nixos/magnetico: init service

nixos/modules/module-list.nix

@@ -755,6 +755,7 @@
   ./services/system/uptimed.nix
   ./services/torrent/deluge.nix
   ./services/torrent/flexget.nix
+  ./services/torrent/magnetico.nix
   ./services/torrent/opentracker.nix
   ./services/torrent/peerflix.nix
   ./services/torrent/transmission.nix

nixos/modules/services/torrent/magnetico.nix

@@ -0,0 +1,214 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+  cfg = config.services.magnetico;
+
+  dataDir = "/var/lib/magnetico";
+
+  credFile = with cfg.web;
+    if credentialsFile != null
+      then credentialsFile
+      else pkgs.writeText "magnetico-credentials"
+        (concatStrings (mapAttrsToList
+          (user: hash: "${user}:${hash}\n")
+          cfg.web.credentials));
+
+  # default options in magneticod/main.go
+  dbURI = concatStrings
+    [ "sqlite3://${dataDir}/database.sqlite3"
+      "?_journal_mode=WAL"
+      "&_busy_timeout=3000"
+      "&_foreign_keys=true"
+    ];
+
+  crawlerArgs = with cfg.crawler; escapeShellArgs
+    ([ "--database=${dbURI}"
+       "--indexer-addr=${address}:${toString port}"
+       "--indexer-max-neighbors=${toString maxNeighbors}"
+       "--leech-max-n=${toString maxLeeches}"
+     ] ++ extraOptions);
+
+  webArgs = with cfg.web; escapeShellArgs
+    ([ "--database=${dbURI}"
+       (if (cfg.web.credentialsFile != null || cfg.web.credentials != { })
+         then "--credentials=${toString credFile}"
+         else "--no-auth")
+     ] ++ extraOptions);
+
+in {
+
+  ###### interface
+
+  options.services.magnetico = {
+    enable = mkEnableOption "Magnetico, Bittorrent DHT crawler";
+
+    crawler.address = mkOption {
+      type = types.str;
+      default = "0.0.0.0";
+      example = "1.2.3.4";
+      description = ''
+        Address to be used for indexing DHT nodes.
+      '';
+    };
+
+    crawler.port = mkOption {
+      type = types.port;
+      default = 0;
+      description = ''
+        Port to be used for indexing DHT nodes.
+        This port should be added to
+        <option>networking.firewall.allowedTCPPorts</option>.
+      '';
+    };
+
+    crawler.maxNeighbors = mkOption {
+      type = types.ints.positive;
+      default = 1000;
+      description = ''
+        Maximum number of simultaneous neighbors of an indexer.
+        Be careful changing this number: high values can very
+        easily cause your network to be congested or even crash
+        your router.
+      '';
+    };
+
+    crawler.maxLeeches = mkOption {
+      type = types.ints.positive;
+      default = 200;
+      description = ''
+        Maximum number of simultaneous leeches.
+      '';
+    };
+
+    crawler.extraOptions = mkOption {
+      type = types.listOf types.str;
+      default = [];
+      description = ''
+        Extra command line arguments to pass to magneticod.
+      '';
+    };
+
+    web.address = mkOption {
+      type = types.str;
+      default = "localhost";
+      example = "1.2.3.4";
+      description = ''
+        Address the web interface will listen to.
+      '';
+    };
+
+    web.port = mkOption {
+      type = types.port;
+      default = 8080;
+      description = ''
+        Port the web interface will listen to.
+      '';
+    };
+
+    web.credentials = mkOption {
+      type = types.attrsOf types.str;
+      default = {};
+      example = lib.literalExample ''
+        {
+          myuser = "$2y$12$YE01LZ8jrbQbx6c0s2hdZO71dSjn2p/O9XsYJpz.5968yCysUgiaG";
+        }
+      '';
+      description = ''
+        The credentials to access the web interface, in case authentication is
+        enabled, in the format <literal>username:hash</literal>. If unset no
+        authentication will be required.
+
+        Usernames must start with a lowercase ([a-z]) ASCII character, might
+        contain non-consecutive underscores except at the end, and consists of
+        small-case a-z characters and digits 0-9.  The
+        <command>htpasswd</command> tool from the <package>apacheHttpd
+        </package> package may be used to generate the hash: <command>htpasswd
+        -bnBC 12 username password</command>
+
+        <warning>
+        <para>
+          The hashes will be stored world-readable in the nix store.
+          Consider using the <literal>credentialsFile</literal> option if you
+          don't want this.
+        </para>
+        </warning>
+      '';
+    };
+
+    web.credentialsFile = mkOption {
+      type = types.nullOr types.path;
+      default = null;
+      description = ''
+        The path to the file holding the credentials to access the web
+        interface. If unset no authentication will be required.
+
+        The file must constain user names and password hashes in the format
+        <literal>username:hash </literal>, one for each line.  Usernames must
+        start with a lowecase ([a-z]) ASCII character, might contain
+        non-consecutive underscores except at the end, and consists of
+        small-case a-z characters and digits 0-9.
+        The <command>htpasswd</command> tool from the <package>apacheHttpd
+        </package> package may be used to generate the hash:
+        <command>htpasswd -bnBC 12 username password</command>
+      '';
+    };
+
+    web.extraOptions = mkOption {
+      type = types.listOf types.str;
+      default = [];
+      description = ''
+        Extra command line arguments to pass to magneticow.
+      '';
+    };
+
+  };
+
+  ###### implementation
+
+  config = mkIf cfg.enable {
+
+    users.users.magnetico = {
+      description = "Magnetico daemons user";
+    };
+
+    systemd.services.magneticod = {
+      description = "Magnetico DHT crawler";
+      wantedBy = [ "multi-user.target" ];
+      after    = [ "network-online.target" ];
+
+      serviceConfig = {
+        User      = "magnetico";
+        Restart   = "on-failure";
+        ExecStart = "${pkgs.magnetico}/bin/magneticod ${crawlerArgs}";
+      };
+    };
+
+    systemd.services.magneticow = {
+      description = "Magnetico web interface";
+      wantedBy = [ "multi-user.target" ];
+      after    = [ "network-online.target" "magneticod.service"];
+
+      serviceConfig = {
+        User           = "magnetico";
+        StateDirectory = "magnetico";
+        Restart        = "on-failure";
+        ExecStart      = "${pkgs.magnetico}/bin/magneticow ${webArgs}";
+      };
+    };
+
+    assertions =
+    [
+      {
+        assertion = cfg.web.credentialsFile != null || cfg.web.credentials != { };
+        message = ''
+          The options services.magnetico.web.credentialsFile and
+          services.magnetico.web.credentials are mutually exclusives.
+        '';
+      }
+    ];
+
+  };
+
+}