nixos/modules/nixos/greetd.nix

{
  config,
  lib,
  pkgs,
  ...
}: let
  swayConfig = pkgs.writeText "greetd-sway-config" ''
    input * {
      xkb_layout "de"
      xkb_options "caps:ctrl_modifier"
      xkb_numlock "enable"
    }
    input "type:touchpad" {
      tap "enable"
      natural_scroll "enable"
    }

    exec dbus-sway-environment
    exec configure-gtk
    # `-l` activates layer-shell mode. Notice that `swaymsg exit` will run after gtkgreet.
    exec "${pkgs.greetd.regreet}/bin/regreet; swaymsg exit"
    bindsym Mod4+shift+e exec swaynag \
        -t warning \
        -m 'What do you want to do?' \
        -b 'Poweroff' 'systemctl poweroff' \
        -b 'Reboot' 'systemctl reboot'
  '';
in {
  programs.regreet.enable = true;

  users.users.greeter = {
    isNormalUser = false;
    description = "Greeter";
    extraGroups = [];
  };

  services.greetd = {
    enable = true;
    settings = {
      initial_session = {
        command = "${pkgs.sway}/bin/sway --config ${swayConfig}";
        user = "greeter";
      };
    };
  };

  environment.etc."greetd/environments".text = ''
    sway
  '';
}