Network configuration future

[Dan Williams]

On Mon, 2012-09-03 at 09:20 +0200, Olaf Kirch wrote:
> On Thursday 30 August 2012 08:55:02 Bill Nottingham wrote:
> > > The systemd people do have some ideas they've already been kicking around
> > > for this already... have you seen it?
> > 
> > To be clear, I'm not really convinced yet that this is something we need...
> > there is a lot of legacy admin overhead and infrastructure that is highly
> > resistant to change here.
> 
> Agreed. On the other hand, with systemd comes a lot of change anyway.
> And obviously, something like wicked doesn't have to be completely disruptive.
> The idea is to still have ifup/ifdown scripts for those who have been
> using them, and have written their scripts around those. Or to be able
> to parse the old ifcfg-* files for backward compatibility.

The problem with integrating network management into systemd in some
form is that system only wants to handle the "simple" use-cases.  Mainly
because it's intended to be a lightweight part of the boot process.

But when you start handling any "simple" networking, you'll eventually
start handling more complex networking too, because users will request
it.  And then at some point, you're duplicating all the code that a more
complex network management daemon is already doing, and that makes
things more confusing for everyone.

Is this interface managed by systemd?  Or is this interface managed by
NM/something-else?  Or is this interface manually managed?  Should you
even have to make this choice?  What mediates the routing table and the
DNS entries if you have systemd managing some interfaces, NM some other
interfaces, and manually managed interfaces too?  Another daemon?  Yay!
Piles of daemons!  And since this is Linux, everyone wants to use each
thing in isolation from the others, so you can't depend on anything else
being on the system.

Talking about low-level networking in systemd or whatever
flavor-of-the-year initsystem there happens to be necessarily brings up
questions like this.  I'm not sure the right place for this sort of
thing is in the init system.  Instead, we should be creating a
lightweight-enough network management daemon that could be included on
these resource-constrained systems along with systemd to do that.  Which
is also something we're working towards with NetworkManager.  It's
actually been possible for a long time to build/run NM without any of
[wpa-supplicant, ppp, ConsoleKit, PolicyKit, bluez, etc] if you want a
stripped-down system.

Dan


> Olaf
> -- 
> Neo didn't bring down the Matrix. SOA did. (soafacts.com)
> --------------------------------------------
> Olaf Kirch - Director SUSE Linux Enterprise; R&D (okir at suse.com)
> SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany
> GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer, HRB 16746 (AG Nürnberg)