Comment 8 for bug 1524452

It's definitely not the fix we want. Here's what's happening (after discussing with smoser).
Each of the physical devices are brough up via ifup, and all semephor on /run/networking/ looking for ifup.eth0, ifup.eth1 and ifup.eth1:1.

The first two files are written when /etc/init/network-interface.conf job is run, called via udev device add (and spawned via the upstart-udev-bridge).

The alias interface won't come up until /etc/init/networking.conf job is run, which is blocked until local-filesystem is emitted. That signal isn't emitted until the semephore (/etc/network/if-up.d/upstart, which writes and emits the signal) is released. The semephor won't be released until all interfaces are up (eth1:1 is the only one not up yet) but of course it *wont* be up until ifup -a is called inside networking.conf.

This is the blocker/race.

I'd like to play with some way of allowing /etc/init/networking.conf to run after local-filesystem, but not have the static-network-up signal be emitted until ifup -a has completed.

I'll go take a look at bridge-utils and vlan.