feat(conduit): Refactor matrix appservices and add matrix-hookshot

configuration/default.nix

@@ -17,7 +17,7 @@
 
     ./services/backups.nix
     ./services/battery-manager.nix
-    ./services/conduit.nix
+    ./services/conduit
     ./services/crowdsec.nix
     ./services/foundryvtt.nix
     ./services/gitea.nix

configuration/services/conduit/default.nix

@@ -1,5 +1,4 @@
 {
-  pkgs,
   config,
   lib,
   ...
@@ -12,6 +11,11 @@ let
   turn-realm = "turn.${config.services.nginx.domain}";
 in
 {
+  imports = [
+    ./heisenbridge.nix
+    ./matrix-hookshot.nix
+  ];
+
   services.matrix-conduit = {
     enable = true;
     settings.global = {
@@ -40,91 +44,6 @@ in
     };
   };
 
-  systemd.services.heisenbridge =
-    let
-      replaceSecretBin = "${pkgs.replace-secret}/bin/replace-secret";
-      registrationFile = builtins.toFile "heisenbridge-registration.yaml" (
-        builtins.toJSON {
-          id = "heisenbridge";
-          url = "http://127.0.0.1:9898";
-          as_token = "@AS_TOKEN@";
-          hs_token = "@HS_TOKEN@";
-          rate_limited = false;
-          sender_localpart = "heisenbridge";
-          namespaces = {
-            users = [
-              {
-                regex = "@irc_.*";
-                exclusive = true;
-              }
-              {
-                regex = "@heisenbridge:.*";
-                exclusive = true;
-              }
-            ];
-            aliases = [ ];
-            rooms = [ ];
-          };
-        }
-      );
-
-      # TODO(tlater): Starting with systemd 253 it will become possible
-      # to do the credential setup as part of ExecStartPre/preStart
-      # instead.
-      #
-      # This will also make it possible to actually set caps on the
-      # heisenbridge process using systemd, so that we can run the
-      # identd process.
-      execScript = pkgs.writeShellScript "heisenbridge" ''
-        cp ${registrationFile} "$RUNTIME_DIRECTORY/heisenbridge-registration.yaml"
-        chmod 600 $RUNTIME_DIRECTORY/heisenbridge-registration.yaml
-        ${replaceSecretBin} '@AS_TOKEN@' "$CREDENTIALS_DIRECTORY/heisenbridge_as-token" "$RUNTIME_DIRECTORY/heisenbridge-registration.yaml"
-        ${replaceSecretBin} '@HS_TOKEN@' "$CREDENTIALS_DIRECTORY/heisenbridge_hs-token" "$RUNTIME_DIRECTORY/heisenbridge-registration.yaml"
-        chmod 400 $RUNTIME_DIRECTORY/heisenbridge-registration.yaml
-
-        ${pkgs.heisenbridge}/bin/heisenbridge \
-            --config $RUNTIME_DIRECTORY/heisenbridge-registration.yaml \
-            --owner @tlater:matrix.tlater.net \
-            'http://localhost:${toString cfg.settings.global.port}'
-      '';
-    in
-    {
-      description = "Matrix<->IRC bridge";
-      wantedBy = [ "multi-user.target" ];
-      after = [ "conduit.service" ];
-
-      serviceConfig = {
-        Type = "simple";
-
-        LoadCredential = "heisenbridge:/run/secrets/heisenbridge";
-
-        ExecStart = execScript;
-
-        DynamicUser = true;
-        RuntimeDirectory = "heisenbridge";
-        RuntimeDirectoryMode = "0700";
-
-        RestrictNamespaces = true;
-        PrivateUsers = true;
-        ProtectHostname = true;
-        ProtectClock = true;
-        ProtectKernelTunables = true;
-        ProtectKernelModules = true;
-        ProtectKernelLogs = true;
-        ProtectControlGroups = true;
-        RestrictAddressFamilies = [ "AF_INET AF_INET6" ];
-        LockPersonality = true;
-        RestrictRealtime = true;
-        ProtectProc = "invisible";
-        ProcSubset = "pid";
-        UMask = 77;
-
-        # For the identd port
-        # CapabilityBoundingSet = ["CAP_NET_BIND_SERVICE"];
-        # AmbientCapabilities = ["CAP_NET_BIND_SERVICE"];
-      };
-    };
-
   # Pass in the TURN secret via EnvironmentFile, not supported by
   # upstream module currently.
   #

