gmrender-resurrect: Add gmediarender service

This creates a systemd unit that will start and supervise the
gmediarender daemon.

nixos/doc/manual/from_md/release-notes/rl-2305.section.xml

@@ -68,6 +68,13 @@
           <link linkend="opt-programs.fzf.fuzzyCompletion">programs.fzf</link>.
         </para>
       </listitem>
+      <listitem>
+        <para>
+          <link xlink:href="https://github.com/hzeller/gmrender-resurrect">gmediarender</link>,
+          a simple, headless UPnP/DLNA renderer. Available as
+          <link xlink:href="options.html#opt-services.gmediarender.enable">services.gmediarender</link>.
+        </para>
+      </listitem>
       <listitem>
         <para>
           <link xlink:href="https://github.com/StevenBlack/hosts">stevenblack-blocklist</link>,

nixos/doc/manual/release-notes/rl-2305.section.md

@@ -26,6 +26,8 @@ In addition to numerous new and upgraded packages, this release has the followin
 
 - [fzf](https://github.com/junegunn/fzf), a command line fuzzyfinder. Available as [programs.fzf](#opt-programs.fzf.fuzzyCompletion).
 
+- [gmediarender](https://github.com/hzeller/gmrender-resurrect), a simple, headless UPnP/DLNA renderer.  Available as [services.gmediarender](options.html#opt-services.gmediarender.enable).
+
 - [stevenblack-blocklist](https://github.com/StevenBlack/hosts), A unified hosts file with base extensions for blocking unwanted websites. Available as [networking.stevenblack](options.html#opt-networking.stevenblack.enable).
 
 - [atuin](https://github.com/ellie/atuin), a sync server for shell history. Available as [services.atuin](#opt-services.atuin.enable).

nixos/modules/module-list.nix

@@ -295,6 +295,7 @@
   ./services/amqp/rabbitmq.nix
   ./services/audio/alsa.nix
   ./services/audio/botamusique.nix
+  ./services/audio/gmediarender.nix
   ./services/audio/hqplayerd.nix
   ./services/audio/icecast.nix
   ./services/audio/jack.nix

nixos/modules/services/audio/gmediarender.nix

@@ -0,0 +1,116 @@
+{ pkgs, lib, config, utils, ... }:
+
+with lib;
+
+let
+  cfg = config.services.gmediarender;
+in
+{
+  options.services.gmediarender = {
+    enable = mkEnableOption (mdDoc "the gmediarender DLNA renderer");
+
+    audioDevice = mkOption {
+      type = types.nullOr types.str;
+      default = null;
+      description = mdDoc ''
+        The audio device to use.
+      '';
+    };
+
+    audioSink = mkOption {
+      type = types.nullOr types.str;
+      default = null;
+      description = mdDoc ''
+        The audio sink to use.
+      '';
+    };
+
+    friendlyName = mkOption {
+      type = types.nullOr types.str;
+      default = null;
+      description = mdDoc ''
+        A "friendly name" for identifying the endpoint.
+      '';
+    };
+
+    initialVolume = mkOption {
+      type = types.nullOr types.int;
+      default = 0;
+      description = mdDoc ''
+        A default volume attenuation (in dB) for the endpoint.
+      '';
+    };
+
+    package = mkPackageOptionMD pkgs "gmediarender" {
+      default = "gmrender-resurrect";
+    };
+
+    port = mkOption {
+      type = types.nullOr types.port;
+      default = null;
+      description = mdDoc "Port that will be used to accept client connections.";
+    };
+
+    uuid = mkOption {
+      type = types.nullOr types.str;
+      default = null;
+      description = mdDoc ''
+        A UUID for uniquely identifying the endpoint.  If you have
+        multiple renderers on your network, you MUST set this.
+      '';
+    };
+  };
+
+  config = mkIf cfg.enable {
+    systemd = {
+      services.gmediarender = {
+        after = [ "network-online.target" ];
+        wantedBy = [ "multi-user.target" ];
+        description = "gmediarender server daemon";
+        environment = {
+          XDG_CACHE_HOME = "%t/gmediarender";
+        };
+        serviceConfig = {
+          DynamicUser = true;
+          User = "gmediarender";
+          Group = "gmediarender";
+          SupplementaryGroups = [ "audio" ];
+          ExecStart =
+            "${cfg.package}/bin/gmediarender " +
+            optionalString (cfg.audioDevice != null) ("--gstout-audiodevice=${utils.escapeSystemdExecArg cfg.audioDevice} ") +
+            optionalString (cfg.audioSink != null) ("--gstout-audiosink=${utils.escapeSystemdExecArg cfg.audioSink} ") +
+            optionalString (cfg.friendlyName != null) ("--friendly-name=${utils.escapeSystemdExecArg cfg.friendlyName} ") +
+            optionalString (cfg.initialVolume != 0) ("--initial-volume=${toString cfg.initialVolume} ") +
+            optionalString (cfg.port != null) ("--port=${toString cfg.port} ") +
+            optionalString (cfg.uuid != null) ("--uuid=${utils.escapeSystemdExecArg cfg.uuid} ");
+          Restart = "always";
+          RuntimeDirectory = "gmediarender";
+
+          # Security options:
+          CapabilityBoundingSet = "";
+          LockPersonality = true;
+          MemoryDenyWriteExecute = true;
+          NoNewPrivileges = true;
+          # PrivateDevices = true;
+          PrivateTmp = true;
+          PrivateUsers = true;
+          ProcSubset = "pid";
+          ProtectClock = true;
+          ProtectControlGroups = true;
+          ProtectHome = true;
+          ProtectHostname = true;
+          ProtectKernelLogs = true;
+          ProtectKernelModules = true;
+          ProtectKernelTunables = true;
+          ProtectProc = "invisible";
+          RestrictNamespaces = true;
+          RestrictRealtime = true;
+          RestrictSUIDSGID = true;
+          SystemCallArchitectures = "native";
+          SystemCallFilter = [ "@system-service" "~@privileged" ];
+          UMask = 066;
+        };
+      };
+    };
+  };
+}