!clu #15042 useRole restriction on local node is now respected

This is an API breaking change if someone implemented their own Routers.
The change is required because the router must know if the local routees
should be started or not so it has to check the roles of the cluster
member (the local one). We could delay this decision of starting local
routees, but that would allow messages to be dead-letter-ed (bad).

akka-cluster/src/main/scala/akka/cluster/routing/ClusterRouterConfig.scala

@@ -3,43 +3,31 @@
  */
 package akka.cluster.routing
 
-import scala.collection.immutable
-import akka.routing.RouterConfig
-import akka.routing.Router
-import akka.actor.Props
-import akka.actor.ActorContext
-import akka.routing.Routee
 import java.util.concurrent.atomic.AtomicInteger
-import akka.actor.Address
-import akka.actor.ActorCell
-import akka.actor.Deploy
-import com.typesafe.config.ConfigFactory
-import akka.routing.ActorRefRoutee
-import akka.remote.RemoteScope
-import akka.actor.Actor
-import akka.actor.SupervisorStrategy
-import akka.routing.Resizer
-import akka.routing.RouterConfig
-import akka.routing.Pool
-import akka.routing.Group
-import akka.remote.routing.RemoteRouterConfig
-import akka.routing.RouterActor
+
+import akka.actor._
 import akka.cluster.Cluster
 import akka.cluster.ClusterEvent._
-import akka.actor.ActorRef
 import akka.cluster.Member
-import scala.annotation.tailrec
-import akka.actor.RootActorPath
 import akka.cluster.MemberStatus
-import akka.routing.ActorSelectionRoutee
-import akka.actor.ActorInitializationException
-import akka.routing.RouterPoolActor
-import akka.actor.ActorSystem
-import akka.actor.ActorSystem
-import akka.routing.RoutingLogic
-import akka.actor.RelativeActorPath
-import com.typesafe.config.Config
 import akka.japi.Util.immutableSeq
+import akka.remote.RemoteScope
+import akka.routing.ActorRefRoutee
+import akka.routing.ActorSelectionRoutee
+import akka.routing.Group
+import akka.routing.Pool
+import akka.routing.Resizer
+import akka.routing.Routee
+import akka.routing.Router
+import akka.routing.RouterActor
+import akka.routing.RouterConfig
+import akka.routing.RouterPoolActor
+import akka.routing.RoutingLogic
+import com.typesafe.config.Config
+import com.typesafe.config.ConfigFactory
+
+import scala.annotation.tailrec
+import scala.collection.immutable
 
 object ClusterRouterGroupSettings {
   def fromConfig(config: Config): ClusterRouterGroupSettings =
@@ -127,7 +115,8 @@ private[akka] trait ClusterRouterSettingsBase {
   def allowLocalRoutees: Boolean
   def useRole: Option[String]
 
-  if (totalInstances <= 0) throw new IllegalArgumentException("totalInstances of cluster router must be > 0")
+  require(useRole.isEmpty || useRole.get.nonEmpty, "useRole must be either None or non-empty Some wrapped role")
+  require(totalInstances > 0, "totalInstances of cluster router must be > 0")
 }
 
 /**
@@ -183,7 +172,14 @@ final case class ClusterRouterPool(local: Pool, settings: ClusterRouterPoolSetti
   /**
    * Initial number of routee instances
    */
-  override def nrOfInstances: Int = if (settings.allowLocalRoutees) settings.maxInstancesPerNode else 0
+  override def nrOfInstances(sys: ActorSystem): Int =
+    if (settings.allowLocalRoutees && settings.useRole.isDefined) {
+      if (Cluster(sys).selfRoles.contains(settings.useRole.get)) {
+        settings.maxInstancesPerNode
+      } else 0
+    } else if (settings.allowLocalRoutees && settings.useRole.isEmpty) {
+      settings.maxInstancesPerNode
+    } else 0
 
   override def resizer: Option[Resizer] = local.resizer
 
@@ -195,8 +191,8 @@ final case class ClusterRouterPool(local: Pool, settings: ClusterRouterPoolSetti
   override def supervisorStrategy: SupervisorStrategy = local.supervisorStrategy
 
   override def withFallback(other: RouterConfig): RouterConfig = other match {
-    case ClusterRouterPool(_: ClusterRouterPool, _) ⇒ throw new IllegalStateException(
-      "ClusterRouterPool is not allowed to wrap a ClusterRouterPool")
+    case ClusterRouterPool(_: ClusterRouterPool, _) ⇒
+      throw new IllegalStateException("ClusterRouterPool is not allowed to wrap a ClusterRouterPool")
     case ClusterRouterPool(otherLocal, _) ⇒
       copy(local = this.local.withFallback(otherLocal).asInstanceOf[Pool])
     case _ ⇒
@@ -321,6 +317,7 @@ private[akka] class ClusterRouterGroupActor(val settings: ClusterRouterGroupSett
     } else {
       // find the node with least routees
       val unusedNodes = currentNodes filterNot usedRouteePaths.contains
+
       if (unusedNodes.nonEmpty) {
         Some((unusedNodes.head, settings.routeesPaths.head))
       } else {
@@ -359,7 +356,7 @@ private[akka] trait ClusterRouterActor { this: RouterActor ⇒
   override def postStop(): Unit = cluster.unsubscribe(self)
 
   var nodes: immutable.SortedSet[Address] = {
-    import Member.addressOrdering
+    import akka.cluster.Member.addressOrdering
     cluster.readView.members.collect {
       case m if isAvailable(m) ⇒ m.address
     }
@@ -376,13 +373,12 @@ private[akka] trait ClusterRouterActor { this: RouterActor ⇒
   }
 
   def availableNodes: immutable.SortedSet[Address] = {
-    import Member.addressOrdering
-    val currentNodes = nodes
-    if (currentNodes.isEmpty && settings.allowLocalRoutees && satisfiesRole(cluster.selfRoles))
-      //use my own node, cluster information not updated yet
+    import akka.cluster.Member.addressOrdering
+    if (nodes.isEmpty && settings.allowLocalRoutees && satisfiesRole(cluster.selfRoles))
+      // use my own node, cluster information not updated yet
       immutable.SortedSet(cluster.selfAddress)
     else
-      currentNodes
+      nodes
   }
 
   /**
@@ -424,7 +420,7 @@ private[akka] trait ClusterRouterActor { this: RouterActor ⇒
 
   def clusterReceive: Receive = {
     case s: CurrentClusterState ⇒
-      import Member.addressOrdering
+      import akka.cluster.Member.addressOrdering
       nodes = s.members.collect { case m if isAvailable(m) ⇒ m.address }
       addRoutees()