GzipBinEncoder.scala

import akka.http.scaladsl.coding.Gzip
import akka.http.scaladsl.model._

object GzipBinEncoder extends Gzip(GzipBinEncoderFilter)

object GzipBinEncoderFilter extends (HttpMessage => Boolean) {
    override def apply(message: HttpMessage): Boolean =
        message match {
            case req: HttpRequest ⇒ req.entity.contentType.mediaType.isCompressible
            case res@HttpResponse(status, _, _, _) =>
                val mediaType = res.entity.contentType.mediaType
                (mediaType == MediaTypes.`application/octet-stream` || mediaType.isCompressible) && status.allowsEntity
        }
}