Change config key used for Cluster Bootstrap Discovery Method

[TimMoore]

This currently sets the akka.discovery.method config setting to kubernetes-api or marathon-api, depending on the deployment target:

reactive-cli/cli/shared/src/main/scala/com/lightbend/rp/reactivecli/runtime/kubernetes/PodTemplate.scala

Lines 74 to 92 in a4b0a24

	private[kubernetes] def akkaClusterEnvs(modules: Set[String], namespace: Option[String], serviceResourceName: String, noOfReplicas: Int, akkaClusterBootstrapSystemName: Option[String], akkaClusterJoinExisting: Boolean): Map[String, EnvironmentVariable] =
	if (!modules.contains(Module.AkkaClusterBootstrapping))
	Map.empty
	else
	Map(
	"RP_JAVA_OPTS" -> LiteralEnvironmentVariable(
	Seq(
	s"-Dakka.discovery.method=kubernetes-api",
	s"-Dakka.management.cluster.bootstrap.contact-point-discovery.effective-name=$serviceResourceName",
	s"-Dakka.management.cluster.bootstrap.contact-point-discovery.required-contact-point-nr=$noOfReplicas",
	akkaClusterBootstrapSystemName.fold("-Dakka.discovery.kubernetes-api.pod-label-selector=appName=%s")(systemName => s"-Dakka.discovery.kubernetes-api.pod-label-selector=actorSystemName=$systemName"),
	s"${if (akkaClusterJoinExisting) "-Dakka.management.cluster.bootstrap.form-new-cluster=false" else ""}")
	.filter(_.nonEmpty)
	.mkString(" ")),
	"RP_DYN_JAVA_OPTS" -> LiteralEnvironmentVariable(
	Seq(
	"-Dakka.discovery.kubernetes-api.pod-namespace=$RP_NAMESPACE")
	.filter(_.nonEmpty)
	.mkString(" ")))

reactive-cli/cli/shared/src/main/scala/com/lightbend/rp/reactivecli/runtime/marathon/RpEnvironmentVariables.scala

Lines 54 to 66 in 08addd9

	private def akkaClusterEnvs(modules: Set[String], namespace: Option[String], serviceResourceName: String, noOfReplicas: Int, akkaClusterBootstrapSystemName: Option[String], akkaClusterJoinExisting: Boolean): Map[String, String] =
	if (!modules.contains(Module.AkkaClusterBootstrapping))
	Map.empty
	else
	Map(
	"RP_JAVA_OPTS" -> Seq(
	s"-Dakka.discovery.method=marathon-api",
	s"-Dakka.management.cluster.bootstrap.contact-point-discovery.effective-name=$serviceResourceName",
	s"-Dakka.management.cluster.bootstrap.contact-point-discovery.required-contact-point-nr=$noOfReplicas",
	akkaClusterBootstrapSystemName.fold("-Dakka.discovery.marathon-api.app-label-query=APP_NAME==%s")(systemName => s"-Dakka.discovery.marathon-api.app-label-query=ACTOR_SYSTEM_NAME==$systemName"),
	s"${if (akkaClusterJoinExisting) "-Dakka.management.cluster.bootstrap.form-new-cluster=false" else ""}")
	.filter(_.nonEmpty)
	.mkString(" "))

These globally sets the default discovery method to an implementation that is only appropriate to use for Cluster Bootstrap and not for inter-service discovery. This will cause problems for Akka gRPC users, and in the future, all Lagom users.

This should be updated to set akka.management.cluster.bootstrap.contact-point-discovery.discovery-method instead of akka.discovery.method, as described in akka/akka-management#316.