kubelet

• kubelet is the agent that runs on each node of the cluster (workers and masters)
• Attributions
• Register a new node within the Kubernetes cluster
• Create pods

• Monitor nodes & pods (ensure it's running properly)

• It listens instructions from the API server (E.g, deploy, destroy containers)

• kube-apiserver periodically fetches status report from the kubelet

Static Pods

• kubelet continues to function even without the master node or any other worker nodes
• Without a master node, it has node connection with the kube-apiserver and therefore cannot receive instructions
• The kubelet can however create static pods by constantly reading manifests from a local directory /etc/kubernetes/manifests
• This path is defined by the pod-manifest-path parameter
• Or by specifying it in the config.yaml file (defined in the config parameter) with the staticPodPath option
• Static pods are also mirrored as objects in the kube-apiserver.
• Mirrored objects are read-only and cannot be updated or deleted
• Static pods can only be modified by means of the manifest folder
• Static pods are used to deploy the control plane components itself. As pods! (not conventional services). That's how kubeadm set up the cluster
• That's why pods in kube-system namespace are shown, they are only mirrors to static the pods