Spotlight cluster singleton proxy

gistfile1.scala

class MasterProxy extends Actor {
  // subscribe to LeaderChanged, re-subscribe when restart
  override def preStart(): Unit =
    Cluster(context.system).subscribe(self, classOf[LeaderChanged])
  override def postStop(): Unit =
    Cluster(context.system).unsubscribe(self)
 
  var leaderAddress: Option[Address] = None
 
  def receive = {
    case state: CurrentClusterState => leaderAddress = state.leader
    case LeaderChanged(leader)      => leaderAddress = leader
    case other                      => master foreach { _ forward other }
  }
 
  def master: Option[ActorRef] =
    leaderAddress map (a ⇒ context.actorFor(RootActorPath(a) /
      "user" / "singleton" / "master"))
}