skuber-to-json.scala

import $ivy.`io.skuber::skuber:2.0.5` 

import skuber._
import skuber.json.format._

val nginxSelector = Map("app" -> "nginx")
val nginxService = Service("nginx").withSelector(nginxSelector).exposeOnNodePort(30001 -> 80)

import akka.actor.ActorSystem
import akka.stream.ActorMaterializer

implicit val system = ActorSystem()
implicit val materializer = ActorMaterializer()
implicit val dispatcher = system.dispatcher

import akka.http.scaladsl.marshalling.Marshal
import akka.http.scaladsl.model.RequestEntity
import akka.util.ByteString
import skuber.json.PlayJsonSupportForAkkaHttp._

Marshal(nginxService)
  .to[RequestEntity]
  .map(_.dataBytes.runFold(ByteString.empty)(_ ++ _).map(_.utf8String))
  // or .map(_.toStrict(3.second).map(_.data.utf8String))
  .flatten
  .foreach(println)