nixos/rtorrent: add service

nixos/modules/module-list.nix

@@ -809,6 +809,7 @@
   ./services/torrent/magnetico.nix
   ./services/torrent/opentracker.nix
   ./services/torrent/peerflix.nix
+  ./services/torrent/rtorrent.nix
   ./services/torrent/transmission.nix
   ./services/ttys/agetty.nix
   ./services/ttys/gpm.nix

nixos/modules/services/torrent/rtorrent.nix

@@ -0,0 +1,209 @@
+{ config, pkgs, lib, ... }:
+
+with lib;
+
+let
+
+  cfg = config.services.rtorrent;
+
+in {
+  options.services.rtorrent = {
+    enable = mkEnableOption "rtorrent";
+
+    dataDir = mkOption {
+      type = types.str;
+      default = "/var/lib/rtorrent";
+      description = ''
+        The directory where rtorrent stores its data files.
+      '';
+    };
+
+    downloadDir = mkOption {
+      type = types.str;
+      default = "${cfg.dataDir}/download";
+      description = ''
+        Where to put downloaded files.
+      '';
+    };
+
+    user = mkOption {
+      type = types.str;
+      default = "rtorrent";
+      description = ''
+        User account under which rtorrent runs.
+      '';
+    };
+
+    group = mkOption {
+      type = types.str;
+      default = "rtorrent";
+      description = ''
+        Group under which rtorrent runs.
+      '';
+    };
+
+    package = mkOption {
+      type = types.package;
+      default = pkgs.rtorrent;
+      defaultText = "pkgs.rtorrent";
+      description = ''
+        The rtorrent package to use.
+      '';
+    };
+
+    port = mkOption {
+      type = types.port;
+      default = 50000;
+      description = ''
+        The rtorrent port.
+      '';
+    };
+
+    openFirewall = mkOption {
+      type = types.bool;
+      default = false;
+      description = ''
+        Whether to open the firewall for the port in <option>services.rtorrent.port</option>.
+      '';
+    };
+
+    rpcSocket = mkOption {
+      type = types.str;
+      readOnly = true;
+      default = "/run/rtorrent/rpc.sock";
+      description = ''
+        RPC socket path.
+      '';
+    };
+
+    configText = mkOption {
+      type = types.lines;
+      default = "";
+      description = ''
+        The content of <filename>rtorrent.rc</filename>. The <link xlink:href="https://rtorrent-docs.readthedocs.io/en/latest/cookbook.html#modernized-configuration-template">modernized configuration template</link> with the values specified in this module will be prepended using mkBefore. You can use mkForce to overwrite the config completly.
+      '';
+    };
+  };
+
+  config = mkIf cfg.enable {
+
+    users.groups = mkIf (cfg.group == "rtorrent") {
+      rtorrent = {};
+    };
+
+    users.users = mkIf (cfg.user == "rtorrent") {
+      rtorrent = {
+        group = cfg.group;
+        shell = pkgs.bashInteractive;
+        home = cfg.dataDir;
+        description = "rtorrent Daemon user";
+        isSystemUser = true;
+      };
+    };
+
+    networking.firewall.allowedTCPPorts = mkIf (cfg.openFirewall) [ cfg.port ];
+
+    services.rtorrent.configText = mkBefore ''
+      # Instance layout (base paths)
+      method.insert = cfg.basedir, private|const|string, (cat,"${cfg.dataDir}/")
+      method.insert = cfg.watch,   private|const|string, (cat,(cfg.basedir),"watch/")
+      method.insert = cfg.logs,    private|const|string, (cat,(cfg.basedir),"log/")
+      method.insert = cfg.logfile, private|const|string, (cat,(cfg.logs),(system.time),".log")
+      method.insert = cfg.rpcsock, private|const|string, (cat,"${cfg.rpcSocket}")
+
+      # Create instance directories
+      execute.throw = sh, -c, (cat, "mkdir -p ", (cfg.basedir), "/session ", (cfg.watch), " ", (cfg.logs))
+
+      # Listening port for incoming peer traffic (fixed; you can also randomize it)
+      network.port_range.set = ${toString cfg.port}-${toString cfg.port}
