Add ROS namespaces to GZ topics

[Kotochleb]

🎉 New feature

Summary

This PR adds the ability to apply ROS node namespace onto GZ topics. This adds option for global namespaces, private namespaces and should also work for substitutions.

I believe this feature later could be easily ported to Iron and Rolling.

As it is an API breaking feature, I also introduced a new ROS parameter, preserving backward compatibility.

Test it

In the config_file YAML file, create topics as:

- topic_name: "chatter"
  ros_type_name: "std_msgs/msg/String"
  gz_type_name: "gz.msgs.StringMsg"
  direction: ROS_TO_GZ

- topic_name: "/chatter_global"
  ros_type_name: "std_msgs/msg/String"
  gz_type_name: "gz.msgs.StringMsg"
  direction: ROS_TO_GZ

- topic_name: "~/chatter_private_ns"
  ros_type_name: "std_msgs/msg/String"
  gz_type_name: "gz.msgs.StringMsg"
  direction: ROS_TO_GZ

- ros_topic_name: "chatter_ros_ns"
  gz_topic_name: "/chatter_ign_global"
  ros_type_name: "std_msgs/msg/String"
  gz_type_name: "gz.msgs.StringMsg"
  direction: ROS_TO_GZ

This should create ROS topics:

$ ros2 topic list
/my_namespace/chatter
/chatter_global
/my_namespace/ros_gz_bridge/chatter_private_ns
/my_namespace/chatter_ros_ns

And GZ topics:

$ ign topic --list
/my_namespace/chatter
/chatter_global
/my_namespace/ros_gz_bridge/chatter_private_ns
/chatter_ign_global

[Kotochleb]

@ahcorde I applied your suggestions and signed the commits

[azeey]

hmm, not sure why this is trying to run Rpr__ros_gz__ubuntu_noble_amd64 . It should be testing with Humble on Jammy.

[Kotochleb]

@azeey do you think I should just wait for the CI to be solved on your side? It doesn't seem to be broken by my changes

[azeey]

@azeey do you think I should just wait for the CI to be solved on your side? It doesn't seem to be broken by my changes

Yes, this is unrelated to your PR. Hopefully, we'll have a fix soon.

[Kotochleb]

@ahcorde I added new section about the remapping to the README.md. I also sort of allowed myself to change source commands to have humble instead of galactic, as this is humble branch. Since it is a very minor change and I am already making changes in the README, I thought it will be fine to push it with this PR.

[ahcorde]

@Kotochleb thank you for your contribution, do you have some time to do the forward port in iron and rolling?

[Kotochleb]

@ahcorde you are welcome. I would have time, but it will take me a few more days, as this feature for Humble was something I needed right now. Hopefully I will submit the PRs till end of this week.

[ahcorde]

backports

• https://github.com/gazebosim/ros_gz/pull/517
• https://github.com/gazebosim/ros_gz/pull/516