proxy.md

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/v2"
    "github.com/gofiber/fiber/v2/middleware/proxy"
)

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

// 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
}

Default Config

// ConfigDefault is the default config
var ConfigDefault = Config{
    Next: nil,
}