Add parameter to include hidden topics and services (ROS 2) (foxglove…

…#216)

### Public-Facing Changes

- Add parameter to include hidden topics and services (not included by
default)

### Description
Adds the new parameter `include_hidden` which controls if hidden topics
or services are advertised.

From
https://design.ros2.org/articles/topic_and_service_names.html#hidden-topic-or-service-names:

> Any topic or service name that contains any tokens (either namespaces
or a topic or service name) that start with an underscore (_) will be
considered hidden and tools may not show them unless explicitly asked.

README.md

@@ -76,11 +76,12 @@ Parameters are provided to configure the behavior of the bridge. These parameter
   * __client_topic_whitelist__: List of regular expressions ([ECMAScript grammar](https://en.cppreference.com/w/cpp/regex/ecmascript)) of whitelisted client-published topic names. Defaults to `[".*"]`.
  * __send_buffer_limit__: Connection send buffer limit in bytes. Messages will be dropped when a connection's send buffer reaches this limit to avoid a queue of outdated messages building up. Defaults to `10000000` (10 MB).
  * __use_compression__: Use websocket compression (permessage-deflate). Suited for connections with smaller bandwith, at the cost of additional CPU load.
+ * __capabilities__: List of supported [server capabilities](https://github.com/foxglove/ws-protocol/blob/main/docs/spec.md). Defaults to `[clientPublish,parameters,parametersSubscribe,services,connectionGraph]`.
  * (ROS 1) __max_update_ms__: The maximum number of milliseconds to wait in between polling `roscore` for new topics, services, or parameters. Defaults to `5000`.
  * (ROS 2) __num_threads__: The number of threads to use for the ROS node executor. This controls the number of subscriptions that can be processed in parallel. 0 means one thread per CPU core. Defaults to `0`.
  * (ROS 2) __min_qos_depth__: Minimum depth used for the QoS profile of subscriptions. Defaults to `1`. This is to set a lower limit for a subscriber's QoS depth which is computed by summing up depths of all publishers. See also [#208](https://github.com/foxglove/ros-foxglove-bridge/issues/208).
  * (ROS 2) __max_qos_depth__: Maximum depth used for the QoS profile of subscriptions. Defaults to `10`.
- * (ROS 2) __capabilities__: List of supported [server capabilities](https://github.com/foxglove/ws-protocol/blob/main/docs/spec.md). Defaults to `[clientPublish,parameters,parametersSubscribe,services,connectionGraph]`.
+ * (ROS 2) __include_hidden__: Include hidden topics and services. Defaults to `false`.
 
 ## Building from source
 

ros2_foxglove_bridge/include/foxglove_bridge/param_utils.hpp

@@ -22,6 +22,7 @@ constexpr char PARAM_PARAMETER_WHITELIST[] = "param_whitelist";
 constexpr char PARAM_USE_COMPRESSION[] = "use_compression";
 constexpr char PARAM_CAPABILITIES[] = "capabilities";
 constexpr char PARAM_CLIENT_TOPIC_WHITELIST[] = "client_topic_whitelist";
+constexpr char PARAM_INCLUDE_HIDDEN[] = "include_hidden";
 
 constexpr int64_t DEFAULT_PORT = 8765;
 constexpr char DEFAULT_ADDRESS[] = "0.0.0.0";

ros2_foxglove_bridge/launch/foxglove_bridge_launch.xml

@@ -14,6 +14,7 @@
   <arg name="send_buffer_limit"         default="10000000" />
   <arg name="use_sim_time"              default="false" />
   <arg name="capabilities"              default="[clientPublish,parameters,parametersSubscribe,services,connectionGraph]" />
+  <arg name="include_hidden"            default="false" />
 
