Please find below my signature a sketch of a WAI proxy server, which always redirects every request to the same URL. In the sketch, the function `magic' takes care of translating from a Network.HTTP.Conduit.Response body to Network.Wai.ResponseSource body. However, I am a at a loss as to how to write `magic' safely. The body of a Network.HTTP.Conduit.Response is a ResumableSource but the body of Network.Wai.ResponseSource is a plain source and the conversion from one to the other would seem to involve one of: * Connecting the ResumableSource to a Sink, thus regrettably forcing it all into memory, * Unwrapping the resumable source and trying to figure out what to do with the finalizer. I was originally attracted to Wai/Warp/Conduit by the prospect of building a high quality proxy server. I am building an web service that talks to AWS and, for some tasks, must proxy results back to the user. I would be very grateful if someone could explain to me how best to put together a simple, efficient proxy server with Wai and Conduit. -- Jason Dusek pgp // solidsnack // C1EBC57DC55144F35460C8DF1FD4C6C1FED18A2B
{-# LANGUAGE OverloadedStrings , RecordWildCards #-}
import Control.Applicative import Control.Monad import Data.ByteString (ByteString) import qualified Data.ByteString.Char8 as Bytes
import qualified Blaze.ByteString.Builder as Blaze import qualified Blaze.ByteString.Builder.Char.Utf8 as Blaze import Control.Monad.Trans import qualified Data.Conduit as Conduit import qualified Data.Conduit.List as Conduit import qualified Network.Wai as Wai import qualified Network.HTTP.Conduit as Conduit import qualified Network.HTTP.Types as HTTP
wai :: String -> Wai.Application wai s req@Wai.Request{..} = Conduit.withManager go where magic = undefined go manager = do request <- liftIO $ Conduit.parseUrl s Conduit.Response s _ h src <- Conduit.http request manager return $ Wai.ResponseSource s h (magic src)