Building a NixOS Homelab

After one too many "what did I install on this box?" moments, I rebuilt my entire homelab on NixOS. Everything is declarative now — the whole machine is one git repo.

The flake

{
  description = "homelab";

  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";

  outputs = { self, nixpkgs }: {
    nixosConfigurations.box = nixpkgs.lib.nixosSystem {
      system = "x86_64-linux";
      modules = [ ./configuration.nix ];
    };
  };
}

Why it's worth it

• Reproducible — nixos-rebuild switch gets me an identical machine every time.
• Rollbacks — bad config? boot the previous generation.
• Documented by default — the config is the documentation.

# rebuild and switch
sudo nixos-rebuild switch --flake .#box

# roll back if it broke
sudo nixos-rebuild switch --rollback

NixOS is a rabbit hole. A very good rabbit hole.

It took a weekend to learn, but I haven't lost track of a single service since.