This document provides an overview and introduction to Akka HTTP, a Scala library built on Akka Streams for HTTP-based applications. Some key points: - Akka HTTP uses Akka Streams to model HTTP requests and responses as streaming data flows. - It allows building both HTTP clients and servers by composing stream processing stages together. - Common directives and operations like routing, marshalling, validation, and testing are supported through a high-level API. - Examples demonstrate basic usage like creating a route that returns XML, running a server, and writing tests against routes.

1. AKKA HTTP
A.K.A. SPRAY 2.0
Présenté par Jean Detoeuf / @thebignet

2. JEAN DETOEUF
DÉVELOPPEUR
Passionné de nouvelles technologies
#jvm #docker #craftmanship #rpi #diy

3. AVERTISSEMENT
Je ne suis pas un expert en Scala
Soyez sympas ^^

4. PROJET EN COURS DE MATURATION
version lors de cette présentation2.0.1
mélange entre Spray et Akka
J'ai eu l'idée de cette présentation à la version 1.0, il était temps !

5. AKKA STREAMS
Présenté au SLUG par en février 2015Frédéric Masion
Source ~> Flow ~> Sink
Source décrit une source de données
Flow représente une transformation de ces données
Sink une opération terminale

6. AKKA STREAMS
Source ~> Flow1 ~> Flow2a ~> Sink
~> Flow2b
Fan-out / Fan-in

7. AKKA HTTP
Constuit sur Akka Streams
Internet est un tuyau
rempli de chatons

8. AKKA HTTP
Flow[HttpRequest, HttpResponse]

9. AKKA HTTP
Client et serveur
Mettre des acteurs sur HTTP

10. MODULES
akka-http-spray-json
akka-http-xml
akka-http-testkit
akka-http
akka-http-core

11. C'EST BON, MONTRE-MOI LE CODE
Les exemples sont pour la plupart tirés de la documentation
d'Akka

12. EXEMPLE SIMPLE
import akka.http.scaladsl.Http
import akka.http.scaladsl.marshallers.xml.ScalaXmlSupport._
import akka.http.scaladsl.server.Directives._
import akka.stream.ActorMaterializer
object Main extends App {
implicit val system = ActorSystem("my-system")
implicit val materializer = ActorMaterializer()
implicit val ec = system.dispatcher
val route =
path("hello") {
get {
complete {
<h1>Say hello to akka-http</h1>
}
}
}
val bindingFuture = Http().bindAndHandle(route, "localhost", 8080)
println(s"Server online at http://localhost:8080/nPress RETURN to stop...")
Console.readLine() // for the future transformations
bindingFuture
.flatMap(_.unbind()) // trigger unbinding from the port
.onComplete(_ ⇒ system.shutdown()) // and shutdown when done
}

13. EXEMPLE SIMPLE
import akka.http.scaladsl.Http
import akka.http.scaladsl.marshallers.xml.ScalaXmlSupport._
import akka.http.scaladsl.server.Directives._
import akka.stream.ActorMaterializer
object Main extends App {
implicit val system = ActorSystem("my-system")
implicit val materializer = ActorMaterializer()
implicit val ec = system.dispatcher
val route =
path("hello") {
get {
complete {
<h1>Say hello to akka-http</h1>
}
}
}
val bindingFuture = Http().bindAndHandle(route, "localhost", 8080)
println(s"Server online at http://localhost:8080/nPress RETURN to stop...")
Console.readLine() // for the future transformations
bindingFuture
.flatMap(_.unbind()) // trigger unbinding from the port
.onComplete(_ ⇒ system.shutdown()) // and shutdown when done
}

14. EXEMPLE SIMPLE
import akka.http.scaladsl.Http
import akka.http.scaladsl.marshallers.xml.ScalaXmlSupport._
import akka.http.scaladsl.server.Directives._
import akka.stream.ActorMaterializer
object Main extends App {
implicit val system = ActorSystem("my-system")
implicit val materializer = ActorMaterializer()
implicit val ec = system.dispatcher
val route =
path("hello") {
get {
complete {
<h1>Say hello to akka-http</h1>
}
}
}
val bindingFuture = Http().bindAndHandle(route, "localhost", 8080)
println(s"Server online at http://localhost:8080/nPress RETURN to stop...")
Console.readLine() // for the future transformations
bindingFuture
.flatMap(_.unbind()) // trigger unbinding from the port
.onComplete(_ ⇒ system.shutdown()) // and shutdown when done
}

15. EXEMPLE SIMPLE
import akka.http.scaladsl.Http
import akka.http.scaladsl.marshallers.xml.ScalaXmlSupport._
import akka.http.scaladsl.server.Directives._
import akka.stream.ActorMaterializer
object Main extends App {
implicit val system = ActorSystem("my-system")
implicit val materializer = ActorMaterializer()
implicit val ec = system.dispatcher
val route =
path("hello") {
get {
complete {
<h1>Say hello to akka-http</h1>
}
}
}
val bindingFuture = Http().bindAndHandle(route, "localhost", 8080)
println(s"Server online at http://localhost:8080/nPress RETURN to stop...")
Console.readLine() // for the future transformations
bindingFuture
.flatMap(_.unbind()) // trigger unbinding from the port
.onComplete(_ ⇒ system.shutdown()) // and shutdown when done
}

