What is elegant way to do configuration on server app

[Marko Rauhamaa]

Chris Angelico <rosuav at gmail.com>:

> The number of cases where this matters is fairly low. Doing the reload
> asynchronously is generally sufficient.

Not sure. Not sure at all. Issues like this occupy a great part of my
office hours.

> And even if you have something that waits for the reload to finish,
> you'll usually fire-and-forget that command anyway.

The command

   systemctl reload xyz.service

is supposed to return when the service is happily running with the
updated its configuration.

Any failures should be reported with a nonzero exit code from
"systemctl".

> For maximum portability, most programs are going to want to continue
> to respond to SIGHUP, even if they do a systemd-triggered reload some
> other way.

I disagree. You can't just assume you can send a SIGHUP to a daemon for
the LOLs. You must first discover the trick in the documentation.

The default reaction to SIGHUP is to crash. A daemon (which has detached
from the controlling terminal) is within its rights to do just that.


Marko