In Kubernetes, what is the primary responsibility of the kubelet running on each worker node?

The kubelet is the primary agent that runs on each worker node in a Kubernetes cluster. Its core responsibility is to communicate with the control plane's API server and ensure that the containers described in Pod specifications (PodSpecs) are running and healthy on its node. It manages the entire lifecycle of the containers on the node, including pulling images, starting and stopping containers, and reporting their status back to the control plane. It does not make scheduling decisions but executes the decisions made by the scheduler.

A: Persistent storage is managed by the persistent volume subsystem and storage drivers (CSI), not primarily by the kubelet. B: Cluster state is managed by etcd, and scheduling decisions are the exclusive responsibility of the kube-scheduler component. D: Internal DNS is typically handled by CoreDNS, and service traffic routing is managed by the kube-proxy on each node.

- Kubernetes Documentation, "Components of Kubernetes," Section: "Node Components > kubelet." It states, "An agent that runs on each node in the cluster. It makes sure that containers are running in a Pod."

- Kubernetes Documentation, "Concepts > Cluster Architecture > Nodes." This page details the role of the node and its components, clarifying that the kubelet is the agent responsible for managing Pods on that node as directed by the control plane.