nixConfig/nixos/flake-module.nix

# copied and adopted from maralorns config

# This automatically searches for nixos configs in ./machines/${name}/configuration.nix
# and exposes them as outputs.nixosConfigurations.${name}
#

# a comment regarding  pkgs.nixos vs lib.nixosSystem
# while lib.nixosSystem is the usual enduser way to evaluate nixos configurations
# in flakes, pkgs.nixos sets the package set to the packages it comes from.
# This spares us tracking our potentiell overlays and own package additions, but just
# using the right package set to begin with. Using lib.nixosSystem from the flake we would
# need to specify that again.

{ withSystem, lib, inputs, ... }: {
  flake = {
    nixosConfigurations = withSystem "x86_64-linux" ({ pkgs, ... }:
    let
      machines = builtins.attrNames (builtins.readDir ./machines);
      makeSystem = name:
        pkgs.nixos {
          imports = [
            (import (./. + "/machines/${name}/configuration.nix") inputs)
            inputs.sops-nix.nixosModules.sops
            inputs.impermanence.nixosModules.impermanence
          ];
        };
    in lib.genAttrs machines makeSystem);
  };
}