Component Container Masks Names of Internal Nodes of Components

[methylDragon]

Bug report

Required Info:

• Operating System:
  • Ubuntu 22.04, Ubuntu 20.04
• Installation type:
  • Binaries
• Version or commit hash:
  • rolling, 17.1.0
• DDS implementation:
  • Fast-RTPS
• Client library (if applicable):
  • rclcpp

Steps to reproduce issue

I made a minimal example!

See: https://github.com/methylDragon/bug-reports-and-pr-examples

Clone and build the repo

git clone -b rclcpp/2042-component-container-masking \
  https://github.com/methylDragon/bug-reports-and-pr-examples.git bug_ws
cd bug_ws

colcon build
source install/setup.bash

Now

# Terminal 1:
ros2 launch composition composition_demo.launch.py

# Terminal 2:
ros2 node list 

The launchfile launches two node components in a component container:

• Talker
• Listener

But in Talker's code, it spins up another internal node named "internal_node".

Expected behavior

The nodes listed should be:

$ ros2 node list
/launch_ros_XXXXXXX
/listener
/internal_node
/my_container
/talker

Actual behavior

The component container's name masks the internal node's name. This causes a whole host of issues relating to node name resolution (e.g. parameter resolution, etc.)

$ ros2 node list
WARNING: Be aware that are nodes in the graph that share an exact name, this can have unintended side effects.
/launch_ros_XXXXXXX
/listener
/my_container
/my_container
/talker

Additional information

I did some digging into this a couple months back, but I sort of forgot.. But the reason this happens is something about the node context/node options gets forgotten/ignored, which causes the internal node's name to get remapped to the component container's.

Also, this issue only occurs when using a component container, a normal manual composition works as expected:

# Terminal 1:
ros2 run composition manual_composition

# Terminal 2:
ros2 node list

Gives:

$ ros2 node list
/internal_node
/listener
/talker

[sloretz]

Does /internal_node still get renamed if it's node options get use_global_arguments set to false? I suspect it's picking up the name remap rule that was intended for the component manager.

https://github.com/ros2/rclcpp/blob/7c6785176a878cf16eb98995b732f405b9e776ed/rclcpp/include/rclcpp/node_options.hpp#L150-L160

[methylDragon]

Does /internal_node still get renamed if it's node options get use_global_arguments set to false? I suspect it's picking up the name remap rule that was intended for the component manager.

https://github.com/ros2/rclcpp/blob/7c6785176a878cf16eb98995b732f405b9e776ed/rclcpp/include/rclcpp/node_options.hpp#L150-L160

It does not and the issue goes away :o Is there a way to make this the default behavior?

Edit: It is a bad idea to make this the default behavior.