server: try environment variables if flags are missing, closes #45

server/src-exec/Main.hs

@@ -7,6 +7,7 @@ import           Ops
 
 import           Data.Time.Clock            (getCurrentTime)
 import           Options.Applicative
+import           System.Environment         (lookupEnv)
 import           System.Exit                (exitFailure)
 import           Web.Spock.Core             (runSpockNoBanner, spockT)
 
@@ -38,7 +39,7 @@ data ServeOptions
   , soTxIso         :: !Q.TxIsolation
   , soRootDir       :: !(Maybe String)
   , soAccessKey     :: !(Maybe AccessKey)
-  , soCorsConfig    :: !CorsConfig
+  , soCorsConfig    :: !CorsConfigFlags
   , soWebHook       :: !(Maybe T.Text)
   , soEnableConsole :: !Bool
   } deriving (Show, Eq)
@@ -93,25 +94,32 @@ mkAuthMode mAccessKey mWebHook =
     (Nothing, Nothing)    -> return AMNoAuth
     (Just key, Nothing)   -> return $ AMAccessKey key
     (Nothing, Just _)     -> throwError $
-      "Fatal Error : --auth-hook requires --access-key to be set"
+      "Fatal Error : --auth-hook (HASURA_GRAPHQL_AUTH_HOOK)"
+      ++ " requires --access-key (HASURA_GRAPHQL_ACCESS_KEY) to be set"
     (Just key, Just hook) -> return $ AMAccessKeyAndHook key hook
 
 main :: IO ()
 main = withStdoutLogger ravenLogGen $ \rlogger -> do
   (RavenOptions rci ravenMode) <- parseArgs
-  ci <- either ((>> exitFailure) . (putStrLn . connInfoErrModifier))
-    return $ mkConnInfo rci
+  mEnvDbUrl <- lookupEnv "HASURA_GRAPHQL_DATABASE_URL"
+  ci <- either ((>> exitFailure) . putStrLn . connInfoErrModifier)
+    return $ mkConnInfo mEnvDbUrl rci
   printConnInfo ci
   case ravenMode of
     ROServe (ServeOptions port cp isoL mRootDir mAccessKey corsCfg mWebHook enableConsole) -> do
+      mFinalAccessKey <- considerEnv "HASURA_GRAPHQL_ACCESS_KEY" mAccessKey
+      mFinalWebHook <- considerEnv "HASURA_GRAPHQL_AUTH_HOOK" mWebHook
       am <- either ((>> exitFailure) . putStrLn) return $
-        mkAuthMode mAccessKey mWebHook
+        mkAuthMode mFinalAccessKey mFinalWebHook
+      finalCorsDomain <- fromMaybe "*" <$> considerEnv "HASURA_GRAPHQL_CORS_DOMAIN" (ccDomain corsCfg)
+      let finalCorsCfg =
+            CorsConfigG finalCorsDomain $ ccDisabled corsCfg
       initialise ci
       migrate ci
       pool <- Q.initPGPool ci cp
       runSpockNoBanner port $ do
         putStrLn $ "server: running on port " ++ show port
-        spockT id $ app isoL mRootDir rlogger pool am corsCfg enableConsole
+        spockT id $ app isoL mRootDir rlogger pool am finalCorsCfg enableConsole
     ROExport -> do
       res <- runTx ci fetchMetadata
       either ((>> exitFailure) . printJSON) printJSON res
@@ -147,3 +155,7 @@ main = withStdoutLogger ravenLogGen $ \rlogger -> do
         ++ "\n    Port: " ++ show (Q.connPort ci)
         ++ "\n    User: " ++ Q.connUser ci
         ++ "\n    Database: " ++ Q.connDatabase ci
+
+    -- if flags given are Nothing consider it's value from Env
+    considerEnv _ (Just t) = return $ Just t
+    considerEnv e Nothing  = fmap T.pack <$> lookupEnv e

server/src-lib/Hasura/Server/Init.hs

@@ -75,9 +75,10 @@ parseRawConnInfo =
 connInfoErrModifier :: String -> String
 connInfoErrModifier s = "Fatal Error : " ++ s
 
