fiberslog

README

fiberslog

Fiber middleware for structured request logging with slog.

Install

go get github.com/gringolito/fiberslog

Usage

import (
    "log/slog"

    "github.com/gofiber/fiber/v2"
    "github.com/gringolito/fiberslog"
)

app := fiber.New()
logger := slog.Default()

app.Use(fiberslog.New(fiberslog.Config{
    Logger: logger,
    Fields: []string{"latency", "status", "method", "path", "requestId"},
}))

Features

• Configurable logged fields (22 built-in fields, see reference below)
• URI skip list
• Conditional body and response body logging
• Automatic level mapping based on HTTP status code (2xx→Info, 4xx→Warn, 5xx→Error)
• Sensitive header redaction via SkipHeaders

Field Reference

The Fields config option accepts any combination of the names below. Unknown names are silently ignored. The default set is latency, status, method, url, pid.

Field	Log attribute key	Type	Description
latency	latency	time.Duration	Time to process the request
status	status	int	HTTP response status code
method	method	string	HTTP request method
url	url	string	Full original URL (includes query string)
path	path	string	Request path without query string
pid	pid	int	Process ID
ip	ip	string	Client IP address
ips	ips	string	X-Forwarded-For header value
host	host	string	Request hostname
port	port	string	Request port
protocol	protocol	string	Request protocol (http or https)
referer	referer	string	Referer header value
user-agent	user-agent	string	User-Agent header value
requestId	requestId	string	X-Request-ID response header
route	route	string	Matched Fiber route pattern
queryParams	queryParams	string	Serialized query parameters
body	body	[]byte	Request body bytes
responseBody	responseBody	[]byte	Response body bytes
bytesReceived	bytesReceived	int	Request body size in bytes
bytesSent	bytesSent	int	Response body size in bytes
requestHeaders	(one attr per header)	[]byte	All request headers (see Security)
responseHeaders	(one attr per header)	[]byte	All response headers (see Security)

Security

requestHeaders and responseHeaders log all headers verbatim, including Authorization, Cookie, and API keys. Use SkipHeaders to redact sensitive ones:

app.Use(fiberslog.New(fiberslog.Config{
    Fields:      []string{"latency", "status", "method", "requestHeaders"},
    SkipHeaders: []string{"Authorization", "Cookie"},
}))

Header name matching is case-insensitive.

Contributing

Contributions are welcome! Feel free to:

• Open an issue to report a bug or request a new feature
• Submit a pull request — please include tests for any new behavior
• Suggest ideas or improvements by starting a discussion

---

This project has moved from the Beerware License to MIT, but the spirit lives on: if we ever meet and you think this stuff is worth it, you're still very welcome to buy me a beer.

Documentation

Index

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

Functions

func New

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

New returns a fiber.Handler (middleware) that logs requests using slog. New creates a new middleware handler

Types

type Config

type Config struct {
	// Next defines a function to skip this middleware when returned true.
	//
	// Optional. Default: nil
	Next func(c *fiber.Ctx) bool

	// SkipBody defines a function to skip log  "body" field when returned true.
	//
	// Optional. Default: nil
	SkipBody func(c *fiber.Ctx) bool

	// SkipResBody defines a function to skip log  "resBody" field when returned true.
	//
	// Optional. Default: nil
	SkipResBody func(c *fiber.Ctx) bool

	// GetResBody defines a function to get ResBody.
	//  eg: when use compress middleware, resBody is unreadable. you can set GetResBody func to get readable resBody.
	//
	// Optional. Default: nil
	GetResBody func(c *fiber.Ctx) []byte

	// Skip logging for these uri
	//
	// Optional. Default: nil
	SkipURIs []string

	// Add custom slog logger.
	//
	// Optional. Default: slog.Default()
	Logger *slog.Logger

	// Add fields what you want see.
	//
	// Optional. Default: {"latency", "status", "method", "url", "pid"}
	Fields []string

	// SkipHeaders is a list of header names to exclude from requestHeaders logging.
	// Matching is case-insensitive. Use this to redact sensitive headers such as
	// Authorization or Cookie.
	// Warning: if omitted, ALL headers including credentials will be logged.
	//
	// Optional. Default: nil
	SkipHeaders []string
}