{ mainConfig, feederConfig, pkgs, self, lib }: {

  config = {
    users.groups.${feederConfig.name} = { };
    users.users.${feederConfig.name} = {
      isSystemUser = true;
      group = "${feederConfig.name}";
    };

    systemd.services."${feederConfig.name}-mlat" =
      let
        uuidFile = pkgs.writeTextFile {
          name = "${feederConfig.name}-uuid";
          text = "${feederConfig.uuid}";
        };
        options = [
          "--input-type"
          feederConfig.mlat.input.type
          "--no-udp"
          "--input-connect"
          "${feederConfig.mlat.input.host}:${toString feederConfig.mlat.input.port}"
          "--server"
          feederConfig.mlat.server
          "--user"
          feederConfig.username
          "--lat"
          mainConfig.latitude
          "--lon"
          mainConfig.longitude
          "--alt"
          (toString mainConfig.altitude)
          "--uuid-file"
          "${uuidFile}"
        ] ++ (
          if feederConfig.mlat.privacy
          then
            [
              "--privacy"
            ]
          else
            [ ]
        ) ++ (
          map (result: "--result ${result}") feederConfig.mlat.results
        );
      in
      {
        enable = feederConfig.mlat.enable;
        description = "${feederConfig.name} MLAT client.";
        wants = [ "network.target" ];
        after = [ "network.target" ];
        unitConfig = {
          Documentation = "https://github.com/makrsmark/mlat-client/";
        };
        serviceConfig = {
          Type = "simple";
          User = "${feederConfig.name}";
          RuntimeDirectory = "${feederConfig.name}-mlat";
          RuntimeDirectoryMode = "0755";
          ExecStart = "${self.packages.${pkgs.system}.adsbfi-mlat-client}/bin/mlat-client ${lib.concatStringsSep " " options}";
          SyslogIdentifier = "${feederConfig.name}-mlat";
          Restart = "on-failure";
          RestartSec = 30;
          Nice = -1;
        };
        wantedBy = [ "multi-user.target" ];
      };

    systemd.services."${feederConfig.name}-feed" =
      let
        uuidFile = pkgs.writeTextFile {
          name = "${feederConfig.name}-uuid";
          text = "${feederConfig.uuid}";
        };
        connectors = map
          (
            connector: "--net-connector ${connector}"
          )
          (
            map
              (
                connector: (
                  lib.concatStringsSep "," (
                    [
                      connector.primary.host
                      (toString connector.primary.port)
                      connector.protocol
                    ] ++ (
                      if connector.silentFail
                      then
                        [
                          "silent_fail"
                        ]
                      else
                        [ ]
                    ) ++ (
                      if connector.secondary != null
                      then
                        [
                          connector.secondary.host
                          (toString connector.secondary.port)
                        ]
                      else
                        [ ]
                    )
                  )
                )
              )
              feederConfig.feed.connectors
          );
        options = [
          "--quiet"
          "--net"
          "--net-only"
          "--write-json"
          "%t/${feederConfig.name}-feed"
          "--net-beast-reduce-interval 0.5"
          "--net-heartbeat 60"
          "--net-ro-size 1280"
          "--net-ro-interval 0.2"
          "--net-ro-port 0"
          "--net-sbs-port 0"
          "--net-bi-port ${toString feederConfig.feed.beastInputPort}"
          "--net-bo-port 0"
          "--net-ri-port 0"
          "--write-json-every 1"
          "--lat"
          mainConfig.latitude
          "--lon"
          mainConfig.longitude
          "--max-range 450"
          "--json-location-accuracy 2"
          "--range-outline-hours 24"
          "--uuid-file"
          "${uuidFile}"
        ] ++ connectors;
      in
      {
        enable = feederConfig.feed.enable;
        description = "${feederConfig.name} feeder.";
        wants = [ "network.target" ];
        after = [ "network.target" ];
        unitConfig = {
          Documentation = "https://github.com/widehopf/readsb/";
          StartLimitIntervalSec = 1;
        };
        serviceConfig = {
          Type = "simple";
          User = "${feederConfig.name}";
          RuntimeDirectory = "${feederConfig.name}-feed";
          RuntimeDirectoryMode = "0755";
          ExecStart = "${self.packages.${pkgs.system}.adsbfi-readsb}/bin/readsb ${lib.concatStringsSep " " options}";
          SyslogIdentifier = "${feederConfig.name}-feed";
          Restart = "on-failure";
          RestartSec = 30;
          StartLimitBurst = 100;
          Nice = -1;
        };
        wantedBy = [ "multi-user.target" ];
      };
  };
}