Remove node_name from <ros> SDF tag (#804)

* Rename Node::Create to Node::Get

* Node::Get without node name

* Remove node_name support from SDF

* wip get name from plugin name

* Remove node name argument (will be inferred from sdf)

* fix tests and implement static shared node

* Adding test file

gazebo_plugins/include/gazebo_plugins/gazebo_ros_force.hpp

@@ -35,9 +35,6 @@ class GazeboRosForcePrivate;
 
       <ros>
 
-        <!-- Override default node name -->
-        <node_name>force_test_node</node_name>
-
         <!-- Add a namespace -->
         <namespace>/test</namespace>
 

gazebo_plugins/include/gazebo_plugins/gazebo_ros_joint_state_publisher.hpp

@@ -52,9 +52,6 @@ class GazeboRosJointStatePublisherPrivate;
 
       <ros>
 
-        <!-- Override default node name -->
-        <node_name>my_joint_state_publisher</node_name>
-
         <!-- Add a namespace -->
         <namespace>/ny_namespace</namespace>
 

gazebo_plugins/src/gazebo_ros_force.cpp

@@ -73,7 +73,7 @@ void GazeboRosForce::Load(gazebo::physics::ModelPtr model, sdf::ElementPtr sdf)
   }
 
   // Subscribe to wrench messages
-  impl_->ros_node_ = gazebo_ros::Node::Create("gazebo_ros_force", sdf);
+  impl_->ros_node_ = gazebo_ros::Node::Get(sdf);
 
   impl_->wrench_sub_ = impl_->ros_node_->create_subscription<geometry_msgs::msg::Wrench>(
     "gazebo_ros_force", std::bind(&GazeboRosForce::OnRosWrenchMsg, this,

gazebo_plugins/src/gazebo_ros_imu_sensor.cpp

@@ -58,7 +58,7 @@ GazeboRosImuSensor::~GazeboRosImuSensor()
 
 void GazeboRosImuSensor::Load(gazebo::sensors::SensorPtr _sensor, sdf::ElementPtr _sdf)
 {
-  impl_->ros_node_ = gazebo_ros::Node::Create("gazebo_ros_imu_sensor", _sdf);
+  impl_->ros_node_ = gazebo_ros::Node::Get(_sdf);
 
   impl_->sensor_ = std::dynamic_pointer_cast<gazebo::sensors::ImuSensor>(_sensor);
   if (!impl_->sensor_) {

gazebo_plugins/src/gazebo_ros_joint_state_publisher.cpp

@@ -85,7 +85,7 @@ GazeboRosJointStatePublisher::~GazeboRosJointStatePublisher()
 void GazeboRosJointStatePublisher::Load(gazebo::physics::ModelPtr model, sdf::ElementPtr sdf)
 {
   // ROS node
-  impl_->ros_node_ = gazebo_ros::Node::Create("gazebo_ros_joint_state_publisher", sdf);
+  impl_->ros_node_ = gazebo_ros::Node::Get(sdf);
 
   // Joints
   if (!sdf->HasElement("joint_name")) {

gazebo_plugins/src/gazebo_ros_ray_sensor.cpp

@@ -100,7 +100,7 @@ GazeboRosRaySensor::~GazeboRosRaySensor()
 void GazeboRosRaySensor::Load(gazebo::sensors::SensorPtr _sensor, sdf::ElementPtr _sdf)
 {
   // Create ros_node configured from sdf
-  impl_->ros_node_ = gazebo_ros::Node::Create("gazebo_ray_sensor", _sdf);
+  impl_->ros_node_ = gazebo_ros::Node::Get(_sdf);
 
   // Get tf frame for output
   impl_->frame_name_ = gazebo_ros::SensorFrameID(*_sensor, *_sdf);

gazebo_plugins/src/gazebo_ros_template.cpp

@@ -46,7 +46,7 @@ void GazeboRosTemplate::Load(gazebo::physics::ModelPtr model, sdf::ElementPtr sd
   // Create a GazeboRos node instead of a common ROS node.
   // Pass it SDF parameters so common options like namespace and remapping
   // can be handled.
-  impl_->ros_node_ = gazebo_ros::Node::Create("gazebo_ros_template", sdf);
+  impl_->ros_node_ = gazebo_ros::Node::Get(sdf);
 
