Logger

Logger middleware for Fiber that logs HTTP request/response details.

Table of Contents

Signatures

func New(config ...Config) fiber.Handler

Examples

First ensure the appropriate packages are imported

import (
"github.com/gofiber/fiber/v2"
"github.com/gofiber/fiber/v2/middleware/logger"
)

Initialization / Default Config

// Default middleware config
app.Use(logger.New())

Logging Request ID

app.Use(requestid.New())
​
​app​.​Use​(​logger​.​New​(logger.​Config​{
// For more options, see the Config section
Format​: "${pid} ${locals:requestid} ${status} - ${method} ${path}​\n​"​,
}))

Changing TimeZone & TimeFormat

app.Use(logger.New(logger.Config{
Format: "${pid} ${status} - ${method} ${path}\n",
TimeFormat: "02-Jan-2006",
TimeZone: "America/New_York",
}))

Custom File Writer

file, err := os.OpenFile("./123.log", os.O_RDWR|os.O_CREATE|os.O_APPEND, 0666)
if err != nil {
log.Fatalf("error opening file: %v", err)
}
defer file.Close()
​
app.Use(logger.New(logger.Config{
Output: file,
}))

Config

// Config defines the config for middleware.
type Config struct {
// Next defines a function to skip this middleware when returned true.
//
// Optional. Default: nil
Next func(c *fiber.Ctx) bool
​
// Format defines the logging tags
//
// Optional. Default: [${time}] ${status} - ${latency} ${method} ${path}\n
Format string
​
// TimeFormat https://programming.guide/go/format-parse-string-time-date-example.html
//
// Optional. Default: 15:04:05
TimeFormat string
​
// TimeZone can be specified, such as "UTC" and "America/New_York" and "Asia/Chongqing", etc
//
// Optional. Default: "Local"
TimeZone string
​
// TimeInterval is the delay before the timestamp is updated
//
// Optional. Default: 500 * time.Millisecond
TimeInterval time.Duration
​
// Output is a writter where logs are written
//
// Default: os.Stderr
Output io.Writer
}

Default Config

var ConfigDefault = Config{
Next: nil,
Format: "[${time}] ${status} - ${latency} ${method} ${path}\n",
TimeFormat: "15:04:05",
TimeZone: "Local",
TimeInterval: 500 * time.Millisecond,
Output: os.Stderr,
}

Constants

// Logger variables
const (
TagPid = "pid"
TagTime = "time"
TagReferer = "referer"
TagProtocol = "protocol"
TagIP = "ip"
TagIPs = "ips"
TagHost = "host"
TagMethod = "method"
TagPath = "path"
TagURL = "url"
TagUA = "ua"
TagLatency = "latency"
TagStatus = "status" // response status
TagBody = "body" // request body
TagBytesSent = "bytesSent"
TagBytesReceived = "bytesReceived"
TagRoute = "route"
TagError = "error"
TagHeader = "header:" // request header
TagQuery = "query:" // request query
TagForm = "form:" // request form
TagCookie = "cookie:" // request cookie
TagLocals = "locals:"
​
// colors
TagBlack = "black"
TagRed = "red"
TagGreen = "green"
TagYellow = "yellow"
TagBlue = "blue"
TagMagenta = "magenta"
TagCyan = "cyan"
TagWhite = "white"
TagReset = "reset"
)