Safe Haskell	None
Language	Haskell2010

Network.Wai.Logger

Contents

High level functions
Creating a logger
Types
Utilities
Backward compability

Description

Apache style logger for WAI applications.

An example:

{-# LANGUAGE OverloadedStrings #-}
module Main where

import Blaze.ByteString.Builder (fromByteString)
import Control.Monad.IO.Class (liftIO)
import qualified Data.ByteString.Char8 as BS
import Network.HTTP.Types (status200)
import Network.Wai (Application, responseBuilder)
import Network.Wai.Handler.Warp (run)
import Network.Wai.Logger (withStdoutLogger, ApacheLogger)

main :: IO ()
main = withStdoutLogger $ \aplogger ->
    run 3000 $ logApp aplogger

logApp :: ApacheLogger -> Application
logApp aplogger req response = do
    liftIO $ aplogger req status (Just len)
    response $ responseBuilder status hdr msg
  where
    status = status200
    hdr = [("Content-Type", "text/plain")]
    pong = "PONG"
    msg = fromByteString pong
    len = fromIntegral $ BS.length pong

Synopsis

High level functions

type ApacheLogger = Request -> Status -> Maybe Integer -> IO () #

Apache style logger.

withStdoutLogger :: (ApacheLogger -> IO a) -> IO a #

Executing a function which takes ApacheLogger. This ApacheLogger writes log message to stdout. Each buffer (4K bytes) is flushed every second.

type ServerPushLogger = Request -> ByteString -> Integer -> IO () #

HTTP/2 server push logger in Apache style.

Creating a logger

data ApacheLoggerActions #

Function set of Apache style logger.

apacheLogger :: ApacheLoggerActions -> ApacheLogger #

The Apache logger.

serverpushLogger :: ApacheLoggerActions -> ServerPushLogger #

The HTTP/2 server push logger.

logRotator :: ApacheLoggerActions -> IO () #

This is obsoleted. Rotation is done on-demand. So, this is now an empty action.

logRemover :: ApacheLoggerActions -> IO () #

Removing resources relating to Apache logger. E.g. flushing and deallocating internal buffers.

initLogger :: IPAddrSource -> LogType -> IO FormattedTime -> IO ApacheLoggerActions #

Creating ApacheLogger according to LogType.

Types

data IPAddrSource #

Source from which the IP source address of the client is obtained.

Constructors

FromSocket	From the peer address of the HTTP connection.
FromHeader	From X-Real-IP: or X-Forwarded-For: in the HTTP header.
FromFallback	From the peer address if header is not found.

data LogType :: * #

Constructors

LogNone
LogStdout BufSize
LogStderr BufSize
LogFileNoRotate FilePath BufSize
LogFile FileLogSpec BufSize
LogCallback (LogStr -> IO ()) (IO ())

data FileLogSpec :: * #

Constructors

FileLogSpec
Fields log_file :: FilePath log_file_size :: Integer log_backup_number :: Int

Utilities

showSockAddr :: SockAddr -> NumericAddress #

Convert SockAddr to NumericAddress. If the address is IPv4-embedded IPv6 address, the IPv4 is extracted.

logCheck :: LogType -> IO () #

Backward compability

clockDateCacher :: IO (DateCacheGetter, DateCacheUpdater) #

Returning DateCacheGetter and DateCacheUpdater.

Note: Since version 2.1.2, this function uses the auto-update package internally, and therefore the DateCacheUpdater value returned need not be called. To wit, the return value is in fact an empty action.

type ZonedDate = FormattedTime #

A type for zoned date.

type DateCacheGetter = IO ZonedDate #

Getting cached ZonedDate.

type DateCacheUpdater = IO () #

Updateing cached ZonedDate. This should be called every second. See the source code of withStdoutLogger.