16. MARSHALLING/UNMARSHALLING

17. MARSHALLING/UNMARSHALLING
Comment passer d'un flux HTTP à Scala et inversement ?

18. MARSHALLING
Marshallers prédéfinis
Array[Byte]
ByteString
Array[Char]
String
akka.http.scaladsl.model.FormData
akka.http.scaladsl.model.MessageEntity
T <: akka.http.scaladsl.model.Multipart
T si ToEntityMarshaller[T] est présent

19. MARSHALLING
Résolution implicite
Si le type ToEntityMarshaller[T] est défini, il est utilisé

20. UNMARSHALLING
Unmarshallers prédéfinis
Byte
Short
Int
Long
Float
Double
Boolean
Array[Byte]
ByteString
Array[Char]
String
akka.http.scaladsl.model.FormData

21. ROUTAGE

22. LOW-LEVEL
import akka.http.scaladsl.Http
import akka.http.scaladsl.model.HttpMethods._
import akka.http.scaladsl.model._
import akka.stream.ActorMaterializer
implicit val system = ActorSystem()
implicit val materializer = ActorMaterializer()
val requestHandler: HttpRequest => HttpResponse = {
case HttpRequest(GET, Uri.Path("/"), _, _, _) =>
HttpResponse(entity = HttpEntity(ContentTypes.`text/html(UTF-8)`
,
"Hello world!"))
case HttpRequest(GET, Uri.Path("/ping"), _, _, _) =>
HttpResponse(entity = "PONG!")
case HttpRequest(GET, Uri.Path("/crash"), _, _, _) =>
sys.error("BOOM!")
case _: HttpRequest =>
HttpResponse(404, entity = "Unknown resource!")
}
Http().bindAndHandleSync(requestHandler, "localhost", 8080)

23. HIGH-LEVEL
import akka.http.scaladsl.Http
import akka.http.scaladsl.marshallers.xml.ScalaXmlSupport._
import akka.http.scaladsl.server.Directives._
import akka.stream.ActorMaterializer
implicit val system = ActorSystem()
implicit val materializer = ActorMaterializer()
val route =
get {
pathSingleSlash {
complete {
<html>
<body>Hello world!</body>
</html>
}
} ~
path("ping") {
complete("PONG!")
} ~
path("crash") {
sys.error("BOOM!")
}
}

24. // `route` will be implicitly converted to `Flow` using `RouteResult
.route2HandlerFlow`
Http().bindAndHandle(route, "localhost", 8080)

25. DIRECTIVES

26. DIRECTIVES
Intercepte la requête
Filtrage de la requête
Transformation de la requête ou réponse
Extraire des informations

27. EXEMPLE
val route =
path("order" / IntNumber) { id =>
(get | put) {
extractMethod { m =>
complete(s"Received ${m.name} request for order $id")
}
}
}

28. EXEMPLE 2
val orderGetOrPutWithMethod =
path("order" / IntNumber) & (get | put) & extractMethod
val route = orderGetOrPutWithMethod { (id, m) =>
complete(s"Received ${m.name} request for order $id")
}

29. et
PATHMATCHER
val matcher: PathMatcher1[Option[Int]] =
"foo" / "bar" / "X" ~ IntNumber.? / ("edit" | "create")
Intercepte les chemins suivants :
foo/bar/X42/edit
foo/bar/X/create

30. EXTRACTION CASE CLASS
case class Color(red: Int, green: Int, blue: Int)
val route = path("color") {
parameters('red.as[Int], 'green.as[Int], 'blue.as[Int]).as(Color)
{
color =>
// utiliser color
}
}

31. VALIDATION CASE CLASS
case class Color(name: String, red: Int, green: Int, blue: Int) {
require(!name.isEmpty, "color name must not be empty")
require(0 <= red && red <= 255, "red color component must be betwe
en 0 and 255")
require(0 <= green && green <= 255, "green color component must be
between 0 and 255")
require(0 <= blue && blue <= 255, "blue color component must be be
tween 0 and 255")
}
ValidationRejection si require ne passe pas
Par défaut : 400 Bad Request

32. TESTS

33. Pour la route suivante
val smallRoute =
get {
pathSingleSlash {
complete {
"Hello World !"
}
} ~
path("ping") {
complete("PONG !")
}
}
Test
"Hello World ! non renvoyé sur /" in {
Get() ~> smallRoute ~> check {
status === StatusCodes.OK
responseAs[String] shouldEqual "Hello World !"
}
}

34. Pour la même route ...
val smallRoute =
get {
pathSingleSlash {
complete {
"Hello World !"
}
} ~
path("ping") {
complete("PONG !")
}
}
Test
"GET sur chemin inconnu non pris en compte" in {
Get("/pouet") ~> smallRoute ~> check {
handled shouldBe false
}
}

35. VARIABLES UTILISABLES DANS LES
TESTS
entityAs
handled
header
response
status
entre autres ...

36. CLIENT
val responseFuture: Future[HttpResponse] =
Http().singleRequest(HttpRequest(uri = "http://akka.io"))

37. QUESTIONS ?

38. MERCI POUR VOTRE ÉCOUTE
Cette présentation :
@thebignet
thebignet
thebignet
talk-akka-http