Error while launching thev velodyne driver from ros2-galactic

[abhilash1998]

Please complete the following information:

• OS and Version: [e.g. Ubuntu 20.04]
• ROS Version: [e.g. Galactic]
• Built from Source or Downloaded from Official Repository: Built from source
• Version: [if from repository, give version from sudo dpkg -s ros-$ROS_VERSION-velodyne, if from source, give commit hash]

Describe the bug
I am using docker of ros-galactic and after git cloning the galactic branch of the velodyne and building I get the following error
InvalidLaunchFileError: Caught exception when trying to load file of format [py]: init() missing 1 required keyword-only argument: 'executable'
when running ros2 launch velodyne_driver velodyne_driver_node-VLP16-launch.py

To Reproduce
Steps to reproduce the behavior:

1. Create a docker with ubuntu 20 then install ros galactic in it.
2. Create a workspace
3. git clone --branch galactic-devel https://github.com/ros-drivers/velodyne.git
4. colcon build the workspace
5. source the workspace and run - ros2 launch velodyne_driver velodyne_driver_node-VLP16-launch.py

[JWhitleyWork]

@abhilash1998 Can you please clarify? There is no launch file called velodyne_driver_node-VLP16-launch.py in the galactic-devel branch, only velodyne_convert or velodyne_transform.

[TZECHIN6]

@abhilash1998 you can either manually change it or use ros2 branch instead.

[abhilash1998]

@abhilash1998 Can you please clarify? There is no launch file called velodyne_driver_node-VLP16-launch.py in the galactic-devel branch, only velodyne_convert or velodyne_transform.

Hey @JWhitleyWork
This is the command
ros2 launch velodyne velodyne-all-nodes-VLP16-launch.py

I fixed it, the fix was to convert -
“””
velodyne_driver_node = launch_ros.actions.Node(package='velodyne_driver',
node_executable='velodyne_driver_node',
output='both',
parameters=[driver_params_file]). “””

to

“””
velodyne_driver_node = launch_ros.actions.Node(package='velodyne_driver',
executable='velodyne_driver_node',
output='both',
parameters=[driver_params_file])”””

as the syntax changed from “node_executable” to “executable” in galactic.

Similar changes need to be done in the other launch files.

Thanks

[JWhitleyWork]

Unfortunately (sorry for being late on this), galactic is now EOL. It looks like back-porting #435 would fix this issue but I could not release a new binary version. Please create a PR to back-port #435 if you would like this feature in the repo and I will approve it.