nix-configuration/modules/system/system.nix

# System options
{
  pkgs,
  config,
  lib,
  ...
}:
let
  cfg = config.aux.system;
in
{
  options = {
    aux.system.packages = lib.mkOption {
      description = "Additional system packages to install. This is just a wrapper for environment.systemPackages.";
      type = lib.types.listOf lib.types.package;
      default = [ ];
      example = lib.literalExpression "[ pkgs.firefox pkgs.thunderbird ]";
    };
  };
  config = {
    # Set up the environment
    environment = {
      # Install base packages
      systemPackages =
        config.aux.system.packages
        ++ (with pkgs; [
          bash
          dconf # Needed to fix an issue with Home-manager. See https://github.com/nix-community/home-manager/issues/3113
          direnv
          git
          home-manager
          p7zip
        ]);
    };

    services = {
      # Enable fwupd (firmware updater)
      fwupd.enable = true;

      # Enable trim on supported drives
      fstrim.enable = true;

      # Autoscrub BTRFS partitions
      btrfs.autoScrub = lib.mkIf (config.fileSystems."/".fsType == "btrfs") {
        enable = true;
        interval = "weekly";
        fileSystems = [ "/" ];
      };

      # Allow systemd user services to keep running after the user has logged out
      logind.killUserProcesses = false;

      # Enable disk monitoring
      smartd = {
        enable = true;
        autodetect = true;
        notifications.wall.enable = true;
      };
    };

    # Limit logout stop timer duration to 30 seconds
    systemd.user.extraConfig = ''
      DefaultTimeoutStopSec=30s
    '';

    # Set your time zone.
    time.timeZone = "America/New_York";

    # Select internationalisation properties.
    i18n = {
      defaultLocale = "en_US.UTF-8";

      extraLocaleSettings = {
        LC_ADDRESS = "en_US.UTF-8";
        LC_IDENTIFICATION = "en_US.UTF-8";
        LC_MEASUREMENT = "en_US.UTF-8";
        LC_MONETARY = "en_US.UTF-8";
        LC_NAME = "en_US.UTF-8";
        LC_NUMERIC = "en_US.UTF-8";
        LC_PAPER = "en_US.UTF-8";
        LC_TELEPHONE = "en_US.UTF-8";
        LC_TIME = "en_US.UTF-8";
      };
    };
  };
}