each node in the cluster. The second is from the apiserver to any node, pod, or service through the apiserver’s proxy functionality.
- In production environments, the control plane usually runs across multiple computers and a cluster usually runs multiple nodes, providing fault-tolerance and high availability.
More stuff:
- https://kubernetes.io/docs/concepts/architecture/control-plane-node-communication/
- https://sysdig.com/blog/monitor-kubernetes-control-plane/
- https://cloud.google.com/kubernetes-engine/docs/concepts/cluster-architecture
- https://www.redhat.com/sysadmin/kubernetes-components
- https://www.cncf.io/blog/2021/08/20/how-to-secure-your-kubernetes-control-plane-and-node-components/
- https://docs.oracle.com/en-us/iaas/Content/ContEng/Concepts/contengclustersnodes.htm
- https://cluster-api.sigs.k8s.io/developer/architecture/controllers/control-plane.html
- https://medium.com/analytics-vidhya/the-kubernetes-control-plane-f4bf460c848f
- https://github.com/kelseyhightower/kubernetes-the-hard-way/blob/master/docs/08-bootstrapping-kubernetes-controllers.md
- https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/high-availability/
