Change default QoSProfile for pub

[gonzodepedro]

Signed-off-by: Gonzalo de Pedro gonzalo@depedro.com.ar

[gonzodepedro]

This PR uses ACTION_STATUS_DEFAULT which sets "Reliable" reliability and "Transient-local" durability.

[jacobperron]

It seems a bit awkward to choose the "action status" preset. How about we don't set a default QoS profile for the --qos-profile CLI arg? We can instead use some custom QoS profile, unless the user explicitly passes the --qos-profile option.

[fujitatomoya]

just a quick question, is there any requirement or actual problems to reset the default?

[jacobperron]

just a quick question, is there any requirement or actual problems to reset the default?

While addressing #594 for ros2 topic echo, we also reviewed what QoS was being used for ros2 topic pub. Most users won't notice QoS matching issues with the "system default" QoS profile, though it does not guarantee that QoS will always match since it is system dependent. Also, chances are the default durability setting is volatile, which won't match transient_local subscriptions. By making ros2 topic pub reliable and transient_local by default, we provide the most flexible QoS.

As an aside, "system default" was chosen arbitrarily: #245

@fujitatomoya Does that answer your question?

[fujitatomoya]

@jacobperron

it does. thanks for the explanation.

[ivanpauno]

LGTM, I have a few minor comments

[ivanpauno]

LGTM with green CI.

I would recommend using --packages-up-to ros2topic for building and --packages-select ros2topic for testing.

[gonzodepedro]

CI:

• Linux
• Linux-aarch64
• macOS
• Windows

[jacobperron]

LGTM