Comment by isityettime

For Nixers, this isn't painful; it's magical! :'D

One of the great joys of NixOS is that configuration of existing features is continuous with development of new features. Both are just NixOS modules. In the same way, configuring your desktop is continuous with configuring a server is continuous with preparing a netboot image for an embedded device. If you know how to configure a NixOS desktop, you also know how to prepare your own custom NixOS install media. If you want it to, Nix can cure the stomach ache HCL gives you when you write Terraform.

Nixpkgs is also the largest collection of packages in existence.¹ Anything you could want to throw into an image is likely already there.

The author of the blog post is already a Nixpkgs/NixOS contributor, too, so they might also be thinking "some of the improvements I make in shrinking dependency closures or finding deeper ways to turn off certain features are potentially upstreamable".

And even if the experiment is a wash, in exploring this kind of (ab)use of NixOS for generating tiny images, a NixOS user is also learning more about the dependency relations and other structure of the NixOS systems they're already running, which might be interesting or rewarding.

I'm not saying that as a Nix enthusiast I'd never use Buildroot or Yocto, but I understand the appeal of exploring how far NixOS can be pushed for this and how easy or hard it is to do.

While we're here we should also note that NixOS isn't really the Nix tool for this job anyway. There's a cool project called not-os² where minimization is one of the goals that has already succeeded in getting the image size down to < 50 MB.

There's also a project targeting commodity wifi routers called Liminix, which likewise takes some NixOS ideas and uses them to produce teeny-tiny images, (presumably even smaller than not-os, given many of the target devices don't include so much as 50 MB of flash).

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1: https://repology.org/repositories/statistics/nonunique

2: https://github.com/cleverca22/not-os

3: https://www.liminix.org/