yesod/yesod/Yesod/Default/Config2.hs
2017-02-05 12:09:18 +02:00

127 lines
3.9 KiB
Haskell

{-# LANGUAGE CPP #-}
{-# LANGUAGE OverloadedStrings #-}
-- | Some next-gen helper functions for the scaffolding's configuration system.
module Yesod.Default.Config2
( -- * Locally defined
configSettingsYml
, getDevSettings
, develMainHelper
, makeYesodLogger
-- * Re-exports from Data.Yaml.Config
, applyCurrentEnv
, getCurrentEnv
, applyEnvValue
, loadYamlSettings
, loadYamlSettingsArgs
, EnvUsage
, ignoreEnv
, useEnv
, requireEnv
, useCustomEnv
, requireCustomEnv
-- * For backwards compatibility
, MergedValue (..)
, loadAppSettings
, loadAppSettingsArgs
) where
import Data.Yaml.Config
import Data.Semigroup
import Data.Aeson
import qualified Data.HashMap.Strict as H
import System.Environment (getEnvironment)
import Network.Wai (Application)
import Network.Wai.Handler.Warp
import Text.Read (readMaybe)
import Data.Maybe (fromMaybe)
import Control.Concurrent (forkIO, threadDelay)
import System.Exit (exitSuccess)
import System.Directory (doesFileExist)
import Network.Wai.Logger (clockDateCacher)
import Yesod.Core.Types (Logger (Logger))
import System.Log.FastLogger (LoggerSet)
#ifndef mingw32_HOST_OS
import System.Posix.Signals (installHandler, sigINT, Handler(Catch))
#endif
newtype MergedValue = MergedValue { getMergedValue :: Value }
instance Semigroup MergedValue where
MergedValue x <> MergedValue y = MergedValue $ mergeValues x y
-- | Left biased
mergeValues :: Value -> Value -> Value
mergeValues (Object x) (Object y) = Object $ H.unionWith mergeValues x y
mergeValues x _ = x
-- | Load the settings from the following three sources:
--
-- * Run time config files
--
-- * Run time environment variables
--
-- * The default compile time config file
loadAppSettings
:: FromJSON settings
=> [FilePath] -- ^ run time config files to use, earlier files have precedence
-> [Value] -- ^ any other values to use, usually from compile time config. overridden by files
-> EnvUsage
-> IO settings
loadAppSettings = loadYamlSettings
{-# DEPRECATED loadAppSettings "Use loadYamlSettings" #-}
-- | Same as @loadAppSettings@, but get the list of runtime config files from
-- the command line arguments.
loadAppSettingsArgs
:: FromJSON settings
=> [Value] -- ^ any other values to use, usually from compile time config. overridden by files
-> EnvUsage -- ^ use environment variables
-> IO settings
loadAppSettingsArgs = loadYamlSettingsArgs
{-# DEPRECATED loadAppSettingsArgs "Use loadYamlSettingsArgs" #-}
-- | Location of the default config file.
configSettingsYml :: FilePath
configSettingsYml = "config/settings.yml"
-- | Helper for getApplicationDev in the scaffolding. Looks up PORT and
-- DISPLAY_PORT and prints appropriate messages.
getDevSettings :: Settings -> IO Settings
getDevSettings settings = do
env <- getEnvironment
let p = fromMaybe (getPort settings) $ lookup "PORT" env >>= readMaybe
pdisplay = fromMaybe p $ lookup "DISPLAY_PORT" env >>= readMaybe
putStrLn $ "Devel application launched: http://localhost:" ++ show pdisplay
return $ setPort p settings
-- | Helper for develMain in the scaffolding.
develMainHelper :: IO (Settings, Application) -> IO ()
develMainHelper getSettingsApp = do
#ifndef mingw32_HOST_OS
_ <- installHandler sigINT (Catch $ return ()) Nothing
#endif
putStrLn "Starting devel application"
(settings, app) <- getSettingsApp
_ <- forkIO $ runSettings settings app
loop
where
loop :: IO ()
loop = do
threadDelay 100000
e <- doesFileExist "yesod-devel/devel-terminate"
if e then terminateDevel else loop
terminateDevel :: IO ()
terminateDevel = exitSuccess
-- | Create a 'Logger' value (from yesod-core) out of a 'LoggerSet' (from
-- fast-logger).
makeYesodLogger :: LoggerSet -> IO Logger
makeYesodLogger loggerSet' = do
(getter, _) <- clockDateCacher
return $! Yesod.Core.Types.Logger loggerSet' getter