Example Kubernetes PetSet manifest for an etcd PetSet.

PetSets are still very early types in Kubernetes, but we can get etcd up and running with one, with a few particulars.

Of note:

• We must use the full DNS path for the peer URL, because the peer URL must
  • be resolvable before the associated Service discovers this Pod (chicken-and-egg problem)
  • be resolvable externally
  • match the advertised name with the initial cluster
  • this probably isn't necessary if you use the Discovery URL method.
• We can't assign a clusterIP to the Service because if we do, the PetSet unit names (e.g. etcd-0.etcd.default.svc.cluster.local) do not get created, though the service does.
• We can't create a separate service for clients with a clusterIP because something apparently gets confused or crossed, and the PetSet unit names don't get defined, either.