Bridge as a gz sim system [rolling]

[caguero]

🎉 New feature

Summary

This PR runs the ROS<->Gz bridge as a gz sim system. It's targeting ROS 2 rolling. I'll create a separate PR with some updates that we discussed offline.

Test it

ros2 launch ros_gz_sim_demos ros_gz.launch.py

Verify the output to confirm that two topics are bridged:

[ruby $(which ign) gazebo-1] [INFO] [1708634732.070359776] [ros_gz_bridge]: Creating ROS->GZ Bridge: [ros_chatter (std_msgs/msg/String) -> gz_chatter (ignition.msgs.StringMsg)] (Lazy 1)
[ruby $(which ign) gazebo-1] [INFO] [1708634732.071384449] [ros_gz_bridge]: Creating GZ->ROS Bridge: [gz_chatter (ignition.msgs.StringMsg) -> ros_chatter (std_msgs/msg/String)] (Lazy 0)

Then, you should see a ROS topic /ros_chatter:

caguero@cold:~/ros_gz_ws$ ros2 topic list
/parameter_events
/ros_chatter
/rosout

Checklist

• [x] Signed all commits for DCO
• [ ] Added tests
• [x] Added example and/or tutorial
• [ ] Updated documentation (as needed)
• [ ] Updated migration guide (as needed)
• [ ] Consider updating Python bindings (if the library has them)
• [ ] codecheck passed (See contributing)
• [ ] All tests passed (See test coverage)
• [ ] While waiting for a review on your PR, please help review another open pull request to support the maintainers

Note to maintainers: Remember to use Squash-Merge and edit the commit message to match the pull request summary while retaining Signed-off-by messages.

[caguero]

@ahcorde , do you know if these tests are supposed to compile? It seems a problem sourcing setup.bash in rolling.

[azeey]

Can you also fix DCO?

[caguero]

Can you also fix DCO?

Fixed

[azeey]

@caguero Do we want to close this one now that the composable nodes PRs are merged?