Add process_name parameter in system to change fluentd's process name

[repeatedly]

Like https://github.com/cubicdaiya/fluent-plugin-setproctitle plugin.
Set process_name,

<system>
  process_name foo
</system>

ps result is below.

% ps aux | grep foo
repeatedly      45673   0.4  0.2  2523252  38620 s001  S+    7:04AM   0:00.44 worker:foo
repeatedly      45647   0.0  0.1  2481260  23700 s001  S+    7:04AM   0:00.40 supervisor:foo

[tagomoris]

👍

[sonots]

I can imagine that someone requests that he wants to set entire proctitle. How about providing supervisor_process_name, and worker_process_name options?

Also, should note how it behaves on Windows (maybe, on docs). How does it behave?

[cubicdaiya]

👍

[repeatedly]

@sonots

I can imagine that someone requests that he wants to set entire proctitle.

Hmm... any situation? I sometimes received this feature request for better fluentd process management because current process name is bit messy.
Current patch identifies supervisor and worker using a prefix. Could you show me the good example?

[sonots]

It just depends on users' preference. He may want to name as fluentd worker rather than worker:fluentd.

[repeatedly]

If it is may, I think we don't need to support two parameters for now.

[repeatedly]

My first implementation was fluentd-supervisor and fluentd-worker.
I'm not sure which is better.

[repeatedly]

No against for worker and supervisor prefix, I will merge it.