{ config, pkgs, lib, ... }: let cfg = config.my.roles.ntp-server; in { options.my.roles.ntp-server.enable = lib.mkEnableOption "Enable NTP server"; config = lib.mkIf (cfg.enable) { services.chrony.extraConfig = '' allow 192.168.0.0/16 ''; networking.firewall.allowedUDPPorts = [ 123 ]; }; }