Akka HTTP not allowing incoming connections from remote hosts on macOS

Question

I wanted to try out the following small example:

object Webserver {
  def main(args: Array[String]) {

    implicit val system = ActorSystem("my-system")
    implicit val materializer = ActorMaterializer()
    // needed for the future flatMap/onComplete in the end
    implicit val executionContext = system.dispatcher

    val route =
      path("hello") {
        get {
          redirect(Uri("https://google.com"), StatusCodes.PermanentRedirect)
        }
      }

    val bindingFuture = Http().bindAndHandle(route, "localhost", 8080)

    println(s"Server online at http://localhost:8080/\nPress RETURN to stop...")
    StdIn.readLine() // let it run until user presses return
    bindingFuture
      .flatMap(_.unbind()) // trigger unbinding from the port
      .onComplete(_ => system.terminate()) // and shutdown when done
  }
}

This works perfectly when accessing from the same host on macOS. However, when I am accessing the host remotely, I can't access the akka webserver.

I have checked my Firewall options and I verified that the program java allows incoming connections.

One more suspicious thing: When I run python -m SimpleHTTPServer 8080 , I get the following window:

I don't get this window when starting my akka application. Do I have to implement custom logic to ask for permission or something?

Answer 1

To enable remote access to your server, you need to bind your server to the external interface. To simply bind to all interfaces, you can set the host/IP to 0.0.0.0 , like:

Http().bindAndHandle(route, "0.0.0.0", 8080)