-mkConnInfo :: RawConnInfo -> Either String Q.ConnInfo
-mkConnInfo (RawConnInfo mHost mPort mUser pass mURL mDB opts) =
-  case (mHost, mPort, mUser, mDB, mURL) of
+mkConnInfo :: Maybe String -> RawConnInfo -> Either String Q.ConnInfo
+mkConnInfo mEnvDbUrl (RawConnInfo mHost mPort mUser pass mURL mDB opts) = do
+  let mFinalDBUrl = ifNothingTakeEnv mURL
+  case (mHost, mPort, mUser, mDB, mFinalDBUrl) of
 
     (Just host, Just port, Just user, Just db, Nothing) ->
       return $ Q.ConnInfo host port user pass db opts
@@ -87,10 +88,12 @@ mkConnInfo (RawConnInfo mHost mPort mUser pass mURL mDB opts) =
     _ -> throwError $ "Invalid options. "
                     ++ "Expecting all database connection params "
                     ++ "(host, port, user, dbname, password) or "
-                    ++ "database-url"
+                    ++ "database-url (HASURA_GRAPHQL_DATABASE_URL)"
   where
-    invalidUrlMsg = "Invalid database-url. "
+    invalidUrlMsg = "Invalid database-url (HASURA_GRAPHQL_DATABASE_URL). "
                     ++ "Example postgres://foo:bar@example.com:2345/database"
+    ifNothingTakeEnv Nothing = mEnvDbUrl
+    ifNothingTakeEnv t       = t
 
 readIsoLevel :: String -> Either String Q.TxIsolation
 readIsoLevel isoS =
@@ -147,21 +150,22 @@ parseAccessKey = optional $ strOption ( long "access-key" <>
                              help "Secret access key, required to access this instance"
                            )
 
-data CorsConfig
-  = CorsConfig
-  { ccDomain   :: !T.Text
+data CorsConfigG a
+  = CorsConfigG
+  { ccDomain   :: !a
   , ccDisabled :: !Bool
   } deriving (Show, Eq)
 
-parseCorsConfig :: Parser CorsConfig
+type CorsConfigFlags = CorsConfigG (Maybe T.Text)
+type CorsConfig = CorsConfigG T.Text
+
+parseCorsConfig :: Parser CorsConfigFlags
 parseCorsConfig =
-  CorsConfig
-  <$> strOption ( long "cors-domain" <>
+  CorsConfigG
+  <$> optional (strOption ( long "cors-domain" <>
                   metavar "CORS DOMAIN" <>
-                  value "*" <>
-                  showDefault <>
                   help "The domain, including scheme and port, to allow CORS for"
-                )
+                 ))
   <*> switch ( long "disable-cors" <>
                help "Disable CORS handling"
              )

server/test/Main.hs

@@ -234,7 +234,7 @@ raven_app :: RavenLogger -> PGQ.PGPool -> IO Application
 raven_app rlogger pool =
   do
     _ <- liftIO $ runExceptT $ Q.runTx pool defTxMode resetStateTx
-    let corsCfg = CorsConfig "*" True  -- cors is disabled
+    let corsCfg = CorsConfigG "*" True  -- cors is disabled
     spockAsApp $ spockT id $ app Q.Serializable Nothing rlogger pool AMNoAuth corsCfg True -- no access key and no webhook
 
 main :: IO ()
@@ -242,7 +242,7 @@ main = withStdoutLogger ravenLogGen $ \rlogger -> do
   Options rci cp args <- parseArgs
 
   ci <- either ((>> exitFailure) . (putStrLn . connInfoErrModifier))
-    return $ mkConnInfo rci
+    return $ mkConnInfo Nothing rci
 
   pool <- Q.initPGPool ci cp