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
    TagResBody                = "resBody"    // response body
    TagQueryStringParams            = "queryParams"    // request query parameters
    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"
)