day5: kubelet

Source: Dev.to

Overview

Kubelet acts like the captain of a ship in the Kubernetes analogy. It:

• Requests the paperwork needed to join the cluster.
• Serves as the sole point of contact from the master/control‑plane.
• Loads and unloads containers on the node as instructed by the Scheduler.
• Reports back on the status of both the node and its containers.

The Kubelet registers the worker node with a Kubernetes cluster. When it receives instructions to run a pod, it asks the container runtime to pull and run the specified image. It then continuously monitors the pod and its containers, sending status updates to the Kubernetes API server.

Think of the Kubelet as the node manager: it reports status to the API server, knows the state of all pods on the node, and instructs the container runtime accordingly.

Even when using the Kubernetes admin tools, the Kubelet must be manually installed on worker nodes—download the installer, extract it, and run it as a service.

Viewing the Kubelet Process

You can view the running Kubelet process and its options by searching for it on the worker node:

ps aux | grep kubelet