+      network.port_random.set = no
+
+      # Tracker-less torrent and UDP tracker support
+      # (conservative settings for 'private' trackers, change for 'public')
+      dht.mode.set = disable
+      protocol.pex.set = no
+      trackers.use_udp.set = no
+
+      # Peer settings
+      throttle.max_uploads.set = 100
+      throttle.max_uploads.global.set = 250
+
+      throttle.min_peers.normal.set = 20
+      throttle.max_peers.normal.set = 60
+      throttle.min_peers.seed.set = 30
+      throttle.max_peers.seed.set = 80
+      trackers.numwant.set = 80
+
+      protocol.encryption.set = allow_incoming,try_outgoing,enable_retry
+
+      # Limits for file handle resources, this is optimized for
+      # an `ulimit` of 1024 (a common default). You MUST leave
+      # a ceiling of handles reserved for rTorrent's internal needs!
+      network.http.max_open.set = 50
+      network.max_open_files.set = 600
+      network.max_open_sockets.set = 3000
+
+      # Memory resource usage (increase if you have a large number of items loaded,
+      # and/or the available resources to spend)
+      pieces.memory.max.set = 1800M
+      network.xmlrpc.size_limit.set = 4M
+
+      # Basic operational settings (no need to change these)
+      session.path.set = (cat, (cfg.basedir), "session/")
+      directory.default.set = "${cfg.downloadDir}"
+      log.execute = (cat, (cfg.logs), "execute.log")
+      ##log.xmlrpc = (cat, (cfg.logs), "xmlrpc.log")
+      execute.nothrow = sh, -c, (cat, "echo >", (session.path), "rtorrent.pid", " ", (system.pid))
+
+      # Other operational settings (check & adapt)
+      encoding.add = utf8
+      system.umask.set = 0027
+      system.cwd.set = (cfg.basedir)
+      network.http.dns_cache_timeout.set = 25
+      schedule2 = monitor_diskspace, 15, 60, ((close_low_diskspace, 1000M))
+
+      # Watch directories (add more as you like, but use unique schedule names)
+      #schedule2 = watch_start, 10, 10, ((load.start, (cat, (cfg.watch), "start/*.torrent")))
+      #schedule2 = watch_load, 11, 10, ((load.normal, (cat, (cfg.watch), "load/*.torrent")))
+
+      # Logging:
+      #   Levels = critical error warn notice info debug
+      #   Groups = connection_* dht_* peer_* rpc_* storage_* thread_* tracker_* torrent_*
+      print = (cat, "Logging to ", (cfg.logfile))
+      log.open_file = "log", (cfg.logfile)
+      log.add_output = "info", "log"
+      ##log.add_output = "tracker_debug", "log"
+
+      # XMLRPC
+      scgi_local = (cfg.rpcsock)
+      schedule = scgi_group,0,0,"execute.nothrow=chown,\":rtorrent\",(cfg.rpcsock)"
+      schedule = scgi_permission,0,0,"execute.nothrow=chmod,\"g+w,o=\",(cfg.rpcsock)"
+    '';
+
+    systemd = {
+      services = {
+        rtorrent = let
+          rtorrentConfigFile = pkgs.writeText "rtorrent.rc" cfg.configText;
+        in {
+          description = "rTorrent system service";
+          after = [ "network.target" ];
+          path = [ cfg.package pkgs.bash ];
+          wantedBy = [ "multi-user.target" ];
+          serviceConfig = {
+            User = cfg.user;
+            Group = cfg.group;
+            Type = "simple";
+            Restart = "on-failure";
+            WorkingDirectory = cfg.dataDir;
+            ExecStartPre=''${pkgs.bash}/bin/bash -c "if test -e ${cfg.dataDir}/session/rtorrent.lock && test -z $(${pkgs.procps}/bin/pidof rtorrent); then rm -f ${cfg.dataDir}/session/rtorrent.lock; fi"'';
+            ExecStart="${cfg.package}/bin/rtorrent -n -o system.daemon.set=true -o import=${rtorrentConfigFile}";
+            RuntimeDirectory = "rtorrent";
+            RuntimeDirectoryMode = 755;
+          };
+        };
+      };
+
+      tmpfiles.rules = [ "d '${cfg.dataDir}' 0750 ${cfg.user} ${cfg.group} -" ];
+    };
+  };
+}