获取真实ip

package main

import (
    "io/ioutil"
    "log"
    "net/http"
    "os"
    "os/signal"
    . "反向代理/util"
)

type ProxyHandler struct {
}

func (*ProxyHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
    defer func() {
        if err := recover(); err != nil {
            w.WriteHeader(500)
            log.Println(err)
        }
    }()
    if r.URL.Path == "/a" {
        log.Println(r.RemoteAddr)

        newreq, _ := http.NewRequest(r.Method, "http://localhost:9091", r.Body)
        CLoneHead(r.Header, newreq.Header) //将请求头写入到模拟的请求头中去
        newreq.Header.Add("x-forwarded-for", r.RemoteAddr) //将用户ip写入到代理请求头中去
        newreq.Header.Add("Authorization", "Basic c2hlbnlpOjEyMw==") //把BasicAuth的用户名和密码添加到header中，这样才可以过被代理的ip的验证

        newresponse, _ := http.DefaultClient.Do(newreq)
        getHeader := w.Header()
        CLoneHead(newresponse.Header, getHeader) //拷贝响应头 给客户端
        w.WriteHeader(newresponse.StatusCode)    // 写入http status

        defer newresponse.Body.Close()
        res_cont, _ := ioutil.ReadAll(newresponse.Body)
        w.Write(res_cont) // 写入响应给客户端
        return
    }
    w.Write([]byte("default index"))
}

func main() {
    http.ListenAndServe(":8080", &ProxyHandler{})
    c := make(chan os.Signal)
    signal.Notify(c, os.Interrupt)
    s := <-c
    log.Println(s)

}