graphql-engine/server/src-lib/Hasura/Server/Middleware.hs
Robert 1ff3723ed8 server: assorted minor clean-up around HTTP managers
- consistent qualified imports
- less convoluted initialization of pro logging HTTP manager
- pass pro HTTP manager directly instead of via Has
- remove some dead healthcheck code

PR-URL: https://github.com/hasura/graphql-engine-mono/pull/3639
GitOrigin-RevId: dfa7b9c62d1842a07a8514cdb77f1ed86064fb06
2022-02-16 07:09:47 +00:00

69 lines
2.3 KiB
Haskell

module Hasura.Server.Middleware
( corsMiddleware,
)
where
import Control.Applicative
import Data.ByteString qualified as B
import Data.CaseInsensitive qualified as CI
import Data.Text.Encoding qualified as TE
import Hasura.Prelude
import Hasura.Server.Cors
import Hasura.Server.Utils
import Network.HTTP.Types qualified as HTTP
import Network.Wai
corsMiddleware :: CorsPolicy -> Middleware
corsMiddleware policy app req sendResp = do
let origin = getRequestHeader "Origin" $ requestHeaders req
maybe (app req sendResp) handleCors origin
where
handleCors origin = case cpConfig policy of
CCDisabled _ -> app req sendResp
CCAllowAll -> sendCors origin
CCAllowedOrigins ds
-- if the origin is in our cors domains, send cors headers
| bsToTxt origin `elem` dmFqdns ds -> sendCors origin
-- if current origin is part of wildcard domain list, send cors
| inWildcardList ds (bsToTxt origin) -> sendCors origin
-- otherwise don't send cors headers
| otherwise -> app req sendResp
sendCors :: B.ByteString -> IO ResponseReceived
sendCors origin =
case requestMethod req of
"OPTIONS" -> sendResp $ respondPreFlight origin
_ -> app req $ sendResp . injectCorsHeaders origin
respondPreFlight :: B.ByteString -> Response
respondPreFlight origin =
setHeaders (mkPreFlightHeaders requestedHeaders) $
injectCorsHeaders origin emptyResponse
emptyResponse = responseLBS HTTP.status204 [] ""
requestedHeaders =
fromMaybe "" $
getRequestHeader "Access-Control-Request-Headers" $
requestHeaders req
injectCorsHeaders :: B.ByteString -> Response -> Response
injectCorsHeaders origin = setHeaders (mkCorsHeaders origin)
mkPreFlightHeaders allowReqHdrs =
[ ("Access-Control-Max-Age", "1728000"),
("Access-Control-Allow-Headers", allowReqHdrs),
("Content-Length", "0"),
("Content-Type", "text/plain charset=UTF-8")
]
mkCorsHeaders origin =
[ ("Access-Control-Allow-Origin", origin),
("Access-Control-Allow-Credentials", "true"),
( "Access-Control-Allow-Methods",
B.intercalate "," $ TE.encodeUtf8 <$> cpMethods policy
)
]
setHeaders hdrs = mapResponseHeaders (\h -> mkRespHdrs hdrs ++ h)
mkRespHdrs = map (\(k, v) -> (CI.mk k, v))