WIP: ip per service

This is filled with cruft, but I wanted to float the idea.  It actually works.

Overview:  When a service object is created, allocate it an IP.  Broadcast that IP to all kube-proxies.  Each one will set up iptables rules to forward traffic for that IP:port to a random local port.  Clients connect to a stable ip:port but no more port collisions!
Turning my attention back to this topic.  I need to store information about the IP ranges that have been configured for portal IPs and a mapping of each service to an IP.

Storing the IP along with each service object seems reasonable to me - that's the thing that the kube-proxy is already watching.

I could store some new /registry/portalRange/* objects, each with a bitmap or something.  But how do those get created?  Is it kosher for apiserver to take a commandline flag and then manifest that into etcd?  Or should it assume that configuration already exists in etcd?  Do we have any other precedents for configuring the master?

I don't feel comfortable claiming to know what the plans are around the etcd schema, so I am asking :)