问题:
- 我正在转发到一个 HTTPS 地址。
- 我想看看为什么删除
req.Host = req.URL.Host
导致它失败。而不是返回{"Code":"OBRI.FR.Request.Invalid","Id":"c37baec213dd1227","Message":"An error hoccured when parsing the request arguments","Errors":[{ "ErrorCode":"UK.OBIE.Header.Missing","Message":"Missing request header 'x-fapi-financial-id' for method parameter of type String","Url":"https://docs. ob.forgerock.financial/errors#UK.OBIE.Header.Missing"}]}
它返回一个404
。 - 我想跟踪代理返回的调用
httputil。当我取消注释
正在生成。req.Host = req.URL.Host
行时,NewSingleHostReverseProxy
给出这样的请求:
$ curl http://localhost:8989/open-banking/v2.0/accounts
下面的代码(main.go
):
package main
import (
"log"
"net/http"
"net/http/httputil"
"net/url"
)
func main() {
target, err := url.Parse("https://rs.aspsp.ob.forgerock.financial:443")
log.Printf("forwarding to -> %s%s\n", target.Scheme, target.Host)
if err != nil {
log.Fatal(err)
}
proxy := httputil.NewSingleHostReverseProxy(target)
http.HandleFunc("/", func(w http.ResponseWriter, req *http.Request) {
// https://stackoverflow.com/questions/38016477/reverse-proxy-does-not-work
// https://forum.golangbridge.org/t/explain-how-reverse-proxy-work/6492/7
// https://stackoverflow.com/questions/34745654/golang-reverseproxy-with-apache2-sni-hostname-error
req.Host = req.URL.Host // if you remove this line the request will fail... I want to debug why.
proxy.ServeHTTP(w, req)
})
err = http.ListenAndServe(":8989", nil)
if err != nil {
panic(err)
}
}
最佳答案
将 proxy.Transport 字段设置为在委托(delegate)给默认传输之前转储请求的实现:
package main
import (
"fmt"
"log"
"net/http"
"net/http/httputil"
"net/url"
)
type DebugTransport struct{}
func (DebugTransport) RoundTrip(r *http.Request) (*http.Response, error) {
b, err := httputil.DumpRequestOut(r, false)
if err != nil {
return nil, err
}
fmt.Println(string(b))
return http.DefaultTransport.RoundTrip(r)
}
func main() {
target, _ := url.Parse("https://example.com:443")
log.Printf("forwarding to -> %s\n", target)
proxy := httputil.NewSingleHostReverseProxy(target)
proxy.Transport = DebugTransport{}
http.HandleFunc("/", func(w http.ResponseWriter, req *http.Request) {
req.Host = req.URL.Host
proxy.ServeHTTP(w, req)
})
log.Fatal(http.ListenAndServe(":8989", nil))
}
这个程序的输出看起来像这样:
2018/10/26 13:06:35 forwarding to -> https://example.com:443
GET / HTTP/1.1
Host: example.com:443
User-Agent: HTTPie/0.9.4
Accept: */*
Accept-Encoding: gzip, deflate
X-Forwarded-For: 127.0.0.1
或者,在删除 req.Host 分配后:
2018/10/26 13:06:54 forwarding to -> https://example.com:443
GET / HTTP/1.1
Host: localhost:8989
User-Agent: HTTPie/0.9.4
Accept: */*
Accept-Encoding: gzip, deflate
X-Forwarded-For: 127.0.0.1
由于网络服务器经常使用 Host header 将请求路由到正确的虚拟主机或后端服务器,因此意外的 Host header (上例中的“localhost:8989”)导致服务器响应是有道理的与 404。
使用 httputil.ReverseProxy 设置主机 header 通常使用 Director
函数完成:
target, err := url.Parse("https://example.com:443")
if err != nil {
log.Fatal(err)
}
log.Printf("forwarding to -> %s\n", target)
proxy := httputil.NewSingleHostReverseProxy(target)
d := proxy.Director
proxy.Director = func(r *http.Request) {
d(r) // call default director
r.Host = target.Host // set Host header as expected by target
}
log.Fatal(http.ListenAndServe(":8989", proxy))
关于go - 如何调试 httputil.NewSingleHostReverseProxy,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/52986853/