Comment 4 for bug 1315501

config drive != injection.

if nova "injected" the file (placed it in /etc/network/interfaces) then there isn't anything I can do. Essentially, "nova broke your image".

If nova placed the /etc/network/interfaces file on to a config drive, and cloud-init read it and wrote /etc/network/interfaces then cloud-init was at fault.

Both paths are possible. I generally believe the first one to be simply wrong and don't care if it is broken, the answer is "don't inject files into an image".

We'll fix the second path in cloud-init.