WIP: matrix: add signal bridge

hosts/servo/services/matrix/default.nix

@@ -6,8 +6,16 @@
   imports = [
     ./discord-puppet.nix
     # ./irc.nix
+    ./signal.nix
   ];
 
+  services.matrix-appservices = {
+    # configure defaults. used by e.g. ./signal.nix
+    homeserverUrl = "http://127.0.0.1:8008";
+    homeserverDomain = "uninsane.org";
+    addRegistrationFiles = true;
+  };
+
   sane.persist.sys.plaintext = [
     { user = "matrix-synapse"; group = "matrix-synapse"; directory = "/var/lib/matrix-synapse"; }
   ];

hosts/servo/services/matrix/signal.nix

@@ -0,0 +1,32 @@
+{ ... }:
+{
+  services.signald.enable = true;
+
+  # TODO: required?
+  # comes from <nix-matrix-appservices:examples/mautrix.nix>
+  systemd.services.matrix-as-signal = {
+    requires = [ "signald.service" ];
+    after = [ "signald.service" ];
+    unitConfig = {
+      JoinsNamespaceOf = "signald.service";
+    };
+    path = [
+      pkgs.ffmpeg # voice messages need `ffmpeg`
+    ];
+  };
+
+
+  services.matrix-appservices.services.signal = {
+    port = 29184;
+    format = "mautrix-python";
+    package = pkgs.mautrix-signal;
+    serviceConfig = {
+      StateDirectory = [ "matrix-as-signal" "signald" ];
+      SupplementaryGroups = [ "signald" ];
+    };
+    settings.signal = {
+      socket_path = config.services.signald.socketPath;
+      outgoing_attachment_dir = "/var/lib/signald/tmp";
+    };
+  };
+}