Skip to content

Instantly share code, notes, and snippets.

@JalfResi
Last active October 25, 2024 15:41
Show Gist options
  • Save JalfResi/6287706 to your computer and use it in GitHub Desktop.
Save JalfResi/6287706 to your computer and use it in GitHub Desktop.
Simple reverse proxy in Go
package main
import(
"log"
"net/url"
"net/http"
"net/http/httputil"
)
func main() {
remote, err := url.Parse("http://google.com")
if err != nil {
panic(err)
}
handler := func(p *httputil.ReverseProxy) func(http.ResponseWriter, *http.Request) {
return func(w http.ResponseWriter, r *http.Request) {
log.Println(r.URL)
r.Host = remote.Host
w.Header().Set("X-Ben", "Rad")
p.ServeHTTP(w, r)
}
}
proxy := httputil.NewSingleHostReverseProxy(remote)
http.HandleFunc("/", handler(proxy))
err = http.ListenAndServe(":8080", nil)
if err != nil {
panic(err)
}
}
@johnandersen777
Copy link

👍 :octocat:

@thurt
Copy link

thurt commented Jan 19, 2018

instead of using a closure, you may find creating a struct instance to be simpler. see my fork https://gist.github.com/thurt/2ae1be5fd12a3501e7f049d96dc68bb9 i think it is more idiomatic for golang

@WhyBeingAsianRapperIsSoHard

Thx

@ijt
Copy link

ijt commented Feb 24, 2020

I tried this and it came up 404 in Chrome and Safari.

@xdkxlk
Copy link

xdkxlk commented Mar 13, 2020

How to control the http timeout?

@BeforyDeath
Copy link

added r.Host = remote.Host

@nilskch
Copy link

nilskch commented May 22, 2020

I received a 404 as well. Does anyone have a solution?

@kubosuke
Copy link

kubosuke commented Jun 2, 2020

lovely!

@sokryptk
Copy link

This returns a 404, any solutions?

Copy link

ghost commented Sep 3, 2020

Does it forward the client IP?

@zack-wang
Copy link

Excellent

@dudigit
Copy link

dudigit commented Apr 3, 2021

Any solution to 404 ?

@JalfResi
Copy link
Author

Added "r.Host = remote.Host" to fix 404 issues

@lwzm
Copy link

lwzm commented Jul 16, 2021

Added "r.Host = remote.Host" to fix 404 issues

undeclared name: remote

function handler should be placed in function main:

	handler := func(p *httputil.ReverseProxy) func(http.ResponseWriter, *http.Request) {
		return func(w http.ResponseWriter, r *http.Request) {
			log.Println(r.URL)
			r.Host = remote.Host
			w.Header().Set("X-Ben", "Rad")
			p.ServeHTTP(w, r)
		}
	}

@JalfResi
Copy link
Author

Thanks @lwzm!

@abdennour
Copy link

Great!

@doolgibi
Copy link

hi, after saved this file, how can i try?

@samuelnihoul
Copy link

go run main.go
then
curl localhost:8080
I think

Copy link

ghost commented Dec 22, 2022

Made some changes to add support for ssl. And cleanup handler.

`package main

import (
"log"
"net/http"
"net/http/httputil"
"net/url"
"crypto/tls"
)

func main() {
// Replace 'target' with the URL of the server you want to proxy to
target, err := url.Parse("https://example.com")
if err != nil {
panic(err)
}

// Create a new ReverseProxy instance
proxy := httputil.NewSingleHostReverseProxy(target)
// Configure the reverse proxy to use HTTPS
proxy.Transport = &http.Transport{
    TLSClientConfig: &tls.Config{InsecureSkipVerify: true},
}
// Create a handler function that logs the URL and forwards the request to the proxy
handler := func(w http.ResponseWriter, r *http.Request) {
    log.Println(r.URL)
    r.Host = target.Host
	//w.Header().Set("X-Ben", "radi")
    proxy.ServeHTTP(w, r)
}

// Register the handler function with the HTTP server
http.HandleFunc("/", handler)

// Start the HTTP server
err = http.ListenAndServe(":3000", nil)
if err != nil {
    panic(err)
}

}`

Copy link

ghost commented Dec 22, 2022

@rjp
Copy link

rjp commented May 24, 2024

Helpful, ta, used this to transparently adjust some query parameters for certain requests.

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment