Minimal akka http proxy

Proxy.scala

package akkahttptest

import akka.actor.ActorSystem
import akka.http.Http
import akka.stream.FlowMaterializer
import akka.http.server._
import akka.http.marshalling.PredefinedToResponseMarshallers._
import akka.stream.scaladsl.{HeadSink, Source}

object Proxy extends App {

  implicit val system = ActorSystem("Proxy")

  implicit val materializer = FlowMaterializer()

  implicit val ec = system.dispatcher

  val proxy: Route = Route { context =>
    val request = context.request
    println("Opening connection to " + request.uri.authority.host.address)
    val flow = Http(system).outgoingConnection(request.uri.authority.host.address, 80).flow
    Source.single(context.request)
      .via(flow)
      .runWith(HeadSink())
      .flatMap(r => context.complete(r))
  }

  val binding = Http(system).bind(interface = "localhost", port = 1080)

  binding.startHandlingWith(proxy)
}