Network.Wai.Log

A simple logging middleware for WAI applications that supports the 'log-*' family of packages: https://hackage.haskell.org/package/log-base

When logging to stdout using defaultOptions, the output looks like this:

2019-02-21 19:51:47 INFO my-server: Request received {
  "url": "/api/myapi",
  "body-length": "KnownLength 0",
  "method": "GET",
  "user-agent": "curl/7.54.0",
  "remote-host": "127.0.0.1:61249"
}
2019-02-21 19:51:47 INFO my-server: Sending response
2019-02-21 19:51:47 INFO my-server: Request complete {
  "status": {
    "code": 200,
    "message": "OK"
  },
  "time": {
    "process": 2.224e-3,
    "full": 2.348e-3
  }
}

Create a Middleware

mkApplicationLogger :: MonadLog m => m Middleware

Create a logging Middleware using defaultOptions

Use mkApplicationLoggerWith for custom Options

mkApplicationLoggerWith :: MonadLog m => Options -> m Middleware

Create a logging Middleware using the supplied Options

Options

data Options

Logging options

Constructors

Options

Fields

• logLevel :: LogLevel
• logRequest :: Request -> [Pair]
• logSendingResponse :: Bool
• logResponse :: Request -> Response -> ResponseTime -> [Pair]

defaultOptions :: Options

Default Options

{ logLevel = LogInfo
, logRequest = defaultLogRequest
, logSendingResponse = True
, logResponse = defaultLogResponse
}