fiber/middleware/logger

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 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"
)