   <node pkg="foxglove_bridge" exec="foxglove_bridge">
     <param name="port"                    value="$(var port)" />
@@ -31,5 +32,6 @@
     <param name="send_buffer_limit"       value="$(var send_buffer_limit)" />
     <param name="use_sim_time"            value="$(var use_sim_time)" />
     <param name="capabilities"            value="$(var capabilities)" />
+    <param name="include_hidden"          value="$(var include_hidden)" />
   </node>
 </launch>

ros2_foxglove_bridge/src/param_utils.cpp

@@ -139,6 +139,13 @@ void declareParameters(rclcpp::Node* node) {
   clientTopicWhiteListDescription.read_only = true;
   node->declare_parameter(PARAM_CLIENT_TOPIC_WHITELIST, std::vector<std::string>({".*"}),
                           paramWhiteListDescription);
+
+  auto includeHiddenDescription = rcl_interfaces::msg::ParameterDescriptor{};
+  includeHiddenDescription.name = PARAM_INCLUDE_HIDDEN;
+  includeHiddenDescription.type = rcl_interfaces::msg::ParameterType::PARAMETER_BOOL;
+  includeHiddenDescription.description = "Include hidden topics and services";
+  includeHiddenDescription.read_only = true;
+  node->declare_parameter(PARAM_INCLUDE_HIDDEN, false, includeHiddenDescription);
 }
 
 std::vector<std::regex> parseRegexStrings(rclcpp::Node* node,

ros2_foxglove_bridge/src/ros2_foxglove_bridge.cpp

@@ -30,6 +30,15 @@ using ClientPublications = std::unordered_map<foxglove::ClientChannelId, Publica
 using PublicationsByClient = std::map<ConnectionHandle, ClientPublications, std::owner_less<>>;
 using foxglove::isWhitelisted;
 
+namespace {
+inline bool isHiddenTopicOrService(const std::string& name) {
+  if (name.empty()) {
+    throw std::invalid_argument("Topic or service name can't be empty");
+  }
+  return name.front() == '_' || name.find("/_") != std::string::npos;
+}
+}  // namespace
+
 namespace foxglove_bridge {
 
 class FoxgloveBridge : public rclcpp::Node {
@@ -66,6 +75,7 @@ class FoxgloveBridge : public rclcpp::Node {
     const auto clientTopicWhiteList =
       this->get_parameter(PARAM_CLIENT_TOPIC_WHITELIST).as_string_array();
     const auto clientTopicWhiteListPatterns = parseRegexStrings(this, clientTopicWhiteList);
+    _includeHidden = this->get_parameter(PARAM_INCLUDE_HIDDEN).as_bool();
 
     const auto logHandler = std::bind(&FoxgloveBridge::logHandler, this, _1, _2);
     foxglove::ServerOptions serverOptions;
@@ -193,6 +203,11 @@ class FoxgloveBridge : public rclcpp::Node {
       const auto& topicName = topicNamesAndType.first;
       const auto& datatypes = topicNamesAndType.second;
 
+      // Ignore hidden topics if not explicitly included
+      if (!_includeHidden && isHiddenTopicOrService(topicName)) {
+        continue;
+      }
+
       // Ignore the topic if it is not on the topic whitelist
       if (isWhitelisted(topicName, _topicWhitelistPatterns)) {
         for (const auto& datatype : datatypes) {
@@ -326,6 +341,11 @@ class FoxgloveBridge : public rclcpp::Node {
         continue;
       }
 
+      // Ignore hidden services if not explicitly included
+      if (!_includeHidden && isHiddenTopicOrService(serviceName)) {
+        continue;
+      }
+
       // Ignore the service if it is not on the service whitelist
       if (!isWhitelisted(serviceName, _serviceWhitelistPatterns)) {
         continue;
@@ -448,6 +468,7 @@ class FoxgloveBridge : public rclcpp::Node {
   bool _useSimTime = false;
   std::vector<std::string> _capabilities;
   std::atomic<bool> _subscribeGraphUpdates = false;
+  bool _includeHidden = false;
 
   void subscribeHandler(foxglove::ChannelId channelId, ConnectionHandle hdl) {
     _handlerCallbackQueue->addCallback(std::bind(&FoxgloveBridge::subscribe, this, channelId, hdl));