echo/website/content/middleware/logger.md

+++ title = "Logger" [menu.side] name = "Logger" parent = "middleware" weight = 5 +++

Logger Middleware

Logger middleware logs the information about each HTTP request.

Usage

e.Use(middleware.Logger())

Sample Output

{"time":"2016-05-10T07:02:25-07:00","remote_ip":"::1","method":"GET","uri":"/","status":200, "latency":55653,"latency_human":"55.653µs","rx_bytes":0,"tx_bytes":13}

Custom Configuration

Usage

e := echo.New()
e.Use(middleware.LoggerWithConfig(middleware.LoggerConfig{
  Format: "method=${method}, uri=${uri}, status=${status}\n",
}))

Example above uses a Format which logs request method and request URI.

Sample Output

method=GET, uri=/hello, status=200

Configuration

LoggerConfig struct {
  // Skipper defines a function to skip middleware.
  Skipper Skipper

  // Log format which can be constructed using the following tags:
  //
  // - time_rfc3339
  // - id (Request ID - Not implemented)
  // - remote_ip
  // - uri
  // - host
  // - method
  // - path
  // - referer
  // - user_agent
  // - status
  // - latency (In microseconds)
  // - latency_human (Human readable)
  // - bytes_in (Bytes received)
  // - bytes_out (Bytes sent)
  //
  // Example "${remote_ip} ${status}"
  //
  // Optional. Default value DefaultLoggerConfig.Format.
  Format string `json:"format"`

  // Output is a writer where logs are written.
  // Optional. Default value os.Stdout.
  Output io.Writer
}

Default Configuration

DefaultLoggerConfig = LoggerConfig{
  Skipper: defaultSkipper,
  Format: `{"time":"${time_rfc3339}","remote_ip":"${remote_ip}",` +
    `"method":"${method}","uri":"${uri}","status":${status}, "latency":${latency},` +
    `"latency_human":"${latency_human}","bytes_in":${bytes_in},` +
    `"bytes_out":${bytes_out}}` + "\n",
  Output: os.Stdout,
}