Set rmw log severity

[christophebedard]

Closes #915

This makes rcl call rmw_set_log_severity if the default level is set, e.g. with --ros-args --log-level debug.

Signed-off-by: Christophe Bedard [email protected]

[christophebedard]

Not sure if this is the best place to put it, but it feels like the simplest solution, and it's right next to rcutils_logging_set_default_logger_level so it does make sense.

[christophebedard]

I've also added a test: 90ed0db

[clalancette]

What you are doing here makes a certain sense; if we are changing the default logging level, we should change it everywhere.

On the other hand, I'm not sure what semantic we really want --log-level to have. As it stands right now, the semantic is more-or-less "core ROS 2 code". If we add this code in, it becomes "core ROS 2 code + RMW backend code". I'm not entirely sure that's what we want to do.

I think this would be helped by spelling out what the log-levels mean in a more rigorous way, probably as part of ros2/design#314 .

[christophebedard]

I understand. The fact that rmw implementations don't support the "unset" logging level/state definitely highlights this.

Are there any plans to tackle that soon-ish after Galactic? I can't commit to doing ros2/design#314, but I can probably help, and I can certainly implement whatever is in the design document for this.

[clalancette]

Are there any plans to tackle that soon-ish after Galactic?

The honest answer is that I don't know right now. We've been concentrating on Galactic, so we don't have a roadmap for H-Turtle yet. I do hope it is something that the ROS 2 community gets to for H-Turtle, as I think it is important.

[christophebedard]

Got it. I'll see what I can do (in a few weeks) then.

I'll leave this draft here for now.

[Yadunund]

I'd be interested in resurrecting the effort here, especially to address ros2/rmw_zenoh#423.

I'm in favor of having --log-level define the logging level at the RMW level as well since a lot of users are familiar with this arg and in fact, other tier-1 middlewares which rely on RCUTILS_LOG_XX macros seem to honor the --log-level arg. However in rmw_zenoh, we have custom logging macros and having rcl call rmw_set_log_severity would be a convenient way of changing the logging level of the custom logger.