depot/nixos/tests/mpd.nix

import ./make-test-python.nix (
  { pkgs, lib, ... }:
  let
    track = pkgs.fetchurl {
      # Sourced from http://freemusicarchive.org/music/Blue_Wave_Theory/Surf_Music_Month_Challenge/Skyhawk_Beach_fade_in

      name = "Blue_Wave_Theory-Skyhawk_Beach.mp3";
      url = "https://freemusicarchive.org/file/music/ccCommunity/Blue_Wave_Theory/Surf_Music_Month_Challenge/Blue_Wave_Theory_-_04_-_Skyhawk_Beach.mp3";
      hash = "sha256-91VDWwrcP6Cw4rk72VHvZ8RGfRBrpRE8xo/02dcJhHc=";
      meta.license = lib.licenses.cc-by-sa-40;
    };

    defaultCfg = rec {
      user = "mpd";
      group = "mpd";
      dataDir = "/var/lib/mpd";
      musicDirectory = "${dataDir}/music";
    };

    defaultMpdCfg = {
      inherit (defaultCfg)
        dataDir
        musicDirectory
        user
        group
        ;
      enable = true;
    };

    musicService =
      {
        user,
        group,
        musicDirectory,
      }:
      {
        description = "Sets up the music file(s) for MPD to use.";
        requires = [ "mpd.service" ];
        after = [ "mpd.service" ];
        wantedBy = [ "default.target" ];
        script = ''
          cp ${track} ${musicDirectory}
        '';
        serviceConfig = {
          User = user;
          Group = group;
        };
      };

    mkServer =
      { mpd, musicService }:
      {
        boot.kernelModules = [ "snd-dummy" ];
        services.mpd = mpd;
        systemd.services.musicService = musicService;
      };
  in
  {
    name = "mpd";
    meta = {
      maintainers = with lib.maintainers; [ emmanuelrosa ];
    };

    nodes = {
      client = { ... }: { };

      serverALSA =
        { ... }:
        lib.mkMerge [
          (mkServer {
            mpd = defaultMpdCfg // {
              network.listenAddress = "any";
              extraConfig = ''
                audio_output {
                  type "alsa"
                  name "ALSA"
                  mixer_type "null"
                }
              '';
            };
            musicService = musicService { inherit (defaultMpdCfg) user group musicDirectory; };
          })
          { networking.firewall.allowedTCPPorts = [ 6600 ]; }
        ];

      serverPulseAudio =
        { ... }:
        lib.mkMerge [
          (mkServer {
            mpd = defaultMpdCfg // {
              extraConfig = ''
                audio_output {
                  type "pulse"
                  name "The Pulse"
                }
              '';
            };

            musicService = musicService { inherit (defaultMpdCfg) user group musicDirectory; };
          })
          {
            hardware.pulseaudio = {
              enable = true;
              systemWide = true;
              tcp.enable = true;
              tcp.anonymousClients.allowAll = true;
            };
            systemd.services.mpd.environment.PULSE_SERVER = "localhost";
          }
        ];
    };

    testScript = ''
      mpc = "${lib.getExe pkgs.mpc} --wait"

      # Connects to the given server and attempts to play a tune.
      def play_some_music(server):
          server.wait_for_unit("mpd.service")
          server.succeed(f"{mpc} update")
          _, tracks = server.execute(f"{mpc} ls")

          for track in tracks.splitlines():
              server.succeed(f"{mpc} add {track}")

          _, added_tracks = server.execute(f"{mpc} playlist")

          # Check we succeeded adding audio tracks to the playlist
          assert len(added_tracks.splitlines()) > 0

          server.succeed(f"{mpc} play")

          _, output = server.execute(f"{mpc} status")
          # Assure audio track is playing
          assert "playing" in output

          server.succeed(f"{mpc} stop")


      play_some_music(serverALSA)
      play_some_music(serverPulseAudio)

      client.wait_for_unit("multi-user.target")
      client.succeed(f"{mpc} -h serverALSA status")

      # The PulseAudio-based server is configured not to accept external client connections
      # to perform the following test:
      client.fail(f"{mpc} -h serverPulseAudio status")
    '';
  }
)