Custom Listener

You can implement your own listener builder. Write an actor class, make it available on the class path, and set the config to the fully qualified class name.

// Domain Object
{
  domain-name: "example.com"
  listeners: [
    {id: my_listener, builder: "com.example.MyListenerBuilder"}
  ]

  listener-config {

    // id used in the listeners list
    my_listener {

      // The settings in this object will be provided to the listener builder
      ???: ...
    }
  }
}

The class to be loaded must implement shield.actors.config.listener.ListenerBuilder, and have a constructor that takes two parameters:

  • id: String - The id of the listener to be built
  • settings: shield.config.DomainSettings - The domain settings, which provides access to the settings for the listener to be built
trait ListenerBuilder extends Actor {
  val settings = Settings(context.system)
}

To register the listener with Shield, the builder actor must send a shield.actors.config.ConfigWatcherMsgs.ListenerUpdated message to its parent actor. It can do this multiple times if it wants to change actors used by Shield. If you’re swapping actors, you should wait for Spray’s global request timeout to elapse before killing the old listener actor, to allow any in flight requests to be drained.

case class ListenerUpdated(id: String, listener: ActorRef)

The actor that gets registered as a listener will receive shield.actors.RequestProcessorCompleted messages. It is then free to whatever it wants.

// Incoming message
case class RequestProcessorCompleted(
  completion: ResponseCompleted,
  overallTiming: Long,
  middlewareTiming: Map[String, Long]
)

case class ResponseCompleted(
  request: HttpRequest,
  details: ResponseDetails
)

case class ResponseDetails(
  serviceLocation: ServiceLocation,
  serviceName: String,
  template: EndpointTemplate,
  explicitCacheParams: Option[Set[Param]],
  response: HttpResponse
)

Config Topic