nixos/syncplay: add missing options

Exposes all currently available command-line arguments that were
missing, including some that were impossible to use with the catch-all
option `extraArgs` alone, requiring changes to other parts of the
system.
Those are now all self-contained in the module.
The service now uses systemd's `DynamicUsers`.

nixos/doc/manual/release-notes/rl-2411.section.md

@@ -368,6 +368,9 @@
 - The `antennas` package and the `services.antennas` module have been
   removed as they only work with `tvheadend` (see above).
 
+- The `services.syncplay` module now exposes all currently available command-line arguments for `syncplay-server` as options, as well as a `useACMEHost` option for easy TLS setup.
+  The systemd service now uses `DynamicUser`/`StateDirectory` and the `user` and `group` options have been deprecated.
+
 ## Other Notable Changes {#sec-release-24.11-notable-changes}
 
 <!-- To avoid merge conflicts, consider adding your item at an arbitrary place in the list instead. -->

nixos/modules/services/networking/syncplay.nix

@@ -7,18 +7,41 @@ let
 
   cmdArgs =
     [ "--port" cfg.port ]
+    ++ optionals (cfg.isolateRooms) [ "--isolate-rooms" ]
+    ++ optionals (!cfg.ready) [ "--disable-ready" ]
+    ++ optionals (!cfg.chat) [ "--disable-chat" ]
     ++ optionals (cfg.salt != null) [ "--salt" cfg.salt ]
+    ++ optionals (cfg.motdFile != null) [ "--motd-file" cfg.motdFile ]
+    ++ optionals (cfg.roomsDBFile != null) [ "--rooms-db-file" cfg.roomsDBFile ]
+    ++ optionals (cfg.permanentRoomsFile != null) [ "--permanent-rooms-file" cfg.permanentRoomsFile ]
+    ++ [ "--max-chat-message-length" cfg.maxChatMessageLength ]
+    ++ [ "--max-username-length" cfg.maxUsernameLength ]
+    ++ optionals (cfg.statsDBFile != null) [ "--stats-db-file" cfg.statsDBFile ]
     ++ optionals (cfg.certDir != null) [ "--tls" cfg.certDir ]
+    ++ optionals cfg.ipv4Only [ "--ipv4-only" ]
+    ++ optionals cfg.ipv6Only [ "--ipv6-only" ]
+    ++ optionals (cfg.interfaceIpv4 != "") [ "--interface-ipv4" cfg.interfaceIpv4 ]
+    ++ optionals (cfg.interfaceIpv6 != "") [ "--interface-ipv6" cfg.interfaceIpv6 ]
     ++ cfg.extraArgs;
 
+  useACMEHostDir = optionalString (cfg.useACMEHost != null) config.security.acme.certs.${cfg.useACMEHost}.directory;
 in
 {
+  imports = [
+    (mkRemovedOptionModule [ "services" "syncplay" "user" ]
+      "The syncplay service now uses DynamicUser, override the systemd unit settings if you need the old functionality.")
+    (mkRemovedOptionModule [ "services" "syncplay" "group" ]
+      "The syncplay service now uses DynamicUser, override the systemd unit settings if you need the old functionality.")
+  ];
+
   options = {
     services.syncplay = {
       enable = mkOption {
         type = types.bool;
         default = false;
-        description = "If enabled, start the Syncplay server.";
+        description = ''
+          If enabled, start the Syncplay server.
+        '';
       };
 
       port = mkOption {
@@ -29,6 +52,39 @@ in
         '';
       };
 
+      passwordFile = mkOption {
+        type = types.nullOr types.path;
+        default = null;
+        description = ''
+          Path to the file that contains the server password. If
+          `null`, the server doesn't require a password.
+        '';
+      };
+
+      isolateRooms = mkOption {
+        type = types.bool;
+        default = false;
+        description = ''
+          Enable room isolation.
+        '';
+      };
+
+      ready = mkOption {
+        type = types.bool;
+        default = true;
+        description = ''
+          Check readiness of users.
+        '';
+      };
+
+      chat = mkOption {
+        type = types.bool;
+        default = true;
+        description = ''
+          Chat with users in the same room.
+        '';
+      };
+
       salt = mkOption {
         type = types.nullOr types.str;
         default = null;
@@ -37,7 +93,7 @@ in
           instance to still work when the server is restarted.  The salt will be
           readable in the nix store and the processlist.  If this is not
           intended use `saltFile` instead.  Mutually exclusive with
-          <option>services.syncplay.saltFile</option>.
+          {option}`services.syncplay.saltFile`.
         '';
       };
 
