Files
postgrest/src/PostgREST/Logger.hs
T

94 lines
3.2 KiB
Haskell

{-|
Module : PostgREST.Logger
Description : Wai Middleware to log requests to stdout.
-}
module PostgREST.Logger
( middleware
, observationLogger
, init
, LoggerState
) where
import Control.AutoUpdate (defaultUpdateSettings,
mkAutoUpdate, updateAction)
import Control.Debounce
import qualified Data.ByteString.Char8 as BS
import Data.Time (ZonedTime, defaultTimeLocale, formatTime,
getZonedTime)
import qualified Network.Wai as Wai
import qualified Network.Wai.Middleware.RequestLogger as Wai
import Network.HTTP.Types.Status (status400, status500)
import System.IO.Unsafe (unsafePerformIO)
import PostgREST.Config (LogLevel (..))
import PostgREST.Observation
import Protolude
data LoggerState = LoggerState
{ stateGetZTime :: IO ZonedTime -- ^ Time with time zone used for logs
, stateLogDebouncePoolTimeout :: MVar (IO ()) -- ^ Logs with a debounce
}
init :: IO LoggerState
init = do
zTime <- mkAutoUpdate defaultUpdateSettings { updateAction = getZonedTime }
LoggerState zTime <$> newEmptyMVar
logWithDebounce :: LoggerState -> IO () -> IO ()
logWithDebounce loggerState action = do
debouncer <- tryReadMVar $ stateLogDebouncePoolTimeout loggerState
case debouncer of
Just d -> d
Nothing -> do
newDebouncer <-
let oneSecond = 1000000 in
mkDebounce defaultDebounceSettings
{ debounceAction = action
, debounceFreq = 5*oneSecond
, debounceEdge = leadingEdge -- logs at the start and the end
}
putMVar (stateLogDebouncePoolTimeout loggerState) newDebouncer
newDebouncer
middleware :: LogLevel -> (Wai.Request -> Maybe BS.ByteString) -> Wai.Middleware
middleware logLevel getAuthRole = case logLevel of
LogInfo -> requestLogger (const True)
LogWarn -> requestLogger (>= status400)
LogError -> requestLogger (>= status500)
LogCrit -> requestLogger (const False)
where
requestLogger filterStatus = unsafePerformIO $
Wai.mkRequestLogger Wai.defaultRequestLoggerSettings
{ Wai.outputFormat =
Wai.ApacheWithSettings $
Wai.defaultApacheSettings &
Wai.setApacheRequestFilter (\_ res -> filterStatus $ Wai.responseStatus res) &
Wai.setApacheUserGetter getAuthRole
, Wai.autoFlush = True
, Wai.destination = Wai.Handle stdout
}
observationLogger :: LoggerState -> LogLevel -> ObservationHandler
observationLogger loggerState logLevel obs = case obs of
o@(PoolAcqTimeoutObs _) -> do
when (logLevel >= LogError) $ do
logWithDebounce loggerState $
logWithZTime loggerState $ observationMessage o
o@(QueryErrorCodeHighObs _) -> do
when (logLevel >= LogError) $ do
logWithZTime loggerState $ observationMessage o
o@(HasqlPoolObs _) -> do
when (logLevel >= LogInfo) $ do
logWithZTime loggerState $ observationMessage o
o ->
logWithZTime loggerState $ observationMessage o
logWithZTime :: LoggerState -> Text -> IO ()
logWithZTime loggerState txt = do
zTime <- stateGetZTime loggerState
hPutStrLn stderr $ toS (formatTime defaultTimeLocale "%d/%b/%Y:%T %z: " zTime) <> txt