Request Logger

RequestLogger entrega los valores seleccionados de la petición y la respuesta a la función obligatoria LogValuesFunc. Puedes usar slog u otra biblioteca. Cada campo Log* activa la extracción de un valor; por ejemplo, LogStatus: true rellena v.Status.

Ejemplos

slog (log/slog)

Este programa completo registra la URI y el estado como JSON. Desde el repositorio de echox, ejecuta cd reference/request-logger && go run . y solicita http://localhost:1323/.

request-logger/main.go

// SPDX-License-Identifier: MIT

// This complete example is the source for the Request Logger documentation.
package main

import (
  "log/slog"
  "net/http"
  "os"

  "github.com/labstack/echo/v5"
  "github.com/labstack/echo/v5/middleware"
)

func main() {
  e := echo.New()
  logger := slog.New(slog.NewJSONHandler(os.Stdout, nil))

  e.Use(middleware.RequestLoggerWithConfig(middleware.RequestLoggerConfig{
    LogURI:      true,
    LogStatus:   true,
    HandleError: true,
    LogValuesFunc: func(c *echo.Context, v middleware.RequestLoggerValues) error {
      if v.Error != nil {
        logger.Error("request failed", "uri", v.URI, "status", v.Status, "error", v.Error)
        return nil
      }
      logger.Info("request", "uri", v.URI, "status", v.Status)
      return nil
    },
  }))

  e.GET("/", func(c *echo.Context) error {
    return c.String(http.StatusOK, "hello")
  })

  if err := e.Start(":1323"); err != nil {
    e.Logger.Error("server stopped", "error", err)
  }
}

La página importa el mismo archivo que compila la CI de documentación. v.Error recibe el error devuelto por el siguiente handler. Con HandleError: true, el manejador global escribe la respuesta antes de ejecutar LogValuesFunc; los middleware anteriores ya no pueden cambiar el estado ni el cuerpo.

fmt.Printf

En una aplicación pequeña, LogValuesFunc puede usar fmt.Printf. Activa los campos Log* de los valores que quieras leer.

Zerolog (rs/zerolog)

Pasa los valores seleccionados a Zerolog dentro de LogValuesFunc.

Zap (uber-go/zap)

Usa la misma función para enviar los valores a Zap.

Logrus (sirupsen/logrus)

Crea los campos de Logrus a partir de RequestLoggerValues.

Configuración

La tabla se genera a partir de los campos exportados de la revisión indicada de Echo. No presupone valores predeterminados en tiempo de ejecución.

RequestLoggerConfig · github.com/labstack/echo/v5@5196b9b

Las descripciones de los campos se generan a partir de comentarios del código fuente en inglés.

Campos del código fuente

Campo	Tipo	Descripción	Fuente
Skipper	Skipper	Skipper defines a function to skip middleware.	L126
BeforeNextFunc	func(c *echo.Context)	BeforeNextFunc defines a function that is called before next middleware or handler is called in chain.	L129
LogValuesFunc	func(c *echo.Context, v RequestLoggerValues) error	LogValuesFunc defines a function that is called with values extracted by logger from request/response. Mandatory.	L132
HandleError	bool	HandleError instructs logger to call global error handler when next middleware/handler returns an error. This is useful when you have custom error handler that can decide to use different status codes. A side-effect of calling global error handler is that now Response has been committed and sent to the client and middlewares up in chain can not change Response status code or response body.	L139
LogLatency	bool	LogLatency instructs logger to record duration it took to execute rest of the handler chain (next(c) call).	L142
LogProtocol	bool	LogProtocol instructs logger to extract request protocol (i.e. `HTTP/1.1` or `HTTP/2`)	L144
LogRemoteIP	bool	LogRemoteIP instructs logger to extract request remote IP. See `echo.Context.RealIP()` for implementation details.	L146
LogHost	bool	LogHost instructs logger to extract request host value (i.e. `example.com`)	L148
LogMethod	bool	LogMethod instructs logger to extract request method value (i.e. `GET` etc)	L150
LogURI	bool	LogURI instructs logger to extract request URI (i.e. `/list?lang=en&page=1`)	L152
LogURIPath	bool	LogURIPath instructs logger to extract request URI path part (i.e. `/list`)	L154
LogRoutePath	bool	LogRoutePath instructs logger to extract route path part to which request was matched to (i.e. `/user/:id`)	L156
LogRequestID	bool	LogRequestID instructs logger to extract request ID from request `X-Request-Id` header or response if request did not have value.	L158
LogReferer	bool	LogReferer instructs logger to extract request referer values.	L160
LogUserAgent	bool	LogUserAgent instructs logger to extract request user agent values.	L162
LogStatus	bool	LogStatus instructs logger to extract response status code. If handler chain returns an error, the status code is extracted from the error satisfying echo.StatusCoder interface.	L165
LogContentLength	bool	LogContentLength instructs logger to extract content length header value. Note: this value could be different from actual request body size as it could be spoofed etc.	L168
LogResponseSize	bool	LogResponseSize instructs logger to extract response content length value. Note: when used with Gzip middleware this value may not be always correct.	L171
LogHeaders	[]string	LogHeaders instructs logger to extract given list of headers from request. Note: request can contain more than one header with same value so slice of values is been logger for each given header. Note: header values are converted to canonical form with http.CanonicalHeaderKey as this how request parser converts header names to. For example, the canonical key for "accept-encoding" is "Accept-Encoding".	L177
LogQueryParams	[]string	LogQueryParams instructs logger to extract given list of query parameters from request URI. Note: request can contain more than one query parameter with same name so slice of values is been logger for each given query param name.	L180
LogFormValues	[]string	LogFormValues instructs logger to extract given list of form values from request body+URI. Note: request can contain more than one form value with same name so slice of values is been logger for each given form value name.	L183

Funciones del código fuente

Tipo	Fuente
func RequestLogger() echo.MiddlewareFunc	L395
func RequestLoggerWithConfig(config RequestLoggerConfig) echo.MiddlewareFunc	L237

Solución de problemas

panic: missing LogValuesFunc callback function for request logger middleware

LogValuesFunc es obligatoria. Asígnala antes de llamar a RequestLoggerWithConfig; el ejemplo ejecutable incluye esta función.

Los parámetros en los logs están vacíos

Activa el campo de extracción correspondiente: LogURI: true para v.URI o LogStatus: true para v.Status.