Comment 8 for bug 2028023

systemd-networkd.service (and .socket) seems to be enabled by default on Ubuntu server images through livecd-rootfs: https://git.launchpad.net/ubuntu/+source/livecd-rootfs/tree/live-build/ubuntu-server/includes.chroot.ubuntu-server-minimal/etc/systemd/system

So in order to keep networkd disable on such images, we'd probably need to use something like "systemctl mask systemd-networkd.service".