[ros2doctor] Add QoS compatibility check and report

[audrow]

Here is an example of what the check looks like if an incompatibility error is detected;

/root/ros2_ws/build/ros2doctor/ros2doctor/api/qos_compatibility.py: 49: UserWarning: ERROR: QOS compatibility error found on topic '/my_chatter'. Use `ros2 doctor --report` for more details.

Here is what a report looks like with two pub/sub pairs, one compatible and one incompatible:

   QOS COMPATIBILITY LIST
topic [type]            : /chatter [std_msgs/msg/String]
publisher node          : talker
subscriber node         : listener
compatibility status    : OK
topic [type]            : /my_chatter [std_msgs/msg/String]
publisher node          : mynode
subscriber node         : mynode
compatibility status    : ERROR: Best effort publisher and reliable subscription;

The messages for warnings are similar.

Here is the report if there are no publisher/subscription pairs:

   QOS COMPATIBILITY LIST
compatibility status    : No publisher/subscriber pairs found

I haven't written any tests for this yet and would be happy for suggestions on how to do so.

[fujitatomoya]

i am good to go with this, test would be ideal.

[jacobperron]

Looks good! I've left some comments/suggestions below.

I haven't tried it out yet. I agree that it would be good to add a test.

[audrow]

The new check error output is as follows:

/root/ros2_ws/build/ros2doctor/ros2doctor/api/qos_compatibility.py: 49: UserWarning: ERROR: QoS compatibility error found on topic '/chatter': Best effort publisher and reliable subscription;

Warnings are displayed similarly.

[jacobperron]

LGTM pending CI

[fujitatomoya]

lgtm with a couple of nitpicks.

[fujitatomoya]

CI:

• Linux
• Linux-aarch64
• macOS
• Windows

[audrow]

Another CI run:

• Linux
• Linux-aarch64
• macOS
• Windows

[audrow]

• Linux
• Linux-aarch64
• macOS
• Windows

[audrow]

I weakened the tests because I was still getting the errors on CI with repeated retries. I'm not sure why several ROS2 doctor checks fail on CI, but not on my local machine.

• Linux
• Linux-aarch64
• macOS
• Windows

[RDaneelOlivav]

Is this feture in the debians already? Because I've run this in my local isntalation og Galactic and it just doesnt generate this Compatibility info. Any ideas?

[fujitatomoya]

I think that this is merged only to master (Humble), so galactic does not support this feature.

[jacobperron]

That's correct, this is only available in Rolling (to be Humble). However, I think the nature of the change makes it backportable if someone would like to open up a backport PR to Galactic (and maybe Foxy).