   // The model pointer gives you direct access to the physics object,
   // for example:

gazebo_plugins/test/worlds/gazebo_ros_force.world

@@ -27,7 +27,6 @@
       </link>
       <plugin name="gazebo_ros_force" filename="libgazebo_ros_force.so">
         <ros>
-          <node_name>force_test_node</node_name>
           <namespace>/test</namespace>
           <argument>gazebo_ros_force:=force_test</argument>
         </ros>

gazebo_plugins/test/worlds/gazebo_ros_joint_state_publisher.world

@@ -68,7 +68,6 @@
       <plugin name="gazebo_ros_joint_state_publisher"
           filename="libgazebo_ros_joint_state_publisher.so">
         <ros>
-          <node_name>joint_state_publisher_test_node</node_name>
           <namespace>/test</namespace>
           <argument>joint_states:=joint_states_test</argument>
         </ros>

gazebo_plugins/test/worlds/gazebo_ros_ray_sensor.world

@@ -49,31 +49,27 @@
           <!-- Instance of ray plugin for each output type -->
           <plugin name="pc2" filename="libgazebo_ros_ray_sensor.so">
             <ros>
-              <node_name>pc2</node_name>
               <namespace>/ray</namespace>
               <argument>~/out:=pointcloud2</argument>
             </ros>
             <output_type>sensor_msgs/PointCloud2</output_type>
           </plugin>
           <plugin name="pc" filename="libgazebo_ros_ray_sensor.so">
             <ros>
-              <node_name>pc</node_name>
               <namespace>/ray</namespace>
               <argument>~/out:=pointcloud</argument>
             </ros>
             <output_type>sensor_msgs/PointCloud</output_type>
           </plugin>
           <plugin name="ls" filename="libgazebo_ros_ray_sensor.so">
             <ros>
-              <node_name>ls</node_name>
               <namespace>/ray</namespace>
               <argument>~/out:=laserscan</argument>
             </ros>
             <output_type>sensor_msgs/LaserScan</output_type>
           </plugin>
           <plugin name="range" filename="libgazebo_ros_ray_sensor.so">
             <ros>
-              <node_name>range</node_name>
               <namespace>/ray</namespace>
               <argument>~/out:=range</argument>
             </ros>
@@ -83,31 +79,27 @@
 <!-- Disabled while gpu laser is broken in gazebo9, see https://bitbucket.org/osrf/gazebo/issues/2486/conflicts-between-vertical-gpu-rays-and
           <plugin name="pc2_gpu" filename="libgazebo_ros_ray_sensor.so">
             <ros>
-              <node_name>pc2</node_name>
               <namespace>/gpu_ray</namespace>
               <argument>~/out:=pointcloud2</argument>
             </ros>
             <output_type>sensor_msgs/PointCloud2</output_type>
           </plugin>
           <plugin name="pc_gpu" filename="libgazebo_ros_ray_sensor.so">
             <ros>
-              <node_name>pc</node_name>
               <namespace>/gpu_ray</namespace>
               <argument>~/out:=pointcloud</argument>
             </ros>
             <output_type>sensor_msgs/PointCloud</output_type>
           </plugin>
           <plugin name="ls_gpu" filename="libgazebo_ros_ray_sensor.so">
             <ros>
-              <node_name>ls</node_name>
               <namespace>/gpu_ray</namespace>
               <argument>~/out:=laserscan</argument>
             </ros>
             <output_type>sensor_msgs/LaserScan</output_type>
           </plugin>
           <plugin name="range_gpu" filename="libgazebo_ros_ray_sensor.so">
             <ros>
-              <node_name>range</node_name>
               <namespace>/gpu_ray</namespace>
               <argument>~/out:=range</argument>
             </ros>

gazebo_plugins/worlds/gazebo_ros_force_demo.world

@@ -34,7 +34,6 @@
       </link>
       <plugin name="gazebo_ros_force" filename="libgazebo_ros_force.so">
         <ros>
-          <node_name>force_demo_node</node_name>
           <namespace>/demo</namespace>
           <argument>gazebo_ros_force:=force_demo</argument>
         </ros>

gazebo_plugins/worlds/gazebo_ros_joint_state_publisher_demo.world

@@ -20,7 +20,6 @@
       <plugin name="gazebo_ros_joint_state_publisher"
           filename="libgazebo_ros_joint_state_publisher.so">
         <ros>
-          <node_name>joint_state_publisher_demo_node</node_name>
           <namespace>/demo</namespace>
           <argument>joint_states:=joint_states_demo</argument>
         </ros>

