[systemd-devel] [RFC] Preset Files

[Lennart Poettering]

On Wed, 06.07.11 09:33, Ludwig Nussel (ludwig.nussel at suse.de) wrote:

> 
> Lennart Poettering wrote:
> > <snip>
> > disable avahi-daemon.service
> > enable cups.service
> > disable *
> > </snip>
> 
> I suppose evaluation stops as soon as an entry matches. So as Distro
> we could have e.g 99-default "disable *" as default policy.

Correct.

> > - The RPM post macro would always call "systemctl preset" for the units
> >   passed, and never anything else.
> 
> What happens if the preset lists the service as enabled but the admin
> has disabled it manually? Will a package or distro upgrade re-enable
> the service? I suppose systemd needs to store somehere whether a
> preset was already applied for each service.

No, we'd consult the preset only on initial package installs. On
upgrades we'd not change enablement status.

> > - The reason why we'd implement "enable-by-default" instead of
> >   "disable-by-default" if no preset file is around is simply the idea
> >   that having to install stuff that is not needed is already a failure
> >   in itself, and ideally people who want to disable a service would just
> >   "rpm -e" it.
> 
> That's not quite the case, think of e.g. openssh where you may want
> the client but not the server¹ or mysqld which is used by kde per
> user or avahi where you may want avahi-daemon but not avahi-dnsconfd
> :-) However, that ok as long as we can put a "disable *" by default
> somewhere.

I think many distros split up avahi, mysql and openssh to deal with
this, an I think that's the right approach.

Lennart

-- 
Lennart Poettering - Red Hat, Inc.