What is the function of the controller manager in a Kubernetes environment?

The controller manager plays a crucial role in a Kubernetes environment by regulating the desired state of the cluster. It is responsible for managing various controllers that operate within the cluster. Each controller is tasked with ensuring that specific components of the cluster are running as intended. For instance, the replication controller manages the number of pod replicas, and the deployment controller manages the deployment of applications.

By continuously monitoring the current state of the cluster and comparing it to the desired state, the controller manager takes action when discrepancies are found. This can involve starting new pods, terminating unnecessary ones, or performing other necessary adjustments to maintain the health and stability of the cluster. This continuous adjustment and oversight are vital for maintaining the overall availability and performance of applications running in Kubernetes.

The other options describe functionalities that do not align with the specific responsibilities of the controller manager.