Exploring the Components That Constitute the Cluster

Exploring the constituents of the cluster

When kops created the VMs (EC2 instances), the first thing it did was to execute nodeup. It, in turn, installed a few packages. It makes sure that Docker, Kubelet, and Protokube are up and running.

Docker

Docker runs containers.

Kubelet

Kubelet is Kubernetes’ node agent. It runs on every node of a cluster, and its primary purpose is to run Pods. To be more precise, it ensures that the containers described in PodSpecs are running as long as they are healthy. It primarily gets the information about the Pods it should run through Kubernetes’ API server. As an alternative, it can get the information through files, HTTP endpoints, and HTTP servers.

Protokube

Unlike Docker and Kubelet, Protokube is specific to kOps. Its primary responsibilities are to discover and mount primary disks and create ...