Re: systemd as external dependency

[Bastien Nocera <hadess hadess net>]

On Wed, 2011-05-18 at 14:46 -0500, Federico Mena Quintero wrote:
> On Wed, 2011-05-18 at 14:09 +0200, Lennart Poettering wrote:
> 
> [setting the hostname and other little interfaces]
> > In the long run I expect the following additional interfaces used by
> > GNOME or one of its components:
> > 
> > - I am working on two more mechanisms generalizing control of the system
> >   locale and system clock/timezone for use in the control center and by
> >   other UIs.
> 
> A while ago, Rodrigo Moya had a lovely idea.  Back then we were
> discussing the problem of distros having different mechanism for "stupid
> little tasks which should be uncontroversial", like the hostname,
> timezone, etc.
> 
> The plan was to introduce D-Bus interfaces to frob these things, and
> then to cunningly provide an AdminKit with implementations of the
> corresponding services.  Distros would realize, "oh, hey, we can use
> this pre-made code instead of maintaining our own hacks - let's do
> that".  And then AdminKit would be a de-facto standard interface and
> unicorns would excrete rainbows.  Recalcitrant systems would be de-facto
> forced to implement those D-Bus interfaces however they please.
> 
> Your idea, of course, is the same - except that it puts the services in
> systemd (maybe not systemd itself, but the systemd package).  You need
> somewhere to put them, after all.
> 
> There are *probably* hit-and-run services like "set the hostname" where
> D-Bus activation could launch a tiny helper process that changes the
> hostname and emits a signal, and dies quickly.  These present no
> problem, except for how to ship them.
> 
> There are *probably* services that need to be running constantly, but I
> can't think of one right now.  Those need a daemon.  I'm kind of unhappy
> of the proliferation of daemons that we had at one point -
> gnome-session, the user's D-Bus daemon, gnome-settings-daemon, etc.
> Maybe if we had One Standard Way of loading service-y things into a
> central daemon, we could save a little memory and context switches?  Is
> this even worthwhile?  (If one crashes, it would make things much
> worse...).
> 
> Maybe putting your services in an AdminKit would make things more
> palatable to unenlightened^H^H^H^Htraditionalist systems that don't want
> to use systemd just yet?
> 
> (Note: I don't care much where the services are shipped.  But putting
> them in neutral ground may be better/easier in the medium term.)

Which is why I've asked Lennart to add a flag to systemd's configure to
install only the little servicey bits, for Linux distros, and the docs
would serve as basis for implementation of other OSes.

This would solve the problem of distributions that don't want to use
systemd as the init system, and the Debian/FreeBSD probleme where just
the filesystem layout is the same as a Linux distribution.