{lib, ...}: {
  options = with lib; {
    customOps = mkOption {
      description = "custom options";
      type = types.submodule {
        options = {
          owner = mkOption {
            type = types.str;
            default = null;
            description = "machine owner username";
          };
          domain = mkOption {
            type = types.str;
            default = null;
            description = "machine domain name";
          };
        };
      };
    };
  };
}