logger.md

Logger

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

Table of Contents

• Signatures
• Examples
• Config
• Default Config
• Constants

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 remote IP and Port

app.Use(logger.New(logger.Config{
        Format:     "[${ip}]:${port} ${status} - ${method} ${path}\n",
}))

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"
	TagPort              = "port"
	TagIP                = "ip"
	TagIPs               = "ips"
	TagHost              = "host"
	TagMethod            = "method"
	TagPath              = "path"
	TagURL               = "url"
	TagUA                = "ua"
	TagLatency           = "latency"
	TagStatus            = "status"      // response status
	TagResBody           = "resBody"     // response body
        TagReqHeaders        = "reqHeaders"
	TagQueryStringParams = "queryParams" // request query parameters
	TagBody              = "body"        // request body
	TagBytesSent         = "bytesSent"
	TagBytesReceived     = "bytesReceived"
	TagRoute             = "route"
	TagError             = "error"
	TagHeader            = "header:"     // DEPRECATED: Use TagReqHeader instead
	TagReqHeader         = "reqHeader:"  // request header
	TagRespHeader        = "respHeader:" // response 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"
)