Description of problem:

The avahi daemon is being started on people's systems, even when explicitly disabled in every init setting, by systemd.

This appears to be due to a change in behaviour of systemd compared to the old init system.

With the previous init system, libvirt was able to register a callback with the avahi client library, so that _if_ avahi was ever started then libvirt would register with it automatically.  This would in no way cause avahi to be started for libvirt.  Libvirt doesn't need it.

Systemd seems to be getting this wrong, and is instead starting avahi anyway.

This is *very* not good for people trying to lock down or otherwise secure their systems. :(

This is the start of the email thread where the problem first surfaced in F14:

  http://lists.fedoraproject.org/pipermail/test/2010-September/093350.html

Information from one of the libvirt developers, on why the interaction seems to be systemd doing things wrong/differently compared to the previous system:

  http://lists.fedoraproject.org/pipermail/test/2010-September/093396.html


Version-Release number of selected component (if applicable):

  systemd-9-3.fc14.x86_64.rpm

How reproducible:

 Unsure.  I'm not the original bug reporter, though it seemed pretty consistent from Tim's email.


Steps to Reproduce:
1.  Start the libvirt daemon.
2.  The avahi-daemon is started, even when not enabled in the init levels. (this is the bug)