Akka Http Client Set Cookie on a HttpRequest - scala

Question

I am trying to make a GET request to a REST web service using Akka Http Client.
I am not able to figure out how do I set a cookie on the request before I make the GET.
I searched the web and I found ways to read the cookie on the server side. but I could not find anything which showed me how to set the cookie on the client side request.
Based on my own research I tried the following approach to set a cookie on http request
import akka.actor.ActorSystem
import akka.http.scaladsl.Http
import akka.http.scaladsl.model._
import akka.http.scaladsl.unmarshalling.Unmarshal
import akka.stream.scaladsl.{Sink, Source}
import akka.http.scaladsl.marshallers.sprayjson.SprayJsonSupport
import akka.http.scaladsl.model.headers.HttpCookie
import akka.stream.ActorMaterializer
import spray.json._
import scala.util.{Failure, Success}
case class Post(postId: Int, id: Int, name: String, email: String, body: String)
trait JsonSupport extends SprayJsonSupport with DefaultJsonProtocol {
implicit val postFormat = jsonFormat5(Post.apply)
}
object AkkaHttpClient extends JsonSupport{
def main(args: Array[String]) : Unit = {
val cookie = headers.`Set-Cookie`(HttpCookie(name="foo", value="bar"))
implicit val system = ActorSystem("my-Actor")
implicit val actorMaterializer = ActorMaterializer()
implicit val executionContext = system.dispatcher
val mycookie = HttpCookie(name="foo", value="bar")
val httpClient = Http().outgoingConnection(host = "jsonplaceholder.typicode.com")
val request = HttpRequest(uri = Uri("/comments"), headers = List(cookie))
val flow = Source.single(request)
.via(httpClient)
.mapAsync(1)(r => Unmarshal(r.entity).to[List[Post]])
.runWith(Sink.head)
flow.andThen {
case Success(list) => println(s"request succeded ${list.size}")
case Failure(_) => println("request failed")
}.andThen {
case _ => system.terminate()
}
}
}
But this gives an error
[WARN] [08/05/2016 10:50:11.134] [my-Actor-akka.actor.default-dispatcher-3] [akka.actor.ActorSystemImpl(my-Actor)]
HTTP header 'Set-Cookie: foo=bar' is not allowed in requests

Answer 1

The idiomatic way to construct any header for an akka-http client is by
using akka.http.scaladsl.model.headers.
In your case it would be
val cookieHeader = akka.http.scaladsl.model.headers.Cookie("name","value")
HttpRequest(uri = Uri("/comments"), headers = List(cookieHeader, ...))

Answer 2

The outgoing header must be 'Cookie' not 'Set-Cookie':
val cookie = HttpCookiePair("foo", "bar")
val headers: immutable.Seq[HttpHeader] = if (cookies.isEmpty) immutable.Seq.empty else immutable.Seq(Cookie(cookies))
val request = HttpRequest(uri = uri).withHeadersAndEntity(headers, HttpEntity(msg))