system/modules/nixos/configs/keyboard.nix

{ config, pkgs, lib, ... }:

let
  cfg = config.local.keyboard;
in
{
  options.local.keyboard = with lib; {
    enable = mkEnableOption "base keyboard configuration";
  };

  config = lib.mkIf cfg.enable {
    services.xserver.xkb = {
      model = "pc105";
      layout = "us,us";
      variant = "dvorak,";
      options = "grp:win_space_toggle";
    };

    console.useXkbConfig = true;
  };

}