golang实现反向代理

golang实现反向代理学习

package main

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

//将request转发给 http://127.0.0.1:2003
func helloHandler(w http.ResponseWriter, r *http.Request) {
    
    trueServer := "http://127.0.0.1:2003"

    url, err := url.Parse(trueServer)
    if err != nil {
        log.Println(err)
        return
    }

    proxy := httputil.NewSingleHostReverseProxy(url)
    proxy.ServeHTTP(w, r)

}

func main() {
    http.HandleFunc("/hello", helloHandler)
    log.Fatal(http.ListenAndServe(":2002", nil))
}

package main
import (
    "io"
    "net/http"
    "log"
)

func helloHandler(w http.ResponseWriter, req *http.Request) {
        io.WriteString(w, "hello, world!\n")
}

func main() {
        http.HandleFunc("/hello", helloHandler)
        log.Fatal(http.ListenAndServe(":2003", nil))
}

访问http://127.0.0.1:2002/hello，返回hello, world!

golang实现反向代理

将前端传来的/dcv/:host/请求转发到https://" + host + ":8443

package dcvproxy

import (
	"net/http"
	"strings"
	"net"
	"net/http/httputil"
	"net/url"
	"crypto/tls"
	stdlog "log"
	"os"
	"time"
	"github.com/labstack/echo/v4"
)

// Represents httpd handler.
type Handler struct {
}

// Creates handler instance.
func New() *Handler {
	return &Handler{}
}

func (h *Handler) Handle(c echo.Context) error {
	// wrap standard log to logrus
	stdLogger := stdlog.New(os.Stdout, "", stdlog.Ldate|stdlog.Lmicroseconds)
	stdLogger.SetFlags(0)
	stdLogger.SetOutput(&log2LogrusWriter{
		entry: logProxy,
	})

	// route: /dcv/:host/
	host := c.Param("Host")
	var tlsConfig = &tls.Config{
		InsecureSkipVerify: true,
	}

	dcvURL := "https://" + host + ":8443"
	target, err := url.Parse(dcvURL)
	if err != nil {
		log.Errorf("url.Parse failed: url=%s error=%v", dcvURL, err)
		return nil
	}
	var transport http.RoundTripper = &http.Transport{
		Proxy: nil, // http.ProxyFromEnvironment,
		DialContext: (&net.Dialer{
				Timeout:   30 * time.Second,
				KeepAlive: 30 * time.Second,
		}).DialContext,
		MaxIdleConns:          100,
		IdleConnTimeout:       90 * time.Second,
		TLSHandshakeTimeout:   10 * time.Second,
		ExpectContinueTimeout: 1 * time.Second,
		TLSClientConfig:       tlsConfig,
		// Set this value so that the underlying transport round-tripper
		// doesn't try to auto decode the body of objects with
		// content-encoding set to `gzip`.
		//
		// Refer:
		//    https://golang.org/src/net/http/transport.go?h=roundTrip#L1843
		DisableCompression: true,
	}
	proxy := httputil.NewSingleHostReverseProxy(target)
	proxy.Transport = transport
	proxy.ErrorLog = stdLogger
	proxy.ModifyResponse = func(r *http.Response) error {
		r.Header.Del("X-Frame-Options")
		return nil
	}
	r := c.Request()
	r.URL.Path = "/" + strings.TrimPrefix(r.URL.Path, "/dcv/" + host + "/")
	proxy.ServeHTTP(c.Response(), r)
	return nil
}