Comment 0 for bug 1675571

Regresion from Bug #1657940.

When provisioning with multiple eth0 addresses, /etc/resolv.conf is empty:

Consider:
root@tester:~# cat /etc/network/interfaces.d/50-cloud-init.cfg
# This file is generated from information provided by
# the datasource. Changes to it will not persist across an instance.
# To disable cloud-init's network configuration capabilities, write a file
# /etc/cloud/cloud.cfg.d/99-disable-network-config.cfg with the following:
# network: {config: disabled}
auto lo
iface lo inet loopback

auto eth0
iface eth0 inet static
    address 138.197.98.102
    dns-nameservers 8.8.8.8 8.8.4.4
    gateway 138.197.96.1
    netmask 255.255.240.0

# control-alias eth0
iface eth0 inet static
    address 10.17.0.11
    netmask 255.255.0.0

Which then yields an empty /etc/resolv.conf:
root@tester:/run/resolvconf# cat interface/eth0.inet

root@tester:/run/resolvconf# cd /
# Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
# DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN

The problem is that resolvconfg does pattern matching for eth*.inet. The second definition of eth0 has no nameserver and therefore overrides the definition.