Kubernetes

Every ship has a captain, which manages all activities on a ship. Captain indicates they are interested in joining the group. The captain of the ship is the kubelet A kubelet is an agent that runs on each node in a cluster. It listens for instructions from the Kobe API and deploys or destroys containers on the nodes as required. Kube api server will periodically fetch status reports from kubelet.

Imperative vs Declarative

• Imperative: What to do, and HOW to do it (Turn left at the next intersection). Written instructions step by step.

  kubectl run/create/expose (create new) kubectl edit/scale/set (update existing)

• Declarative: “Drive to Tom’s House”. Kubernetes figure out HOW to do it. Infrastructure as Code kubectl replace -f, create -f, apply -f (path or directory)