Instead of endpoints being a flat list, it is now a list of "subsets"
where each is a struct of {Addresses, Ports}. To generate the list of
endpoints you need to take union of the Cartesian products of the
subsets. This is compact in the vast majority of cases, yet still
represents named ports and corner cases (e.g. each pod has a different
port number).
This also stores subsets in a deterministic order (sorted by hash) to
avoid spurious updates and comparison problems.
This is a fully compatible change - old objects and clients will
keepworking as long as they don't need the new functionality.
This is the prep for multi-port Services, which will add API to produce
endpoints in this new structure.
This allows a container to run within the same networking namespace as
the host. This will be locked down by default using a flag on the master
and nodes (similar to how privileged is handled today).
In v1b1 and v1b2 we choose the "first defined port" if you do not specify a
ContainerPort. I am proposing that v1b3 just assume the ContainerPort is the
same as the service port unless explicitly provided. This leaves named ports
for now, but that is under discussion on its own.
This is strictly compatible, though to implement this we have to leave the
internal objects with the looser behavior until v1b[12] die. This also adds a
link dependency so that when we DO kill v1b[12] the endpoints controller will
blow up, prompting a fix.