gazebo_plugins/worlds/gazebo_ros_ray_sensor_demo.world

@@ -81,31 +81,27 @@
           <update_rate>1.0</update_rate>
           <plugin name="pc2" filename="libgazebo_ros_ray_sensor.so">
             <ros>
-              <node_name>pc2</node_name>
               <namespace>/ray</namespace>
               <argument>~/out:=pointcloud2</argument>
             </ros>
             <output_type>sensor_msgs/PointCloud2</output_type>
           </plugin>
           <plugin name="pc" filename="libgazebo_ros_ray_sensor.so">
             <ros>
-              <node_name>pc</node_name>
               <namespace>/ray</namespace>
               <argument>~/out:=pointcloud</argument>
             </ros>
             <output_type>sensor_msgs/PointCloud</output_type>
           </plugin>
           <plugin name="laserscan" filename="libgazebo_ros_ray_sensor.so">
             <ros>
-              <node_name>laserscan</node_name>
               <namespace>/ray</namespace>
               <argument>~/out:=laserscan</argument>
             </ros>
             <output_type>sensor_msgs/LaserScan</output_type>
           </plugin>
           <plugin name="range" filename="libgazebo_ros_ray_sensor.so">
             <ros>
-              <node_name>range</node_name>
               <namespace>/ray</namespace>
               <argument>~/out:=range</argument>
             </ros>
@@ -140,33 +136,29 @@
           </ray>
           <always_on>true</always_on>
           <update_rate>1.0</update_rate>
-          <plugin name="pc2" filename="libgazebo_ros_ray_sensor.so">
+          <plugin name="pc2_gpu" filename="libgazebo_ros_ray_sensor.so">
             <ros>
-              <node_name>pc2</node_name>
               <namespace>/gpu_ray</namespace>
               <argument>~/out:=pointcloud2</argument>
             </ros>
             <output_type>sensor_msgs/PointCloud2</output_type>
           </plugin>
-          <plugin name="pc" filename="libgazebo_ros_ray_sensor.so">
+          <plugin name="pc_gpu" filename="libgazebo_ros_ray_sensor.so">
             <ros>
-              <node_name>pc</node_name>
               <namespace>/gpu_ray</namespace>
               <argument>~/out:=pointcloud</argument>
             </ros>
             <output_type>sensor_msgs/PointCloud</output_type>
           </plugin>
-          <plugin name="laserscan" filename="libgazebo_ros_ray_sensor.so">
+          <plugin name="laserscan_gpu" filename="libgazebo_ros_ray_sensor.so">
             <ros>
-              <node_name>laserscan</node_name>
               <namespace>/gpu_ray</namespace>
               <argument>~/out:=laserscan</argument>
             </ros>
             <output_type>sensor_msgs/LaserScan</output_type>
           </plugin>
-          <plugin name="range" filename="libgazebo_ros_ray_sensor.so">
+          <plugin name="range_gpu" filename="libgazebo_ros_ray_sensor.so">
             <ros>
-              <node_name>range</node_name>
               <namespace>/gpu_ray</namespace>
               <argument>~/out:=range</argument>
             </ros>

gazebo_plugins/worlds/gazebo_ros_template_demo.world

@@ -8,7 +8,6 @@
       <static>true</static>
       <plugin name="gazebo_ros_template" filename="libgazebo_ros_template.so">
         <ros>
-          <node_name>demo_node</node_name>
           <namespace>/demo</namespace>
         </ros>
       </plugin>

gazebo_ros/include/gazebo_ros/node.hpp

@@ -42,39 +42,41 @@ class Node : public rclcpp::Node
   /// Destructor
   virtual ~Node();
 
-  /// Create a #gazebo_ros::Node and add it to the global #gazebo_ros::Executor.
+  /// Get a static node called "gazebo" which can be shared by several plugins.
   /**
    * \details This will call rclcpp::init if it hasn't been called yet.
-   * \param[in] node_name Name for the new node to create
-   * \return A shared pointer to a new #gazebo_ros::Node
+   * \details The node is created the first time this is called.
+   * \return A shared pointer to a #gazebo_ros::Node
    */
-  static SharedPtr Create(const std::string & node_name);
+  static SharedPtr Get();
 
