withSizeLimit

def withSizeLimit(maxBytes: Long): Directive0 

Description

Fails the stream with EntityStreamSizeException if its request entity size exceeds given limit. Limit given as parameter overrides limit configured with pekko.http.parsing.max-content-length.

The whole mechanism of entity size checking is intended to prevent certain Denial-of-Service attacks. So suggested setup is to have pekko.http.parsing.max-content-length relatively low and use withSizeLimit directive for endpoints which expects bigger entities.

See also withoutSizeLimit for skipping request entity size check.

Examples

Scala

copysourceval route = withSizeLimit(500) {
  entity(as[String]) { _ =>
    complete(HttpResponse())
  }
}

// tests:
def entityOfSize(size: Int) =
  HttpEntity(ContentTypes.`text/plain(UTF-8)`, List.fill(size)('0').mkString)

Post("/abc", entityOfSize(500)) ~> route ~> check {
  status shouldEqual StatusCodes.OK
}

Post("/abc", entityOfSize(501)) ~> Route.seal(route) ~> check {
  status shouldEqual StatusCodes.PayloadTooLarge
}

Java

copysourceimport static org.apache.pekko.http.javadsl.server.Directives.complete;
import static org.apache.pekko.http.javadsl.server.Directives.entity;
import static org.apache.pekko.http.javadsl.server.Directives.withSizeLimit;

final Route route =
    withSizeLimit(500, () -> entity(Unmarshaller.entityToString(), (entity) -> complete("ok")));

Function<Integer, HttpRequest> withEntityOfSize =
    (sizeLimit) -> {
      char[] charArray = new char[sizeLimit];
      Arrays.fill(charArray, '0');
      return HttpRequest.POST("/").withEntity(new String(charArray));
    };

// tests:
testRoute(route).run(withEntityOfSize.apply(500)).assertStatusCode(StatusCodes.OK);

testRoute(route)
    .run(withEntityOfSize.apply(501))
    .assertStatusCode(StatusCodes.PAYLOAD_TOO_LARGE);

copysourceval route = withSizeLimit(500) {
  complete(HttpResponse())
}

// tests:
def entityOfSize(size: Int) =
  HttpEntity(ContentTypes.`text/plain(UTF-8)`, List.fill(size)('0').mkString)

Post("/abc", entityOfSize(500)) ~> route ~> check {
  status shouldEqual StatusCodes.OK
}

Post("/abc", entityOfSize(501)) ~> route ~> check {
  status shouldEqual StatusCodes.OK
}

Directive withSizeLimit is implemented in terms of HttpEntity.withSizeLimit which means that in case of nested withSizeLimit directives the innermost is applied:

Scala

copysourceval route =
  withSizeLimit(500) {
    withSizeLimit(800) {
      entity(as[String]) { _ =>
        complete(HttpResponse())
      }
    }
  }

// tests:
def entityOfSize(size: Int) =
  HttpEntity(ContentTypes.`text/plain(UTF-8)`, List.fill(size)('0').mkString)
Post("/abc", entityOfSize(800)) ~> route ~> check {
  status shouldEqual StatusCodes.OK
}

Post("/abc", entityOfSize(801)) ~> Route.seal(route) ~> check {
  status shouldEqual StatusCodes.PayloadTooLarge
}

Java

copysourceimport static org.apache.pekko.http.javadsl.server.Directives.complete;
import static org.apache.pekko.http.javadsl.server.Directives.entity;
import static org.apache.pekko.http.javadsl.server.Directives.withSizeLimit;

final Route route =
    withSizeLimit(
        500,
        () ->
            withSizeLimit(
                800, () -> entity(Unmarshaller.entityToString(), (entity) -> complete("ok"))));

Function<Integer, HttpRequest> withEntityOfSize =
    (sizeLimit) -> {
      char[] charArray = new char[sizeLimit];
      Arrays.fill(charArray, '0');
      return HttpRequest.POST("/").withEntity(new String(charArray));
    };

// tests:
testRoute(route).run(withEntityOfSize.apply(800)).assertStatusCode(StatusCodes.OK);

testRoute(route)
    .run(withEntityOfSize.apply(801))
    .assertStatusCode(StatusCodes.PAYLOAD_TOO_LARGE);