golang http forward转发实现

启动服务

mux := http.NewServeMux()
mux.HandleFunc("/", handler)
srv := &http.Server{
        Addr:    ":2222",
        Handler: mux,
}
srv.ListenAndServe()

转发http请求

func handler(w http.ResponseWriter, req *http.Request) {
	body, err := ioutil.ReadAll(req.Body)
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	req.Body = ioutil.NopCloser(bytes.NewReader(body))
	url := fmt.Sprintf("%s://%s%s", "http", "xxx.com", req.RequestURI)

	proxyReq, err := http.NewRequest(req.Method, url, bytes.NewReader(body))
	//头信息拷贝
	proxyReq.Header = make(http.Header)
	for h, val := range req.Header {
		proxyReq.Header[h] = val
	}
	//头信息修正
	//proxyReq.Header.Set("Authorization", "xxx")
	//proxyReq.Header.Set("User-Agent","Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/78.0.3904.108 Safari/537.36")
	//proxyReq.Header.Set("Host","xxx")
	//proxyReq.Header.Set("Origin","xxx")
	//proxyReq.Header.Set("Referer","xxx")

	httpClient := &http.Client{}
	resp, err := httpClient.Do(proxyReq)
	if err != nil {
		http.Error(w, err.Error(), http.StatusBadGateway)
		return
	}
	defer resp.Body.Close()
	//拷贝返回体
	for name, values := range resp.Header {
		w.Header()[name] = values
	}
	w.Header().Set("Access-Control-Allow-Origin", "*")
	w.WriteHeader(resp.StatusCode)
	io.Copy(w, resp.Body)
}

参考:

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