-  /// Create a #gazebo_ros::Node and add it to the global #gazebo_ros::Executor.
+  /// Get reference to a #gazebo_ros::Node and add it to the global #gazebo_ros::Executor.
   /**
+   * \details This will create a new node; the node's name will be the same as the name argument
+   * on the <plugin> tag.
    * \details This will call rclcpp::init if it hasn't been called yet.
-   * \details Sets namespace, remappings, and parameters from SDF.
+   * \details Sets node name, namespace, remappings, and parameters from SDF.
    * SDF is in the form:
    * \code{.xml}
-   * <!-- Optional configurations for a plugin's Node -->
-   * <ros>
-   *  <!-- Name of node, only use if plugin is one node -->
-   *  <node_name>my_node</node_name>
-   *  <!-- Namespace of the node -->
-   *  <namespace>/my_ns</namespace>
-   *  <!-- Command line arguments sent to Node's constructor for remappings -->
-   *  <argument>my_topic:=new_topic</argument>
-   *  <argument>__name:=super_cool_node</argument>
-   *  <!-- Initial ROS params set for node -->
-   *  <parameter name="max_velocity" type="int">55</parameter>
-   *  <parameter name="publish_odom" type="bool">True</parameter>
-   * </ros>
+   * <!-- Node name will be the same as the plugin name -->
+   * <plugin name="my_node_name" filename="my_library.so">
+   *   <!-- Optional configurations for a plugin's Node -->
+   *   <ros>
+   *    <!-- Namespace of the node -->
+   *    <namespace>/my_ns</namespace>
+   *    <!-- Command line arguments sent to Node's constructor for remappings -->
+   *    <argument>my_topic:=new_topic</argument>
+   *    <argument>__name:=super_cool_node</argument>
+   *    <!-- Initial ROS params set for node -->
+   *    <parameter name="max_velocity" type="int">55</parameter>
+   *    <parameter name="publish_odom" type="bool">True</parameter>
+   *   </ros>
+   * </plugin>
    * \endcode
-   * \param[in] node_name Name of node to create
    * \param[in] _sdf An SDF element in the style above or containing a <ros> tag in the style above
    * \return A shared pointer to a new #gazebo_ros::Node
    */
-  static SharedPtr Create(const std::string & node_name, sdf::ElementPtr _sdf);
+  static SharedPtr Get(sdf::ElementPtr _sdf);
 
   /// Create a #gazebo_ros::Node and add it to the global #gazebo_ros::Executor.
   /**
@@ -118,6 +120,9 @@ class Node : public rclcpp::Node
   /// Points to an #gazebo_ros::Executor shared between all #gazebo_ros::Node instances
   static std::weak_ptr<Executor> static_executor_;
 
+  /// Points to a #gazebo_ros::Node which can be shared among several plugins.
+  static std::weak_ptr<Node> static_node_;
+
   /// Gets a logger to log information internal to the node
   static rclcpp::Logger internal_logger();
 };

gazebo_ros/src/gazebo_ros_init.cpp

@@ -52,7 +52,7 @@ void GazeboRosInit::Load(int argc, char ** argv)
   // Initialize ROS with arguments
   rclcpp::init(argc, argv);
 
-  impl_->ros_node_ = gazebo_ros::Node::Create("gazebo_ros_clock");
+  impl_->ros_node_ = gazebo_ros::Node::Get();
 
   // Offer transient local durability on the clock topic so that if publishing is infrequent (e.g.
   // the simulation is paused), late subscribers can receive the previously published message(s).

gazebo_ros/src/node.cpp

@@ -23,28 +23,30 @@ namespace gazebo_ros
 {
 
 std::weak_ptr<Executor> Node::static_executor_;
+std::weak_ptr<Node> Node::static_node_;
 std::mutex Node::lock_;
 
 Node::~Node()
 {
 }
 
-Node::SharedPtr Node::Create(const std::string & node_name, sdf::ElementPtr sdf)
+Node::SharedPtr Node::Get(sdf::ElementPtr sdf)
 {
-  // Get inner <ros> element if full plugin sdf was passed in
-  if (sdf->HasElement("ros")) {
-    sdf = sdf->GetElement("ros");
-  }
-
   // Initialize arguments
-  std::string name = node_name;
+  std::string name = "";
   std::string ns = "";
   std::vector<std::string> arguments;
   std::vector<rclcpp::Parameter> initial_parameters;
 
-  // Override name if tag is present
-  if (sdf->HasElement("node_name")) {
-    name = sdf->GetElement("node_name")->Get<std::string>();
+  // Get the name of the plugin as the name for the node.
+  if (!sdf->HasAttribute("name")) {
+    RCLCPP_WARN(internal_logger(), "Name of plugin not found.");
+  }
+  name = sdf->Get<std::string>("name");
+
+  // Get inner <ros> element if full plugin sdf was passed in
+  if (sdf->HasElement("ros")) {
+    sdf = sdf->GetElement("ros");
   }
 
   // Set namespace if tag is present
@@ -85,9 +87,16 @@ Node::SharedPtr Node::Create(const std::string & node_name, sdf::ElementPtr sdf)
     arguments, initial_parameters);
 }
 
-Node::SharedPtr Node::Create(const std::string & node_name)
+Node::SharedPtr Node::Get()
 {
-  return CreateWithArgs(node_name);
+  Node::SharedPtr node = static_node_.lock();
+
+  if (!node) {
+    node = CreateWithArgs("gazebo");
+    static_node_ = node;
+  }
+
+  return node;
 }
 
 rclcpp::Parameter Node::sdf_to_ros_parameter(sdf::ElementPtr const & sdf)