fiber/middleware/proxy

Proxy

Proxy middleware for Fiber that allows you to proxy requests to multiple servers.

Table of Contents

• Signatures
• Examples
• Config
• Default Config

Signatures

func Balancer(config Config) fiber.Handler
func Forward(addr string) fiber.Handler
func Do(c fiber.Ctx, addr string) error

Examples

Import the middleware package that is part of the Fiber web framework

import (
	"github.com/gofiber/fiber/v3"
	"github.com/gofiber/fiber/v3/middleware/proxy"
)

After you initiate your Fiber app, you can use the following possibilities:

// if target https site uses a self-signed certificate, you should
// call WithTlsConfig before Do and Forward
proxy.WithTlsConfig(&tls.Config{
    InsecureSkipVerify: true,
})

// Forward to url
app.Get("/gif", proxy.Forward("https://i.imgur.com/IWaBepg.gif"))

// Make request within handler
app.Get("/:id", func(c fiber.Ctx) error {
	url := "https://i.imgur.com/"+c.Params("id")+".gif"
	if err := proxy.Do(c, url); err != nil {
		return err
	}
	// Remove Server header from response
	c.Response().Header.Del(fiber.HeaderServer)
	return nil
})

// Minimal round robin balancer
app.Use(proxy.Balancer(proxy.Config{
	Servers: []string{
		"http://localhost:3001",
		"http://localhost:3002",
		"http://localhost:3003",
	},
}))

// Or extend your balancer for customization
app.Use(proxy.Balancer(proxy.Config{
	Servers: []string{
		"http://localhost:3001",
		"http://localhost:3002",
		"http://localhost:3003",
	},
	ModifyRequest: func(c fiber.Ctx) error {
		c.Request().Header.Add("X-Real-IP", c.IP())
		return nil
	},
	ModifyResponse: func(c fiber.Ctx) error {
		c.Response().Header.Del(fiber.HeaderServer)
		return nil
	},
}))

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

	// Servers defines a list of <scheme>://<host> HTTP servers,
	//
	// which are used in a round-robin manner.
	// i.e.: "https://foobar.com, http://www.foobar.com"
	//
	// Required
	Servers []string

	// ModifyRequest allows you to alter the request
	//
	// Optional. Default: nil
	ModifyRequest fiber.Handler

	// ModifyResponse allows you to alter the response
	//
	// Optional. Default: nil
	ModifyResponse fiber.Handler
	
	// Timeout is the request timeout used when calling the proxy client
	//
	// Optional. Default: 1 second
	Timeout time.Duration

	// Per-connection buffer size for requests' reading.
	// This also limits the maximum header size.
	// Increase this buffer if your clients send multi-KB RequestURIs
	// and/or multi-KB headers (for example, BIG cookies).
	ReadBufferSize int
    
	// Per-connection buffer size for responses' writing.
	WriteBufferSize int

	// tls config for the http client
	TlsConfig *tls.Config
}

Default Config

// ConfigDefault is the default config
var ConfigDefault = Config{
    Next:           nil,
    ModifyRequest:  nil,
    ModifyResponse: nil,
    Timeout:        fasthttp.DefaultLBClientTimeout,
}