A simple google reverse proxy in Golang

grproxy.go

// grproxy project main.go
package main

import (
	"net/http"
	"net/http/httputil"
	"net/url"

	"strings"
)


func main() {

	target, _ := url.Parse("https://www.google.com")
	r := &httputil.ReverseProxy{
		Director: func(req *http.Request) {
			req.URL.Scheme = target.Scheme
			req.URL.Host = target.Host
			req.Host = target.Host //这才是关键
			req.URL.Path = singleJoiningSlash(target.Path, req.URL.Path)
			if target.RawQuery == "" || req.URL.RawQuery == "" {
				req.URL.RawQuery = target.RawQuery + req.URL.RawQuery
			} else {
				req.URL.RawQuery = target.RawQuery + "&" + req.URL.RawQuery
			}
		},
	}

	http.Handle("/", r)
	http.ListenAndServeTLS(":443", "public.crt", "private.pem", nil)
}

func singleJoiningSlash(a, b string) string {
	aslash := strings.HasSuffix(a, "/")
	bslash := strings.HasPrefix(b, "/")
	switch {
	case aslash && bslash:
		return a + b[1:]
	case !aslash && !bslash:
		return a + "/" + b
	}
	return a + b
}

// openssl genrsa -out private.pem 2048
// openssl req -new -x509 -sha256 -key private.pem -out public.crt -days 99999