Play Framework Filter for AWS Elastic Load Balancer (forward HTTP to HTTPS)

HTTPSRedirectFilter.scala

import com.typesafe.scalalogging.slf4j.Logging
import play.api.mvc._
import scala.concurrent.Future
import play.mvc.Results._
import play.api.libs.concurrent.Execution.Implicits.defaultContext

object HTTPSRedirectFilter extends Filter with Logging {

    def apply(nextFilter: (RequestHeader) => Future[SimpleResult])(requestHeader: RequestHeader): Future[SimpleResult] = {
        //play uses lower case headers.
        requestHeader.headers.get("x-forwarded-proto") match {
            case Some(header) => {
                if ("https" == header) {
                    nextFilter(requestHeader).map { result =>
                        result.withHeaders(("Strict-Transport-Security", "max-age=31536000"))
                    }
                } else {
                    Future.successful(Results.Redirect("https://" + requestHeader.host + requestHeader.uri, 301))
                }
            }
            case None => nextFilter(requestHeader)
        }
    }
}

This is Filter for Play Framework 2.2.x that enables http to https redirect, designed to work within AWS Elastic Load Balancer.

You can read more about it in this blog post:
http://www.mentful.com/2014/05/25/play-framework-filter-for-aws-elastic-load-balancer-forward-http-to-https/