nix-config/modules/dump-dvb/gnuradio.nix

{ pkgs, config, lib, ... }:
let
   receiver = pkgs.gnuradio-decoder;
   cfg = config.services.dump-dvb.gnuradio;
in
  {
    options.services.dump-dvb.gnuradio = {
      enable = lib.mkOption {
        type = lib.types.bool;
        default = false;
        description = ''Wether to enable dump-dvb gnuradio reciever'';
      };
      device = lib.mkOption {
        type = lib.types.str;
        default = "";
        example = "hackrf=0";
        description = ''Device string to pass to gnuradio'';
      };
      frequency = lib.mkOption {
        type = lib.types.int;
        default = 170795000;
        description = ''Frequency to tune radio to'';
      };
      offset = lib.mkOption {
        type = lib.types.int;
        default = 19550;
        description = ''Offset of the signal from center frequency'';
      };
    };

  config = lib.mkIf config.services.dump-dvb.gnuradio.enable {

    systemd.services."gnuradio" = {
      enable = true;
      wantedBy = [ "multi-user.target" ];

      script = "exec ${receiver}/bin/gnuradio-decoder-cpp ${toString cfg.frequency} ${toString cfg.offset} ${cfg.device} &";

      serviceConfig = {
        Type = "forking";
        User = "gnuradio";
        Restart = "on-failure";
        StartLimitBurst = "2";
        StartLimitIntervalSec = "150s";
      };
    };

  users.groups.gnuradio = {};
  users.users.gnuradio = {
    name = "gnuradio";
    description = "gnu radio service user";
    isSystemUser = true;
    group = "gnuradio";
    extraGroups = [ "plugdev" ];
  };

  security.wrappers.gnuradio-decode = {
    owner = "gnuradio";
    group = "users";
    capabilities = "cap_sys_nice+eip";
    source = "${receiver}/bin/gnuradio-decoder-cpp";
    };

  };
}