More verbose exit logging

[tilgovi]

• Add logging at error level for abnormal worker exit codes.
• Make arbiter shutdown log at error level for abnormal exits.

[nakulcg]

I installed gunicorn from this branch, but I dont see below in logs, note: I am running gunicorn with DEBUG log level

'Worker (pid:%s) exited with code %s'

but I do see

Out of memory: Kill process 14666 (gunicorn) score 319 or sacrifice child

in dmesg in debian buster container

[tilgovi]

@benoitc any changes you still want here? I responded to your earlier feedback.

[kosciCZ]

Bump, I'd really like to see this merged.

[tilgovi]

@benoitc can you please take another look at this one?

[harto]

Hello, this would be useful for us too :)

[sp1rs]

@tilgovi Should it pass the exitcode to child_exit function? This will give client more flexibility to play around. In my case I would like to log the exitcode as well as based on certain logic also predict if it is OOM or not. Also I like the proposal to add the exit code to worker.