Understanding the Kubernetes Control Plane 101

A layperson’s analogy for my layperson brain

Joe Cardillo
4 min readJan 29, 2022
Photo by Andy Li on Unsplash

Even though I’ve been working with Kubernetes for the better part of a year, I’ve only recently come across a helpful analogy for understanding the control plane in a way that makes sense in every day (layperson) terms.

It’s the Shipping Analogy. Perhaps more pertinent today with all the shipping delays going on. Either way, let’s dive in.

Ship analogy

There are two main parts to a Kubernetes cluster. The master node and the worker nodes.

The master node is like the dock, which is responsible for all the management, logistics, communications and operations of everything. It’s the control center. It’s where the magic happens.

The worker nodes are like the ships that come into dock to receive and transport containers.

Control Plane Components

There are various aspects to a dock’s operations that allow it to run smoothly. Let’s think of the dock as the master node.

etcd — The dock needs to store information (on paper or digitally) about the ships currently docked, or waiting to dock, what containers are on which ship, what time the containers were loaded, etc.