Set up basic infrastructure for running a CLI smoke test

[Ryanf55]

Create a ROS2 package that can run a smoke test to ensure the DDS functionality in ardupilot is working as intended.

• Can be build with colcon build
• Can be tested with colcon test
• A failure to receive any messages results in failure
• A failure to receive messages within the expected rate results in failure
• A failure to receive the Time topic with the time close to epoch() results in failure
• A failure for the node to start results in failure

References:
https://github.com/ros2/launch_ros/pull/263/files#diff-9d860a3041f103f8e08aef7ce1db4364a4a7048ee6afaadd3c4e820647786e45

https://github.com/GitRepJo/ros2_cpp_test_example/blob/main/test/sub_pub_launch_testing.py

ros2/launch_ros#272

[srmainwaring]

Basic CLI smoke tests will probably go into the main ArduPilot repo. Development is on this branch: https://github.com/srmainwaring/ardupilot/tree/wip/ros2-pkg-cmake-v2.

Status

• A PoC testing the time message is published is running on the docker image https://github.com/ArduPilot/ardupilot_dev_docker/blob/ros/docker/Dockerfile_dev-ros

Items to resolve

ROS testing framework

There are multiple packages for testing launch with varying degrees of usage in ROS Humble and integration with colcon.

• launch
• launch_testing
• launch_pytest
• launch_ros
• launch_testing_ros
• ros2launch

Some guidance here: https://answers.ros.org/question/325167/difference-between-launch-and-launch_ros/, but examples and documentation are sparse.

Process clean up

• Ensure processes clean up on test exit (both success and failure). e.g. socat.

[Ryanf55]

Closed by #23429