Safe Haskell	Safe-Inferred
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 Data.ByteString.Builder (byteString)
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 = byteString pong
    len = fromIntegral $ BS.length pong

Synopsis

type ApacheLogger = Request -> Status -> Maybe Integer -> IO ()
withStdoutLogger :: (ApacheLogger -> IO a) -> IO a
type ServerPushLogger = Request -> ByteString -> Integer -> IO ()
data ApacheLoggerActions
apacheLogger :: ApacheLoggerActions -> ApacheLogger
serverpushLogger :: ApacheLoggerActions -> ServerPushLogger
logRotator :: ApacheLoggerActions -> IO ()
logRemover :: ApacheLoggerActions -> IO ()
initLoggerUser :: ToLogStr user => Maybe (Request -> Maybe user) -> IPAddrSource -> LogType -> IO FormattedTime -> IO ApacheLoggerActions
initLogger :: IPAddrSource -> LogType -> IO FormattedTime -> IO ApacheLoggerActions
data IPAddrSource
- = FromSocket
- | FromHeader
- | FromHeaderCustom [HeaderName]
- | FromFallback
- | FromRequest (Request -> ByteString)
data LogType' a where
- LogNone :: LogType' LogStr
- LogStdout :: BufSize -> LogType' LogStr
- LogStderr :: BufSize -> LogType' LogStr
- LogFileNoRotate :: FilePath -> BufSize -> LogType' LogStr
- LogFile :: FileLogSpec -> BufSize -> LogType' LogStr
- LogFileTimedRotate :: TimedFileLogSpec -> BufSize -> LogType' LogStr
- LogCallback :: forall a. (a -> IO ()) -> IO () -> LogType' a
type LogType = LogType' LogStr
data FileLogSpec = FileLogSpec {
- log_file :: FilePath
- log_file_size :: Integer
- log_backup_number :: Int
}
showSockAddr :: SockAddr -> NumericAddress
logCheck :: LogType -> IO ()
clockDateCacher :: IO (DateCacheGetter, DateCacheUpdater)
type ZonedDate = FormattedTime
type DateCacheGetter = IO ZonedDate
type DateCacheUpdater = IO ()

High level functions

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

Apache style logger.

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

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 () Source #

HTTP/2 server push logger in Apache style.

Creating a logger

data ApacheLoggerActions Source #

Function set of Apache style logger.

apacheLogger :: ApacheLoggerActions -> ApacheLogger Source #

The Apache logger.

serverpushLogger :: ApacheLoggerActions -> ServerPushLogger Source #

The HTTP/2 server push logger.

logRotator :: ApacheLoggerActions -> IO () Source #

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

logRemover :: ApacheLoggerActions -> IO () Source #

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

initLoggerUser :: ToLogStr user => Maybe (Request -> Maybe user) -> IPAddrSource -> LogType -> IO FormattedTime -> IO ApacheLoggerActions Source #

Creating ApacheLogger according to LogType.

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

Types

data IPAddrSource Source #

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. This picks either `X-Real-IP` or `X-Forwarded-For` depending on which of these headers comes first in the ordered list of request headers. If the `X-Forwarded-For` header is picked, the value will be assumed to be a comma-separated list of IP addresses. The value will be parsed, and the left-most IP address will be used (which is mostly likely to be the actual client IP address).
FromHeaderCustom [HeaderName]	From a custom HTTP header, useful in proxied environment. The header value will be assumed to be a comma-separated list of IP addresses. The value will be parsed, and the left-most IP address will be used (which is mostly likely to be the actual client IP address). Note that this still works as expected for a single IP address.
FromFallback	Just like `FromHeader`, but falls back on the peer address if header is not found.
FromRequest (Request -> ByteString)	This gives you the most flexibility to figure out the IP source address from the `Request`. The returned `ByteString` is used as the IP source address.

data LogType' a where #

Logger Type.

Constructors

LogNone
Fields :: LogType' LogStr No logging.
LogStdout
Fields :: BufSize -> LogType' LogStr Logging to stdout. `BufSize` is a buffer size for each capability.
LogStderr
Fields :: BufSize -> LogType' LogStr Logging to stderr. `BufSize` is a buffer size for each capability.
LogFileNoRotate
Fields :: FilePath -> BufSize -> LogType' LogStr Logging to a file. `BufSize` is a buffer size for each capability.
LogFile
Fields :: FileLogSpec -> BufSize -> LogType' LogStr Logging to a file. `BufSize` is a buffer size for each capability. File rotation is done on-demand.
LogFileTimedRotate
Fields :: TimedFileLogSpec -> BufSize -> LogType' LogStr Logging to a file. `BufSize` is a buffer size for each capability. Rotation happens based on check specified in `TimedFileLogSpec`.
LogCallback
Fields :: forall a. (a -> IO ()) -> IO () -> LogType' a Logging with a log and flush action. run flush after log each message.

type LogType = LogType' LogStr #

data FileLogSpec #

The spec for logging files

Constructors

FileLogSpec
Fields log_file :: FilePath log_file_size :: Integer Max log file size (in bytes) before requiring rotation. log_backup_number :: Int Max number of rotated log files to keep around before overwriting the oldest one.

Utilities

showSockAddr :: SockAddr -> NumericAddress Source #

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

logCheck :: LogType -> IO () Source #

Backward compability

clockDateCacher :: IO (DateCacheGetter, DateCacheUpdater) Source #

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 Source #

A type for zoned date.

type DateCacheGetter = IO ZonedDate Source #

Getting cached ZonedDate.

type DateCacheUpdater = IO () Source #

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