We need to open up the ipip protocol, which wasn't previously enabled.
Future work could construct the firewall rules in a common library,
and then adapt them to the various clouds.
Supporting IPv6 values where they can be set by the user, and ensuring
that IPv4 and IPv6 firewall rules are split because on GCP they cannot
be in the same rule.
We don't call klog.InitFlags yet, because that will cause a flag
redefinition error until we get everyone to stop using glog. That
will happen when we update to k8s 1.13.
We move everything to the models. We feature-flag it, because we
probably want to change the names etc, and we aren't going to be able to
offer smooth upgrades until that is done.