使用Go快速創建簡單反向代理服務

package main import ( "flag" "fmt" "net/http" "net/http/httputil" "net/url" "strings" ) //代理對象 var proxyObj *httputil.ReverseProxy //代理的服務器url var proxyUrl string var proxyUrlObj *url.URL func serveReverseProxy(res http.ResponseWriter, req *http.Request) { host := req.Host req.URL.Host = proxyUrlObj.Host req.URL.Scheme = proxyUrlObj.Scheme req.Header.Set("X-Forwarded-Host", host) if len(req.Header.Get("X-Real-IP")) <= 0 { //服務器直接請求的host，如果已經設置就不重複設置 req.Header.Set("X-Real-IP", host) } //req.Host = proxyUrlObj.Host //將代理髮送請求header中的Host指定爲原始host,雖然這個個Header,但存儲的位置在req.Host req.Host = host proxyObj.ServeHTTP(res, req) } //創建代理對象 func creatProxy() { proxyUrlObj, _ = url.Parse(proxyUrl) proxyObj = httputil.NewSingleHostReverseProxy(proxyUrlObj) } func isDoProxy(res http.ResponseWriter, req *http.Request) bool { path := req.URL.Path //當請求path爲/__p_set__時動態設置代理的目標url if strings.EqualFold(path, "/__p_set__") { query := req.URL.Query() u := query.Get("url") if len(u) > 0 { proxyUrl = u creatProxy() } res.WriteHeader(http.StatusOK) fmt.Fprintf(res, "{\"message\":\"proxyUrl:%s\"}", proxyUrl) return true } else if nil == proxyObj { creatProxy() } return true } //代理服務 func handleRequestAndRedirect(res http.ResponseWriter, req *http.Request) { if isDoProxy(res, req) { serveReverseProxy(res, req) } } func main() { var port string flag.StringVar(&proxyUrl, "url", "http://10.200.193.68/", "") flag.StringVar(&port, "port", "80", "") flag.Parse() fmt.Println("server is starting\nlisten: " + port + "\nproxyUrl: " + proxyUrl) http.HandleFunc("/", handleRequestAndRedirect) if err := http.ListenAndServe(":"+port, nil); err != nil { panic(err) } }