Composing Services via Finagle

gistfile1.scala

val timelineSvc = Thrift.newIface[TimelineService](...) // #1 
val tweetSvc = Thrift.newIface[TweetService](...)
val authSvc = Thrift.newIface[AuthService](...)

val authFilter = Filter.mk[Req, AuthReq, Res, Res] { (req, svc) => // #2 
  authSvc.authenticate(req) flatMap svc(_)
}

val apiService = Service.mk[AuthReq, Res] { req => 
  timelineSvc(req.userId) flatMap {tl =>
    val tweets = tl map tweetSvc.getById(_)
    Future.collect(tweets) map tweetsToJson(_) }
    } 
  } //#3 
Http.serve(":80", authFilter andThen apiService) // #4

// #1 Create a client for each service
// #2 Create new Filter to authenticate incoming requests
// #3 Create a service to convert an authenticated timeline request to a json response 
// #4 Start a new HTTP server on port 80 using the authenticating filter and our service