client.go

package main

import (
	"fmt"
	"io"
	"log"
	"net/http"
	"net/url"
)

func main() {
	var urls []string
	for i := 0; i < 1000; i++ {
		urls = append(urls, fmt.Sprintf("http://google.com/%d.html", i))
	}

	proxyURL, err := url.Parse("http://localhost:8080")
	if err != nil {
		log.Fatal("Error parsing proxy URL:", err)
	}
	client := &http.Client{
		Transport: &http.Transport{
			Proxy: http.ProxyURL(proxyURL),
		},
	}

	for _, link := range urls {
		req, err := http.NewRequest("GET", link, nil)
		if err != nil {
			log.Println("Error creating request for:", link, err)
			continue
		}
		resp, err := client.Do(req)
		if err != nil {
			log.Println("Error making request for:", link, err)
			continue
		}
		body, err := io.ReadAll(resp.Body)
		resp.Body.Close()
		if err != nil {
			log.Println("Error reading response from:", link, err)
			continue
		}
		log.Printf("URL: %s, Status: %s, Body: %v bytes\n", link, resp.Status, len(body))
	}
	select {}
}

proxy.go

package main

import (
	"io"
	"log"
	"net/http"
	_ "net/http/pprof"
	"net/url"
	
	"github.com/quic-go/quic-go/http3"
)

func main() {
	client := &http.Client{
		Transport: &http3.RoundTripper{},
	}

	proxyHandler := func(w http.ResponseWriter, r *http.Request) {
		// Use the incoming request's host for the upstream URL
		upstreamHost := r.Host
		upstreamURL, err := url.Parse("https://" + upstreamHost)
		if err != nil {
			http.Error(w, "Error parsing upstream URL", http.StatusInternalServerError)
			return
		}
		r.URL = upstreamURL
		r.Host = upstreamURL.Host
		r.RequestURI = "" // Clear the RequestURI to prevent errors in outgoing requests

		log.Println("handling request to", r.URL)

		// Forward the request using HTTP/3
		resp, err := client.Do(r)
		if err != nil {
			http.Error(w, "Error making HTTP/3 request", http.StatusBadGateway)
			return
		}
		defer resp.Body.Close()

		for key, values := range resp.Header {
			for _, value := range values {
				w.Header().Add(key, value)
			}
		}
		w.WriteHeader(resp.StatusCode)
		if _, err := io.Copy(w, resp.Body); err != nil {
			log.Println("Error copying response body:", err)
		}
	}

	http.HandleFunc("/", proxyHandler)
	log.Println("Starting proxy server on :8080")
	log.Fatal(http.ListenAndServe(":8080", nil))
}