I wrote a whole bunch of words and code about learning how to build a small #Kubernetes cluster on top of #NixOS step-by-step:

https://stephank.nl/p/2025-11-17-a-small-vanilla-kubernetes-install-on-nixos.html

And you can spin it up in some QEMU VMs with only a couple of Nix commands:

https://codeberg.org/kosinus/nixos-kubernetes-experiment#readme