@@ -49,7 +105,83 @@ in
           operator passwords generated by this server instance to still work
           when the server is restarted.  `null`, the server doesn't load the
           salt from a file.  Mutually exclusive with
-          <option>services.syncplay.salt</option>.
+          {option}`services.syncplay.salt`.
+        '';
+      };
+
+      motd = mkOption {
+        type = types.nullOr types.str;
+        default = null;
+        description = ''
+          Text to display when users join. The motd will be readable in the nix store
+          and the processlist.  If this is not intended use `motdFile` instead.
+          Will be overriden by {option}`services.syncplay.motdFile`.
+        '';
+      };
+
+      motdFile = mkOption {
+        type = types.nullOr types.str;
+        default = if cfg.motd != null then (builtins.toFile "motd" cfg.motd) else null;
+        defaultText = literalExpression ''if services.syncplay.motd != null then (builtins.toFile "motd" services.syncplay.motd) else null'';
+        description = ''
+          Path to text to display when users join.
+          Will override {option}`services.syncplay.motd`.
+        '';
+      };
+
+      roomsDBFile = mkOption {
+        type = types.nullOr types.str;
+        default = null;
+        example = "rooms.db";
+        description = ''
+          Path to SQLite database file to store room states.
+          Relative to the working directory provided by systemd.
+        '';
+      };
+
+      permanentRooms = mkOption {
+        type = types.listOf types.str;
+        default = [ ];
+        description = ''
+          List of rooms that will be listed even if the room is empty.
+          Will be overriden by {option}`services.syncplay.permanentRoomsFile`.
+        '';
+      };
+
+      permanentRoomsFile = mkOption {
+        type = types.nullOr types.str;
+        default = if cfg.permanentRooms != [ ] then (builtins.toFile "perm" (builtins.concatStringsSep "\n" cfg.permanentRooms)) else null;
+        defaultText = literalExpression ''if services.syncplay.permanentRooms != [ ] then (builtins.toFile "perm" (builtins.concatStringsSep "\n" services.syncplay.permanentRooms)) else null'';
+        description = ''
+          File with list of rooms that will be listed even if the room is empty,
+          newline delimited.
+          Will override {option}`services.syncplay.permanentRooms`.
+        '';
+      };
+
+      maxChatMessageLength = mkOption {
+        type = types.ints.unsigned;
+        default = 150;
+        description = ''
+          Maximum number of characters in a chat message.
+        '';
+      };
+
+      maxUsernameLength = mkOption {
+        type = types.ints.unsigned;
+        default = 16;
+        description = ''
+          Maximum number of characters in a username.
+        '';
+      };
+
+      statsDBFile = mkOption {
+        type = types.nullOr types.str;
+        default = null;
+        example = "stats.db";
+        description = ''
+          Path to SQLite database file to store stats.
+          Relative to the working directory provided by systemd.
         '';
       };
 
@@ -62,6 +194,49 @@ in
         '';
       };
 
+      useACMEHost = mkOption {
+        type = types.nullOr types.str;
+        default = null;
+        example = "syncplay.example.com";
+        description = ''
+          If set, use NixOS-generated ACME certificate with the specified name for TLS.
+
+          Note that it requires {option}`security.acme` to be setup, e.g., credentials provided if using DNS-01 validation.
+        '';
+      };
+
+      ipv4Only = mkOption {
+        type = types.bool;
+        default = false;
+        description = ''
+          Listen only on IPv4 when strting the server.
+        '';
+      };
+
+      ipv6Only = mkOption {
+        type = types.bool;
+        default = false;
+        description = ''
+          Listen only on IPv6 when strting the server.
+        '';
+      };
+
+      interfaceIpv4 = mkOption {
+        type = types.str;
+        default = "";
+        description = ''
+          The IP address to bind to for IPv4. Leaving it empty defaults to using all.
+        '';
+      };
+
+      interfaceIpv6 = mkOption {
+        type = types.str;
+        default = "";
+        description = ''
+          The IP address to bind to for IPv6. Leaving it empty defaults to using all.
+        '';
+      };
+
       extraArgs = mkOption {
         type = types.listOf types.str;
         default = [ ];
@@ -70,28 +245,12 @@ in
         '';
       };
 
