http内网转发

package main

import (
	"io"
	"log"
	"net/http"
	"strings"
)

func main() {
	localHost := "127.0.0.1.8001"
	targetHost := "127.0.0.1:80"
	httpsServer(localHost, targetHost)

	log.Fatalln("http server down!!!")
}

func httpsServer(addr string, remote_addr string) {

	http.HandleFunc("/", func(w http.ResponseWriter, req *http.Request) {
		cli := &http.Client{}
		body := make([]byte, 0)
		n, err := io.ReadFull(req.Body, body)
		if err != nil {
			io.WriteString(w, "Request Data Error")
			return
		}
		reqUrl := "http://" + remote_addr + req.URL.Path

		req2, err := http.NewRequest(req.Method, reqUrl, strings.NewReader(string(body)))
		if err != nil {
			io.WriteString(w, "Request Error")
			return
		}
		// set request content type
		contentType := req.Header.Get("Content-Type")
		req2.Header.Set("Content-Type", contentType)
		// request
		rep2, err := cli.Do(req2)
		if err != nil {
			io.WriteString(w, "Not Found!")
			return
		}
		defer rep2.Body.Close()
		n, err = io.ReadFull(rep2.Body, body)
		if err != nil {
			io.WriteString(w, "Request Error")
			return
		}
		// set response header
		for k, v := range rep2.Header {
			w.Header().Set(k, v[0])
		}
		io.WriteString(w, string(body[:n]))
	})
	var err error = nil
	err = http.ListenAndServe(":12307", nil)
	if err != nil {
		log.Fatal("server down!!!")
	}
}