Request Logger

RequestLogger passes selected request and response values to a required LogValuesFunc callback. Use that callback to write to slog or another logger. Each Log* field controls which value is collected; for example, LogStatus: true populates v.Status.

Examples

slog (log/slog)

This complete program logs the URI and status as JSON. From the echox checkout, run cd reference/request-logger && go run ., then request http://localhost:1323/.

// 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)
  }
}

The page imports the same file that documentation CI compiles. v.Error is set when the next handler returns an error; there is no extra configuration field for it. With HandleError: true, Echo’s global error handler writes the response before LogValuesFunc runs, so earlier middleware cannot then change its status or body.

fmt.Printf

For a small application, LogValuesFunc can call fmt.Printf instead of slog. Keep the same callback signature and enable each value you read with its matching Log* field.

Zerolog (rs/zerolog)

Pass v.URI, v.Status, and other selected values to your Zerolog logger inside LogValuesFunc.

Zap (uber-go/zap)

Pass the selected values to Zap inside the same callback. Echo does not require a particular logging library.

Logrus (sirupsen/logrus)

Build Logrus fields from RequestLoggerValues inside LogValuesFunc.

Configuration

The table is generated from the exported fields in the recorded Echo revision. It does not claim runtime defaults.

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

Fields from package source
Field	Type	Description	Source
`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

Functions from package source
Type	Source
`func RequestLogger() echo.MiddlewareFunc`	L395
`func RequestLoggerWithConfig(config RequestLoggerConfig) echo.MiddlewareFunc`	L237

Troubleshooting

panic: missing LogValuesFunc callback function for request logger middleware

LogValuesFunc is required. Set it before calling RequestLoggerWithConfig; the runnable example above includes the callback.

Parameters in logs are empty

Enable the corresponding extraction field, such as LogURI: true for v.URI or LogStatus: true for v.Status. Values not selected in the config remain empty.