Files
postgrest/src/PostgREST/Middleware.hs
T

91 lines
3.4 KiB
Haskell

{-# OPTIONS_GHC -fno-warn-orphans #-}
{-# LANGUAGE ScopedTypeVariables #-}
module PostgREST.Middleware where
import Data.Maybe (fromMaybe, isNothing)
import Data.Monoid
import Data.Text
import Data.String.Conversions (cs)
import qualified Hasql as H
import qualified Hasql.Postgres as P
import Network.HTTP.Types.Header (hAccept, hAuthorization,
hLocation)
import Network.HTTP.Types.Status (status301, status400, status415)
import Network.URI (URI (..), parseURI)
import Network.Wai (Application, Request (..),
Response, isSecure, rawPathInfo,
rawQueryString, requestHeaders,
responseLBS)
import Network.Wai.Middleware.Cors (cors)
import Network.Wai.Middleware.Gzip (def, gzip)
import Network.Wai.Middleware.Static (only, staticPolicy)
import PostgREST.App (contentTypeForAccept)
import PostgREST.Auth (setRole, jwtClaims, claimsToSQL)
import PostgREST.Config (AppConfig (..), corsPolicy)
import Prelude hiding(concat)
import qualified Data.Vector as V
import qualified Hasql.Backend as B
import qualified Data.Map.Lazy as M
runWithClaims :: forall s. AppConfig ->
(Request -> H.Tx P.Postgres s Response) ->
Request -> H.Tx P.Postgres s Response
runWithClaims conf app req = do
mapM_ H.unitEx $ stmt <$> env
app req
where
stmt = (flip $ flip B.Stmt V.empty) True
hdrs = requestHeaders req
jwtSecret = (cs $ configJwtSecret conf) :: Text
auth = fromMaybe "" $ lookup hAuthorization hdrs
anon = cs $ configAnonRole conf
claims =
fromMaybe (M.fromList []) $
case split (==' ') (cs auth) of
("Bearer" : jwt : _) -> jwtClaims jwtSecret jwt
_ -> Nothing
env = if M.member "role" claims
then jwtEnv
else setRole anon : jwtEnv
jwtEnv = claimsToSQL claims
redirectInsecure :: Application -> Application
redirectInsecure app req respond = do
let hdrs = requestHeaders req
host = lookup "host" hdrs
uriM = parseURI . cs =<< mconcat [
Just "https://",
host,
Just $ rawPathInfo req,
Just $ rawQueryString req]
isHerokuSecure = lookup "x-forwarded-proto" hdrs == Just "https"
if not (isSecure req || isHerokuSecure)
then case uriM of
Just uri ->
respond $ responseLBS status301 [
(hLocation, cs . show $ uri { uriScheme = "https:" })
] ""
Nothing ->
respond $ responseLBS status400 [] "SSL is required"
else app req respond
unsupportedAccept :: Application -> Application
unsupportedAccept app req respond = do
let
accept = lookup hAccept $ requestHeaders req
if isNothing $ contentTypeForAccept accept
then respond $ responseLBS status415 [] "Unsupported Accept header, try: application/json"
else app req respond
defaultMiddle :: Bool -> Application -> Application
defaultMiddle secure = (if secure then redirectInsecure else id)
. gzip def . cors corsPolicy
. staticPolicy (only [("favicon.ico", "static/favicon.ico")])
. unsupportedAccept