chore(nebula_ros): specify library destination for install targets

[mbharatheesha]

PR Type

Improvement

Description

This PR introduces a minimal delta needed to enable the installation of shared libraries corresponding to the composable node targets for the differet ros wrappers into /opt/ros/<distro>/lib instead of /opt/ros/<distro>/x86_64-linux-gnu/.

This installation path matters when the ROS wrappers for the lidar drivers are used as composable nodes, the relevant shared libraries are reported as unavailable. Here are some details:

I created a binary release of this package locally using bloom using the following steps:
(Do a source build of nebula_ros package following the instructions on README)

apt-get install -qqy python-bloom fakeroot dpkg-dev debhelper
cd nebula_ros
bloom-generate rosdebian
fakeroot debian/rules binary

Without the changes in this PR

The lib<lidar_type>_ros_wrapper.so files get installed under /opt/ros/<distro>/lib/x86_64-linux-gnu/. And when I try to test the composable node versions of the ROS wrappers using:

ros2 component standalone nebula_ros HesaiRosWrapper

I get the following error:

[INFO] [1738699444.539630225] [standalone_container_51b647ce1865]: Load Library: /opt/ros/jazzy/lib/libhesai_ros_wrapper.so
[ERROR] [1738699444.539908988] [standalone_container_51b647ce1865]: Failed to load library: Could not load library dlopen error: /opt/ros/jazzy/lib/libhesai_ros_wrapper.so: cannot open shared object file: No such file or directory, at ./src/shared_library.c:99

It is the same error type for other ROS wrappers too.

With the changes in this PR

The lib<lidar_type>_ros_wrapper.so files get installed under /opt/ros/<distro>/lib. And when I try to test the composable node versions of the ROS wrappers using:

ros2 component standalone nebula_ros HesaiRosWrapper

The composable node is loaded successfully

[INFO] [1738699840.335771784] [standalone_container_639fe89b495c]: Load Library: /opt/ros/jazzy/lib/libhesai_ros_wrapper.so
[INFO] [1738699840.341811197] [standalone_container_639fe89b495c]: Found class: rclcpp_components::NodeFactoryTemplate<HesaiRosWrapper>
[INFO] [1738699840.341849698] [standalone_container_639fe89b495c]: Instantiate class: rclcpp_components::NodeFactoryTemplate<HesaiRosWrapper>

Review Procedure

The errors I mention in the description are reproducible with the commands I have posted above. Then, with the changes in this PR, one can verify that the shared libraries are installed at the location desired by the composable node infrastructure i.e., /opt/ros/<distro>/lib.

Remarks

There are a few additional changes I can think of which are mostly with improving readability. For example"

• the following lines in CMakeLists.txt of nebula_ros:

install(TARGETS hesai_ros_wrapper EXPORT export_hesai_ros_wrapper LIBRARY DESTINATION lib)
install(TARGETS velodyne_ros_wrapper EXPORT export_velodyne_ros_wrapper LIBRARY DESTINATION lib)
install(TARGETS robosense_ros_wrapper EXPORT export_robosense_ros_wrapper LIBRARY DESTINATION lib)
install(TARGETS continental_ars548_ros_wrapper EXPORT export_continental_ars548_ros_wrapper LIBRARY DESTINATION lib)
install(TARGETS continental_srr520_ros_wrapper EXPORT export_continental_srr520_ros_wrapper LIBRARY DESTINATION lib)

can be consolidated to:

install (
  TARGETS
  continental_ars548_ros_wrapper
  continental_srr520_ros_wrapper
  hesai_ros_wrapper
  robosense_ros_wrapper
  velodyne_ros_wrapper
  EXPORT export_${PROJECT_NAME}
  LIBRARY DESTINATION lib
)

ament_export_targets(export_${PROJECT_NAME})

• the composable nodes registration in <lidar_type>_ros_wrapper.cpp could be modifed in accordance with common practice across other ROS2 packages like this:

RCLCPP_COMPONENTS_REGISTER_NODE(nebula::ros::<LidarType>RosWrapper)

And accordingly register them in the CMakeLists.txt as:

rclcpp_components_register_node(hesai_ros_wrapper
        PLUGIN "nebula::ros::HesaiRosWrapper"
        EXECUTABLE hesai_ros_wrapper_node
)

• And perhaps also add an example launch file using composable nodes

Pre-Review Checklist for the PR Author

PR Author should check the checkboxes below when creating the PR.

• Assign PR to reviewer

Checklist for the PR Reviewer

Reviewers should check the checkboxes below before approval.

• Commits are properly organized and messages are according to the guideline
• (Optional) Unit tests have been written for new behavior
• PR title describes the changes

Post-Review Checklist for the PR Author

PR Author should check the checkboxes below before merging.

• All open points are addressed and tracked via issues or tickets

CI Checks

• Build and test for PR: Required to pass before the merge.

[mbharatheesha]

@mojomex It seems I cannot assign a reviewer as requested by the PR template. So, I looked at the most recent author on the nebula_ros package and I tagged you. Kindly let me know if I should do this differently.

[mojomex]

Thank you for the PR, I'll have a look in the coming days!

[Timple]

For what it's worth, it works in practice 🙂

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 27.14%. Comparing base (44e6c88) to head (11f8669).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #261      +/-   ##
==========================================
- Coverage   28.89%   27.14%   -1.75%     
==========================================
  Files         105      105              
  Lines        9465     9271     -194     
  Branches     3115     2057    -1058     
==========================================
- Hits         2735     2517     -218     
- Misses       6240     6334      +94     
+ Partials      490      420      -70     

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[mojomex]

Thank you for the PR, much appreciated!
I confirmed it's working and that it's essentially the same thing ament_cmake_auto is also doing.

[mbharatheesha]

And thank you guys for this package!