Expose node options to controller manager (#942)

Signed-off-by: methylDragon <[email protected]>

Author: methylDragon

controller_manager/doc/images/global_general_remap.png

@@ -119,6 +119,35 @@ There are two scripts to interact with controller manager from launch files:
       -c CONTROLLER_MANAGER, --controller-manager CONTROLLER_MANAGER
                             Name of the controller manager ROS node
 
+Using the Controller Manager in a Process
+-----------------------------------------
+
+The ``ControllerManager`` may also be instantiated in a process as a class, but proper care must be taken when doing so.
+The reason for this is because the ``ControllerManager`` class inherits from ``rclcpp::Node``.
+
+If there is more than one Node in the process, global node name remap rules can forcibly change the ``ControllerManager's`` node name as well, leading to duplicate node names.
+This occurs whether the Nodes are siblings or exist in a hierarchy.
+
+.. image:: images/global_general_remap.png
+
+The workaround for this is to specify another node name remap rule in the ``NodeOptions`` passed to the ``ControllerManager`` node (causing it to ignore the global rule), or ensure that any remap rules are targeted to specific nodes.
+
+.. image:: images/global_specific_remap.png
+
+..
+  TODO: (methylDragon) Update the proposed solution when https://github.com/ros2/ros2/issues/1377 is resolved
+
+.. code-block:: cpp
+
+    auto options = controller_manager::get_cm_node_options();
+      options.arguments({
+        "--ros-args",
+        "--remap", "_target_node_name:__node:=dst_node_name",
+        "--log-level", "info"});
+
+      auto cm = std::make_shared<controller_manager::ControllerManager>(
+        executor, "_target_node_name", "some_optional_namespace", options);
+
 Concepts
 -----------
 

controller_manager/doc/images/global_specific_remap.png

@@ -56,6 +56,8 @@ namespace controller_manager
 {
 using ControllersListIterator = std::vector<controller_manager::ControllerSpec>::const_iterator;
 
+rclcpp::NodeOptions get_cm_node_options();
+
 class ControllerManager : public rclcpp::Node
 {
 public:
@@ -67,13 +69,15 @@ class ControllerManager : public rclcpp::Node
     std::unique_ptr<hardware_interface::ResourceManager> resource_manager,
     std::shared_ptr<rclcpp::Executor> executor,
     const std::string & manager_node_name = "controller_manager",
-    const std::string & namespace_ = "");
+    const std::string & namespace_ = "",
+    const rclcpp::NodeOptions & options = get_cm_node_options());
 
   CONTROLLER_MANAGER_PUBLIC
   ControllerManager(
     std::shared_ptr<rclcpp::Executor> executor,
     const std::string & manager_node_name = "controller_manager",
-    const std::string & namespace_ = "");
+    const std::string & namespace_ = "",
+    const rclcpp::NodeOptions & options = get_cm_node_options());
 
   CONTROLLER_MANAGER_PUBLIC
   virtual ~ControllerManager() = default;

controller_manager/doc/userdoc.rst

@@ -133,8 +133,8 @@ rclcpp::NodeOptions get_cm_node_options()
 
 ControllerManager::ControllerManager(
   std::shared_ptr<rclcpp::Executor> executor, const std::string & manager_node_name,
-  const std::string & namespace_)
-: rclcpp::Node(manager_node_name, namespace_, get_cm_node_options()),
+  const std::string & namespace_, const rclcpp::NodeOptions & options)
+: rclcpp::Node(manager_node_name, namespace_, options),
   resource_manager_(std::make_unique<hardware_interface::ResourceManager>()),
   diagnostics_updater_(this),
   executor_(executor),
@@ -167,8 +167,8 @@ ControllerManager::ControllerManager(
 ControllerManager::ControllerManager(
   std::unique_ptr<hardware_interface::ResourceManager> resource_manager,
   std::shared_ptr<rclcpp::Executor> executor, const std::string & manager_node_name,
-  const std::string & namespace_)
-: rclcpp::Node(manager_node_name, namespace_, get_cm_node_options()),
+  const std::string & namespace_, const rclcpp::NodeOptions & options)
+: rclcpp::Node(manager_node_name, namespace_, options),
   resource_manager_(std::move(resource_manager)),
   diagnostics_updater_(this),
   executor_(executor),