fiber/docs/api/middleware/proxy.md

id, title

id	title
proxy	Proxy

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

Signatures

// Balancer create a load balancer among multiple upstrem servers.
func Balancer(config Config) fiber.Handler
// Forward performs the given http request and fills the given http response.
func Forward(addr string, clients ...*fasthttp.Client) fiber.Handler
// Do performs the given http request and fills the given http response.
func Do(c *fiber.Ctx, addr string, clients ...*fasthttp.Client) error
// DoRedirects performs the given http request and fills the given http response while following up to maxRedirectsCount redirects.
func DoRedirects(c *fiber.Ctx, addr string, maxRedirectsCount int, clients ...*fasthttp.Client) error
// DoDeadline performs the given request and waits for response until the given deadline.
func DoDeadline(c *fiber.Ctx, addr string, deadline time.Time, clients ...*fasthttp.Client) error
// DoTimeout performs the given request and waits for response during the given timeout duration.
func DoTimeout(c *fiber.Ctx, addr string, timeout time.Duration, clients ...*fasthttp.Client) error
// DomainForward the given http request based on the given domain and fills the given http response
func DomainForward(hostname string, addr string, clients ...*fasthttp.Client) fiber.Handler
// BalancerForward performs the given http request based round robin balancer and fills the given http response
func BalancerForward(servers []string, clients ...*fasthttp.Client) fiber.Handler

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:

// if target https site uses a self-signed certificate, you should
// call WithTlsConfig before Do and Forward
proxy.WithTlsConfig(&tls.Config{
    InsecureSkipVerify: true,
})
// if you need to use global self-custom client, you should use proxy.WithClient.
proxy.WithClient(&fasthttp.Client{
    NoDefaultUserAgentHeader: true, 
    DisablePathNormalizing:   true,
})

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

// If you want to forward with a specific domain. You have to use proxy.DomainForward.
app.Get("/payments", proxy.DomainForward("docs.gofiber.io", "http://localhost:8000"))

// Forward to url with local custom client
app.Get("/gif", proxy.Forward("https://i.imgur.com/IWaBepg.gif", &fasthttp.Client{
    NoDefaultUserAgentHeader: true, 
    DisablePathNormalizing:   true,
}))

// 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
})

// Make proxy requests while following redirects
app.Get("/proxy", func(c *fiber.Ctx) error {
    if err := proxy.DoRedirects(c, "http://google.com", 3); err != nil {
        return err
    }
    // Remove Server header from response
    c.Response().Header.Del(fiber.HeaderServer)
    return nil
})

// Make proxy requests and wait up to 5 seconds before timing out
app.Get("/proxy", func(c *fiber.Ctx) error {
    if err := proxy.DoTimeout(c, "http://localhost:3000", time.Second * 5); err != nil {
        return err
    }
    // Remove Server header from response
    c.Response().Header.Del(fiber.HeaderServer)
    return nil
})

// Make proxy requests, timeout a minute from now
app.Get("/proxy", func(c *fiber.Ctx) error {
    if err := proxy.DoDeadline(c, "http://localhost", time.Now().Add(time.Minute)); 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
    },
}))

// Or this way if the balancer is using https and the destination server is only using http.
app.Use(proxy.BalancerForward([]string{
    "http://localhost:3001",
    "http://localhost:3002",
    "http://localhost:3003",
}))

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 
    
    // Client is custom client when client config is complex. 
    // Note that Servers, Timeout, WriteBufferSize, ReadBufferSize and TlsConfig 
    // will not be used if the client are set.
    Client *fasthttp.LBClient
}

Default Config

var ConfigDefault = Config{
    Next:           nil,
    ModifyRequest:  nil,
    ModifyResponse: nil,
    Timeout:        fasthttp.DefaultLBClientTimeout,
}