Doesn't work with ROS2 Humble

[Ankur-singh]

Description For my research project, I am trying to using roslibpy with ROS2 Humble. I followed this doc to install ROS2. I am able to run the listener and talker nodes without any error.

Then I created listener.py and talker.py by following the example from roslibpy. I am getting multiple errors in python3. I think, the package and its dependencies are meant to work with python2 only.

On the ROS side, I tried installing and launching the rosbridge_suite as suggested here. Note: I replaced "kinetic" with "humble". But I am getting errors like Unable to locate: ros-humble-tf2-web-republisher. And also, I am not able to launch rosbridge_server.

Any help would be greatly appreciated.

System:

• OS: Ubuntu 22.04
• Python version: 3.8, 3.10
• Python package manager: pip

[gonzalocasas]

On the ROS side, I tried installing and launching the rosbridge_suite as suggested here. Note: I replaced "kinetic" with "humble". But I am getting errors like Unable to locate: ros-humble-tf2-web-republisher. And also, I am not able to launch rosbridge_server.

The web republisher might not be that important, but without the rosbridge_server, it is impossible to connect to ROS with roslibpy. Please make sure that you have that running first, and then update this issue with your findings. I believe after you solve that, this issue will be gone.

[Ankur-singh]

Thank you @gonzalocasas for the prompt response. I tried install rosbridge_server using the following command

sudo apt install ros-humble-rosbridge-server

After a few attempts it ran successfully. Then I resourced ROS and tried launching it using

ros2 launch rosbridge_server rosbridge_websocket.launch

But I got the following error

file 'rosbridge_websocket.launch' was not found in the share directory of package 'rosbridge_server' which is at '/opt/ros/humble/share/rosbridge_server'

I am new to ROS, so I am not sure what it means. I tried exploring the /opt/ros/humble/share/rosbridge_server/ directory. I can see a launch directory with rosbridge_websocket_launch.xml file. I don't know what's wrong and what else to look for.

[koichirokato]

When executing ROS launch, the file name should be specified directly. The launch file name has changed between ROS1 and ROS2. If you run below command, you can start rosbridge server.

ros2 launch rosbridge_server rosbridge_websocket_launch.xml

[gonzalocasas]

@Ankur-singh if I understand this right, this one has been solved by starting the ros bridge using the command above, right?

[ChiaChing-Yen]

@gonzalocasas

I encountered the same issue when following some ROS 2 tutorials online.

When executing ROS launch, the file name should be specified directly. The launch file name has changed between ROS1 and ROS2. If you run below command, you can start rosbridge server.

ros2 launch rosbridge_server rosbridge_websocket_launch.xml

koichirokato's solution worked for me. This issue occurred due to incorrect syntax when launching the rosbridge-server. I tested the listener and talker nodes from the examples in the documentation, and they worked smoothly.

My setup:

• ROS 2 Humble on Ubuntu 22.04
• roslibpy 1.7.0

[gonzalocasas]

Great, thanks! @ChiaChing-Yen That means we can close this, right?

[ChiaChing-Yen]

I encountered the same issue with @Ankur-singh, but I was able to resolve it by following @koichirokato's suggestion. No modifications were made to the roslibpy package.

Given that the solution worked, we can consider closing this issue.