Prerequisites

Where you are

Before you build a cluster, you need to know what you are building it on. This step sets the target: four machines, their specs, and how they relate to each other. You decide the shape of the ground first so that every later step has a known place to land. Settle the machines and the operating system now, and the rest of the course has a stable base to build on.

Machines you need

This course uses four machines running Debian 12 (bookworm) on ARM64 or AMD64. The table below lists each machine and its CPU, memory, and storage.

This is a minimal production topology: one control-plane machine (server) and two workers (node-0 and node-1), all driven from a single administration host (jumpbox). You run commands from the jumpbox and reach the other three over the network.

How you provision the machines is up to you. The only requirement is that each machine meet the specs and operating system version above. This is a local-first course, so the recommended path is to create the four Debian 12 ARM64 machines on your own Mac with Apple Silicon using Multipass. The step-by-step machine-creation instructions live in appendix/local-first-multipass.md. Follow that appendix to bring up all four machines, then return here to verify them.

Once you have all four machines provisioned, verify the OS requirements by viewing the /etc/os-release file:

cat /etc/os-release

You should see something similar to the following output:

PRETTY_NAME="Debian GNU/Linux 12 (bookworm)"
NAME="Debian GNU/Linux"
VERSION_ID="12"
VERSION="12 (bookworm)"
VERSION_CODENAME=bookworm
ID=debian

Run this check on each of the four machines. If a machine reports a different OS or version, fix it before moving on.

Key terms

• Jumpbox: the administration host you run commands from. It holds your tools and reaches the other machines over the network.
• Control plane: the part of Kubernetes that makes cluster-wide decisions and tracks state. In this course it runs on the machine named server.
• Worker node: a machine that runs your application containers. Here those are node-0 and node-1.
• Topology: the set of machines and how they connect. This course uses one control-plane machine and two workers, driven from a jumpbox.
• Multipass: a tool that creates and manages lightweight virtual machines on your Mac. You use it to make the four Debian machines locally.

Reflect

If you later wanted to add a third worker, what would you check on the new machine before joining it to the cluster?

Next: Set up the jumpbox