nixos/tedicross: add module

nixos/modules/module-list.nix

@@ -672,6 +672,7 @@
   ./services/networking/syncthing-relay.nix
   ./services/networking/tcpcrypt.nix
   ./services/networking/teamspeak3.nix
+  ./services/networking/tedicross.nix
   ./services/networking/tinc.nix
   ./services/networking/tinydns.nix
   ./services/networking/tftpd.nix

nixos/modules/services/networking/tedicross.nix

@@ -0,0 +1,100 @@
+{ config, pkgs, lib, ... }:
+
+with lib;
+
+let
+  dataDir = "/var/lib/tedicross";
+  cfg = config.services.tedicross;
+  configJSON = pkgs.writeText "tedicross-settings.json" (builtins.toJSON cfg.config);
+  configYAML = pkgs.runCommand "tedicross-settings.yaml" { preferLocalBuild = true; } ''
+    ${pkgs.remarshal}/bin/json2yaml -i ${configJSON} -o $out
+  '';
+
+in {
+  options = {
+    services.tedicross = {
+      enable = mkEnableOption "the TediCross Telegram-Discord bridge service";
+
+      config = mkOption {
+        type = types.attrs;
+        # from https://github.com/TediCross/TediCross/blob/master/example.settings.yaml
+        example = literalExample ''
+          {
+            telegram = {
+              useFirstNameInsteadOfUsername = false;
+              colonAfterSenderName = false;
+              skipOldMessages = true;
+              sendEmojiWithStickers = true;
+            };
+            discord = {
+              useNickname = false;
+              skipOldMessages = true;
+              displayTelegramReplies = "embed";
+              replyLength = 100;
+            };
+            bridges = [
+              {
+                name = "Default bridge";
+                direction = "both";
+                telegram = {
+                  chatId = -123456789;
+                  relayJoinMessages = true;
+                  relayLeaveMessages = true;
+                  sendUsernames = true;
+                  ignoreCommands = true;
+                };
+                discord = {
+                  serverId = "DISCORD_SERVER_ID";
+                  channelId = "DISCORD_CHANNEL_ID";
+                  relayJoinMessages = true;
+                  relayLeaveMessages = true;
+                  sendUsernames = true;
+                  crossDeleteOnTelegram = true;
+                };
+              }
+            ];
+
+            debug = false;
+          }
+        '';
+        description = ''
+          <filename>settings.yaml</filename> configuration as a Nix attribute set.
+          Secret tokens should be specified using <option>environmentFile</option>
+          instead of this world-readable file.
+        '';
+      };
+
+      environmentFile = mkOption {
+        type = types.nullOr types.path;
+        default = null;
+        description = ''
+          File containing environment variables to be passed to the TediCross service,
+          in which secret tokens can be specified securely using the
+          <literal>TELEGRAM_BOT_TOKEN</literal> and <literal>DISCORD_BOT_TOKEN</literal>
+          keys.
+        '';
+      };
+    };
+  };
+
+  config = mkIf cfg.enable {
+    # from https://github.com/TediCross/TediCross/blob/master/guides/autostart/Linux.md
+    systemd.services.tedicross = {
+      description = "TediCross Telegram-Discord bridge service";
+      wantedBy = [ "multi-user.target" ];
+      wants = [ "network-online.target" ];
+      after = [ "network-online.target" ];
+      serviceConfig = {
+        Type = "simple";
+        ExecStart = "${pkgs.nodePackages.tedicross}/bin/tedicross --config='${configYAML}' --data-dir='${dataDir}'";
+        Restart = "always";
+        DynamicUser = true;
+        StateDirectory = baseNameOf dataDir;
+        EnvironmentFile = cfg.environmentFile;
+      };
+    };
+  };
+
+  meta.maintainers = with maintainers; [ pacien ];
+}
+