[bug#62802] [PATCH 0/4] Add reload action to syslog service.

[Maxim Cournoyer]

Hello,

Ludovic Courtès <ludo@gnu.org> writes:

> Maxim Cournoyer <maxim.cournoyer@gmail.com> skribis:
>
>> Having the configuration live at a static location makes it possible to
>> hot-reload it.
>>
>> * gnu/services/base.scm (syslog.conf): New variable.
>> (syslog-etc, syslog-shepherd-service): New procedures.
>> (syslog-service-type): Rewrite using the above new variable and procedures,
>> extending etc-service-type with its configuration file.
>
> I’m really not a fan of static configuration file names: you can never
> be sure what config the service is using—compare this with the
> unambiguous ‘--config=/gnu/store/…example.conf’.

Right; although now if you aren't sure what is used you can 'reload' it,
eh :-).

> Unfortunately there’s often no other option if we want to support live
> reconfiguration—there’s only so much a signal can convey.
>
> So I guess it’s a “weak accept” from me, because live reload is useful.

OK!

> With the Shepherd in ‘master’, there’s a hook to change a service’s
> “running value” so it should be possible to stop the previous process,
> start a new one, and update the service’s running value (which is not
> equivalent to SIGHUP, but maybe good enough for some cases).

Wouldn't that be equivalent to restarting the service?  I wasn't aware
of the new hook facility, I'll have to read on it, thanks!

> A simpler approach might be run the service in a container with
> /gnu/store/…conf mapped to a fixed location, and somehow update that
> mapping as we go.  Food for thought!

Interesting idea... although it'd only be compatible with Linux and I
dislike writing special cases in services (or anywhere if I can help
it).

-- 
Thanks,
Maxim