1 files changed, 199 insertions, 0 deletions

diff --git a/custom/mpd.nix b/custom/mpd.nix
new file mode 100644
index 00000000..8df2a955
--- /dev/null
+++ b/custom/mpd.nix
@@ -0,0 +1,199 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+
+  name = "mpd";
+
+  uid = config.ids.uids.mpd;
+  gid = config.ids.gids.mpd;
+  cfg = config.services.mpd;
+
+  mpdConf = pkgs.writeText "mpd.conf" ''
+    music_directory     "${cfg.musicDirectory}"
+    playlist_directory  "${cfg.playlistDirectory}"
+    db_file             "${cfg.dbFile}"
+    state_file          "${cfg.dataDir}/state"
+    sticker_file        "${cfg.dataDir}/sticker.sql"
+    log_file            "syslog"
+    user                "${cfg.user}"
+    group               "${cfg.group}"
+
+    ${optionalString (cfg.network.listenAddress != "any") ''bind_to_address "${cfg.network.listenAddress}"''}
+    ${optionalString (cfg.network.port != 6600)  ''port "${toString cfg.network.port}"''}
+
+    ${cfg.extraConfig}
+  '';
+
+  tcpAddress = {
+    options = {
+      address = mkOption {
+        type = with types; either (enum ["any"]) str;
+        example = "localhost";
+      };
+
+      port = mkOption {
+        type = types.int;
+        default = 6600;
+      };
+    };
+  };
+
+  listenStream = arg: if isString arg then arg else (optionalString (arg.address != "any") (arg.address + ":")) + toString arg.port;
+  bindAddress = arg: if isString arg then arg
+                else arg.address + ":" + toString arg.port;
+
+in {
+
+  disabledModules = [ "services/audio/mpd.nix" ];
+
+  ###### interface
+
+  options = {
+
+    services.mpd = {
+
+      enable = mkOption {
+        type = types.bool;
+        default = false;
+        description = ''
+          Whether to enable MPD, the music player daemon.
+        '';
+      };
+
+      startWhenNeeded = mkOption {
+        type = types.bool;
+        default = false;
+        description = ''
+          If set, <command>mpd</command> is socket-activated; that
+          is, instead of having it permanently running as a daemon,
+          systemd will start it on the first incoming connection.
+        '';
+      };
+
+      musicDirectory = mkOption {
+        type = with types; either path str;
+        default = "${cfg.dataDir}/music";
+        defaultText = ''''${dataDir}/music'';
+        description = ''
+          The directory where mpd reads music from.
+        '';
+      };
+
+      playlistDirectory = mkOption {
+        type = types.path;
+        default = "${cfg.dataDir}/playlists";
+        defaultText = ''''${dataDir}/playlists'';
+        description = ''
+          The directory where mpd stores playlists.
+        '';
+      };
+
+      extraConfig = mkOption {
+        type = types.lines;
+        default = "";
+        description = ''
+          Extra directives added to to the end of MPD's configuration file,
+          mpd.conf. Basic configuration like file location and uid/gid
+          is added automatically to the beginning of the file. For available
+          options see <literal>man 5 mpd.conf</literal>'.
+        '';
+      };
+
+      dataDir = mkOption {
+        type = types.path;
+        default = "/var/lib/${name}";
+        description = ''
+          The directory where MPD stores its state, tag cache,
+          playlists etc.
+        '';
+      };
+
+      user = mkOption {
+        type = types.str;
+        default = name;
+        description = "User account under which MPD runs.";
+      };
+
+      group = mkOption {
+        type = types.str;
+        default = name;
+        description = "Group account under which MPD runs.";
+      };
+
+      listenAddresses = mkOption {
+        type = with types; listOf (either (submodule tcpAddress) str);
+        default = [{ address = "127.0.0.1"; }];
+      };
+
+      dbFile = mkOption {
+        type = types.str;
+        default = "${cfg.dataDir}/tag_cache";
+        defaultText = ''''${dataDir}/tag_cache'';
+        description = ''
+          The path to MPD's database.
+        '';
+      };
+    };
+
+  };
+
+
+  ###### implementation
+
+  config = mkIf cfg.enable {
+
+    systemd.sockets.mpd = mkIf cfg.startWhenNeeded {
+      description = "Music Player Daemon Socket";
+      wantedBy = [ "sockets.target" ];
+      listenStreams = map listenStream cfg.listenAddresses;
+      socketConfig = {
+        Backlog = 5;
+        KeepAlive = true;
+        PassCredentials = true;
+      };
+    };
+
+    systemd.services.mpd = {
+      after = [ "network.target" "sound.target" ];
+      description = "Music Player Daemon";
+      wantedBy = optional (!cfg.startWhenNeeded) "multi-user.target";
+
+      preStart = ''
+        mkdir -p "${cfg.dataDir}" && chown -R ${cfg.user}:${cfg.group} "${cfg.dataDir}"
+        mkdir -p "${cfg.playlistDirectory}" && chown -R ${cfg.user}:${cfg.group} "${cfg.playlistDirectory}"
+      '';
+      serviceConfig = {
+        User = "${cfg.user}";
+        PermissionsStartOnly = true;
+        ExecStart = "${pkgs.mpd}/bin/mpd --no-daemon ${mpdConf}";
+        Type = "notify";
+        LimitRTPRIO = 50;
+        LimitRTTIME = "infinity";
+        ProtectSystem = true;
+        NoNewPrivileges = true;
+        ProtectKernelTunables = true;
+        ProtectControlGroups = true;
+        ProtectKernelModules = true;
+        RestrictAddressFamilies = "AF_INET AF_INET6 AF_UNIX AF_NETLINK";
+        RestrictNamespaces = true;
+      };
+    };
+
+    users.extraUsers = optionalAttrs (cfg.user == name) (singleton {
+      inherit uid;
+      inherit name;
+      group = cfg.group;
+      extraGroups = [ "audio" ];
+      description = "Music Player Daemon user";
+      home = "${cfg.dataDir}";
+    });
+
+    users.extraGroups = optionalAttrs (cfg.group == name) (singleton {
+      inherit name;
+      gid = gid;
+    });
+  };
+
+}