Since commit 0ce4b6b412
NetworkManager-wait-online.service quits immediately if there is no link yet.
Fix it by removing the '-x' option.
But if we do just that, NM-w-o would add a useless 30 seconds delay in the
case when NM is not running at all.
Solve this by adding a Requisite= dependency on NM.
https://bugzilla.redhat.com/show_bug.cgi?id=710502
1) Don't require NM, but run after it. This allows this service
to be installed without bringing up NetworkManager. Add -x so that
it exits if NM isn't running.
2) Install as a want of network.target, instead of multi-user.target.
This allows us to skip it if nothing requires network.target or the
legacy $network SysV capability.
This pulls in network.target from NetworkManager.service (and not the
other way round), as suggested and agreed on on the systemd ML:
http://lists.freedesktop.org/archives/systemd-devel/2011-March/001692.html
This also introduces an auxiliary service
NetworkManager-wait-online.service that can be used to order a unit
after the point where the network is available. When this is enabled
with "systemd enable NetworkManager-wait-online.service" the unit
network.target will be delayed until the network is up, which is
suitable for synchronizing NFS mounts and similar to it.
https://bugzilla.redhat.com/show_bug.cgi?id=692008