-      user = mkOption {
+      package = mkOption {
-        type = types.str;
+        type = types.package;
-        default = "nobody";
+        default = pkgs.syncplay-nogui;
+        defaultText = literalExpression "pkgs.syncplay-nogui";
         description = ''
-          User to use when running Syncplay.
+          Package to use for syncplay.
-        '';
-      };
-
-      group = mkOption {
-        type = types.str;
-        default = "nogroup";
-        description = ''
-          Group to use when running Syncplay.
-        '';
-      };
-
-      passwordFile = mkOption {
-        type = types.nullOr types.path;
-        default = null;
-        description = ''
-          Path to the file that contains the server password. If
-          `null`, the server doesn't require a password.
         '';
       };
     };
@@ -103,7 +262,24 @@ in
         assertion = cfg.salt == null || cfg.saltFile == null;
         message = "services.syncplay.salt and services.syncplay.saltFile are mutually exclusive.";
       }
+      {
+        assertion = cfg.certDir == null || cfg.useACMEHost == null;
+        message = "services.syncplay.certDir and services.syncplay.useACMEHost are mutually exclusive.";
+      }
+      {
+        assertion = !cfg.ipv4Only || !cfg.ipv6Only;
+        message = "services.syncplay.ipv4Only and services.syncplay.ipv6Only are mutually exclusive.";
+      }
     ];
+
+    warnings = optional (cfg.interfaceIpv4 != "" && cfg.ipv6Only) "You have specified services.syncplay.interfaceIpv4 but IPv4 is disabled by services.syncplay.ipv6Only."
+      ++ optional (cfg.interfaceIpv6 != "" && cfg.ipv4Only) "You have specified services.syncplay.interfaceIpv6 but IPv6 is disabled by services.syncplay.ipv4Only.";
+
+    security.acme.certs = mkIf (cfg.useACMEHost != null) {
+      "${cfg.useACMEHost}".reloadServices = [ "syncplay.service" ];
+    };
+
+    networking.firewall.allowedTCPPorts = [ cfg.port ];
     systemd.services.syncplay = {
       description = "Syncplay Service";
       wantedBy = [ "multi-user.target" ];
@@ -111,20 +287,26 @@ in
       after = [ "network-online.target" ];
 
       serviceConfig = {
-        User = cfg.user;
+        DynamicUser = true;
-        Group = cfg.group;
+        StateDirectory = "syncplay";
-        LoadCredential = lib.optional (cfg.passwordFile != null) "password:${cfg.passwordFile}"
+        WorkingDirectory = "%S/syncplay";
-          ++ lib.optional (cfg.saltFile != null) "salt:${cfg.saltFile}";
+        LoadCredential = optional (cfg.passwordFile != null) "password:${cfg.passwordFile}"
+          ++ optional (cfg.saltFile != null) "salt:${cfg.saltFile}"
+          ++ optionals (cfg.useACMEHost != null) [
+          "cert.pem:${useACMEHostDir}/cert.pem"
+          "privkey.pem:${useACMEHostDir}/key.pem"
+          "chain.pem:${useACMEHostDir}/chain.pem"
+        ];
       };
 
       script = ''
-        ${lib.optionalString (cfg.passwordFile != null) ''
+        ${optionalString (cfg.passwordFile != null) ''
           export SYNCPLAY_PASSWORD=$(cat "''${CREDENTIALS_DIRECTORY}/password")
         ''}
-        ${lib.optionalString (cfg.saltFile != null) ''
+        ${optionalString (cfg.saltFile != null) ''
           export SYNCPLAY_SALT=$(cat "''${CREDENTIALS_DIRECTORY}/salt")
         ''}
-        exec ${pkgs.syncplay-nogui}/bin/syncplay-server ${escapeShellArgs cmdArgs}
+        exec ${cfg.package}/bin/syncplay-server ${escapeShellArgs cmdArgs} ${optionalString (cfg.useACMEHost != null) "--tls $CREDENTIALS_DIRECTORY"}
       '';
     };
   };