configuration/services/conduit/heisenbridge.nix

@@ -0,0 +1,78 @@
+{
+  pkgs,
+  lib,
+  config,
+  ...
+}:
+let
+  conduitCfg = config.services.matrix-conduit;
+  matrixLib = pkgs.callPackage ./lib.nix { };
+in
+{
+  systemd.services.heisenbridge =
+    let
+      registration = matrixLib.writeRegistrationScript {
+        id = "heisenbridge";
+        url = "http://127.0.0.1:9898";
+        sender_localpart = "heisenbridge";
+
+        namespaces = {
+          users = [
+            {
+              regex = "@irc_.*";
+              exclusive = true;
+            }
+            {
+              regex = "@heisenbridge:.*";
+              exclusive = true;
+            }
+          ];
+
+          aliases = [ ];
+          rooms = [ ];
+        };
+      };
+    in
+    {
+      description = "Matrix<->IRC bridge";
+      wantedBy = [ "multi-user.target" ];
+      after = [ "conduit.service" ];
+
+      serviceConfig = {
+        Type = "exec";
+
+        LoadCredential = "heisenbridge:/run/secrets/heisenbridge";
+
+        inherit (registration) ExecStartPre;
+        ExecStart = lib.concatStringsSep " " [
+          "${lib.getExe pkgs.heisenbridge}"
+          "--config \${RUNTIME_DIRECTORY}/heisenbridge-registration.yaml"
+          "--owner @tlater:matrix.tlater.net"
+          "http://localhost:${toString conduitCfg.settings.global.port}"
+        ];
+
+        DynamicUser = true;
+        RuntimeDirectory = "heisenbridge";
+        RuntimeDirectoryMode = "0700";
+
+        RestrictNamespaces = true;
+        PrivateUsers = true;
+        ProtectHostname = true;
+        ProtectClock = true;
+        ProtectKernelTunables = true;
+        ProtectKernelModules = true;
+        ProtectKernelLogs = true;
+        ProtectControlGroups = true;
+        RestrictAddressFamilies = [ "AF_INET AF_INET6" ];
+        LockPersonality = true;
+        RestrictRealtime = true;
+        ProtectProc = "invisible";
+        ProcSubset = "pid";
+        UMask = 77;
+
+        # For the identd port
+        # CapabilityBoundingSet = [ "CAP_NET_BIND_SERVICE" ];
+        # AmbientCapabilities = [ "CAP_NET_BIND_SERVICE" ];
+      };
+    };
+}

configuration/services/conduit/lib.nix

@@ -0,0 +1,67 @@
+{
+  lib,
+  writeShellScript,
+  formats,
+  replace-secret,
+}:
+let
+  replaceSecretBin = "${lib.getExe replace-secret}";
+in
+{
+  # Write a script that will set up the service's registration.yaml
+  # with secrets from systemd credentials.
+  #
+  # The credentials should be named `${id}_as-token` and
+  # `${id}_hs-token`.
+  #
+  # This registration file needs to be manually added to conduit by
+  # messaging the admin with the yaml file.
+  #
+  # TODO(tlater): Conduwuit seems to support a CLI interface for this,
+  # may want to migrate to that sometime.
+  writeRegistrationScript =
+    {
+      id, # Must be unique among all registered appservices/bots
+      url, # The URL on which the service listens
+      sender_localpart,
+      rate_limited ? false,
+      namespaces ? {
+        aliases = [ ];
+        rooms = [ ];
+        users = [ ];
+      },
+      extraSettings ? { },
+      # The location to place the file; assumes systemd runtime dir
+      runtimeRegistration ? "$RUNTIME_DIRECTORY/${id}-registration.yaml",
+    }:
+    let
+      registrationFile = (formats.yaml { }).generate "${id}-registration.yaml" (
+        {
+          inherit
+            id
+            url
+            sender_localpart
+            rate_limited
+            namespaces
+            ;
+
+          as_token = "@AS_TOKEN@";
+          hs_token = "@HS_TOKEN@";
+        }
+        // extraSettings
+      );
+    in
+    {
+      inherit runtimeRegistration;
+      ExecStartPre = writeShellScript "${id}-registration-setup.sh" ''
+        cp -f ${registrationFile} "${runtimeRegistration}"
+        chmod 600 "${runtimeRegistration}"
+
+        # Write actual secrets into config
+        ${replaceSecretBin} '@AS_TOKEN@' "$CREDENTIALS_DIRECTORY/${id}_as-token" "${runtimeRegistration}"
+        ${replaceSecretBin} '@HS_TOKEN@' "$CREDENTIALS_DIRECTORY/${id}_hs-token" "${runtimeRegistration}"
+
+        chmod 400 "${runtimeRegistration}"
+      '';
+    };
+}

