We add the hosts plugin to CoreDNS, and we populate a ConfigMap from
kops-controller (when in gossip mode).
This enables resolution of the internal apiserver DNS name from Pods,
even when gossip mode (k8s.local) is in use. This should fix the
failing e2e tests which are assuming that the name in the JWT token is
resolvable from inside the cluster.
This is also a possible step towards a simpler gossip mode, now that
we have a central controller.
The client-go signature for most methods adds a context.Context
object, and also makes Options mandatory. Feed through a
context.Context through many of our methods (but use context.TODO to
stop it getting totally out of hand!)
justinsb