Kubernetes – Control Manager

The Kubernetes Control Manager (also known as the Control Plane Manager) is a component of the Kubernetes control plane that manages the high-level control loops that govern the overall state of the cluster. It is responsible for ensuring that the desired state of the cluster is maintained, and for detecting and correcting any deviations from that state.

Here are some key features and responsibilities of the Kubernetes Control Manager:

Node controller: The Node controller manages the state of nodes in the cluster, including detecting and responding to node failures and performing actions such as evicting pods from failed nodes.
Replication controller: The Replication controller manages the state of replicas of pods in the cluster. It ensures that the desired number of replicas is running, and it can automatically scale the number of replicas up or down based on changes in demand.
Endpoint controller: The Endpoint controller manages the network endpoints associated with services in the cluster. It ensures that the correct endpoints are created and updated as pods are created and destroyed.
Service account and token controllers: The Service account and token controllers manage the lifecycle of service accounts and access tokens in the cluster. They create, delete, and rotate service accounts and tokens as needed.
Namespace controller: The Namespace controller manages the creation and deletion of namespaces in the cluster. It ensures that the correct permissions are applied to resources within each namespace.
Persistent volume controller: The Persistent volume controller manages the lifecycle of persistent volumes in the cluster. It ensures that volumes are provisioned, bound to pods, and released when no longer needed.

Overall, the Kubernetes Control Manager is responsible for managing the high-level control loops that ensure the overall state of the cluster is maintained. Its responsibilities range from node and pod management to service and namespace management, and it plays a critical role in the reliable operation of a Kubernetes cluster.