configuration/services/conduit/matrix-hookshot.nix

@@ -0,0 +1,134 @@
+{
+  pkgs,
+  lib,
+  config,
+  ...
+}:
+let
+  matrixLib = pkgs.callPackage ./lib.nix { };
+
+  cfg = config.services.matrix-hookshot;
+  conduitCfg = config.services.matrix-conduit;
+
+  domain = conduitCfg.settings.global.server_name;
+
+  registration = matrixLib.writeRegistrationScript {
+    id = "matrix-hookshot";
+    url = "http://127.0.0.1:9993";
+    sender_localpart = "hookshot";
+
+    namespaces = {
+      aliases = [ ];
+      rooms = [ ];
+      users = [
+        {
+          regex = "@${cfg.settings.generic.userIdPrefix}.*:${domain}";
+          exclusive = true;
+        }
+      ];
+    };
+
+    runtimeRegistration = "${cfg.registrationFile}";
+  };
+in
+{
+  systemd.services.matrix-hookshot = {
+    serviceConfig = {
+      Type = lib.mkForce "exec";
+
+      LoadCredential = "matrix-hookshot:/run/secrets/matrix-hookshot";
+      inherit (registration) ExecStartPre;
+
+      # Some library in matrix-hookshot wants a home directory
+      Environment = [ "HOME=/run/matrix-hookshot" ];
+
+      DynamicUser = true;
+      StateDirectory = "matrix-hookshot";
+      RuntimeDirectory = "matrix-hookshot";
+      RuntimeDirectoryMode = "0700";
+
+      RestrictNamespaces = true;
+      PrivateUsers = true;
+      ProtectHostname = true;
+      ProtectClock = true;
+      ProtectKernelTunables = true;
+      ProtectKernelModules = true;
+      ProtectKernelLogs = true;
+      ProtectControlGroups = true;
+      RestrictAddressFamilies = [ "AF_INET AF_INET6" ];
+      LockPersonality = true;
+      RestrictRealtime = true;
+      ProtectProc = "invisible";
+      ProcSubset = "pid";
+      UMask = 77;
+    };
+  };
+
+  services.matrix-hookshot = {
+    enable = true;
+
+    serviceDependencies = [
+      "conduit.service"
+    ];
+
+    registrationFile = "/run/matrix-hookshot/registration.yaml";
+
+    settings = {
+      bridge = {
+        inherit domain;
+        url = "http://localhost:${toString conduitCfg.settings.global.port}";
+        mediaUrl = conduitCfg.settings.global.well_known.client;
+        port = 9993;
+        bindAddress = "127.0.0.1";
+      };
+
+      bot.displayname = "Hookshot";
+
+      generic = {
+        enabled = true;
+        outbound = false;
+        # Only allow webhooks from localhost for the moment
+        urlPrefix = "http://127.0.0.1:9000/webhook";
+        userIdPrefix = "_webhooks_";
+      };
+
+      permissions = [
+        {
+          actor = "matrix.tlater.net";
+          services = [
+            {
+              service = "*";
+              level = "notifications";
+            }
+          ];
+        }
+        {
+          actor = "@tlater:matrix.tlater.net";
+          services = [
+            {
+              service = "*";
+              level = "admin";
+            }
+          ];
+        }
+      ];
+
+      listeners = [
+        {
+          port = 9000;
+          resources = [
+            "webhooks"
+          ];
+        }
+        {
+          port = 9001;
+          resources = [
+            "metrics"
+          ];
+        }
+      ];
+
+      metrics.enable = true;
+    };
+  };
+}

configuration/services/metrics/victoriametrics.nix

@@ -26,6 +26,10 @@
             config.security.crowdsec.remediationComponents.firewallBouncer.settings.prometheus.listen_port;
         in
         [ "${address}:${toString port}" ];
+
+      # Configured in the hookshot listeners, but it's hard to filter
+      # the correct values out of that config.
+      matrixHookshot.targets = [ "127.0.0.1:9001" ];
     };
   };
 }

configuration/sops.nix

@@ -35,6 +35,10 @@
       "heisenbridge/as-token" = { };
       "heisenbridge/hs-token" = { };
 
+      # Matrix-hookshot
+      "matrix-hookshot/as-token" = { };
+      "matrix-hookshot/hs-token" = { };
+
       # Nextcloud
       "nextcloud/tlater" = {
         owner = "nextcloud";