在这个例子中，我们将使用httptrace来获取与HTTP客户端请求有关的信息，并打印出来用于调试目的。追踪将从DNS查询开始，一直到收到响应。最后我们将以JSON格式打印结果。如果你想调试HTTP客户端的问题，这可能是个好办法。
package main
import (
"crypto/tls"
"encoding/json"
"fmt"
"io/ioutil"
"log"
"net"
"net/http"
"net/http/httptrace"
"time"
)
type Debug struct {
DNS struct{
Start string `json:"start"`
End string `json:"end"`
Host string `json:"host"`
Address []net.IPAddr `json:"address"`
Error error `json:"error"`
} `json:"dns"`
Dial struct{
Start string `json:"start"`
End string `json:"end"`
} `json:"dial"`
Connection struct{
Time string `json:"time"`
} `json:"connection"`
WroteAllRequestHeaders struct{
Time string `json:"time"`
} `json:"wrote_all_request_header"`
WroteAllRequest struct{
Time string `json:"time"`
} `json:"wrote_all_request"`
FirstReceivedResponseByte struct{
Time string `json:"time"`
} `json:"first_received_response_byte"`
}
func main() {
// Create trace struct.
trace, debug := trace()
// Prepare request with trace attached to it.
req, err := http.NewRequest(http.MethodGet, "http://localhost:8090/server/api/v1/users", nil)
if err != nil {
log.Fatalln("request error", err)
}
req = req.WithContext(httptrace.WithClientTrace(req.Context(), trace))
// MAke a request.
res, err := client().Do(req)
if err != nil {
log.Fatalln("client error", err)
}
defer res.Body.Close()
// Read response.
body, err := ioutil.ReadAll(res.Body)
if err != nil {
log.Fatal(err)
}
// Print report.
data, err := json.MarshalIndent(debug, "", " ")
fmt.Println(string(data))
fmt.Println(string(body))
}
func client() *http.Client {
return &http.Client{
Transport: transport(),
}
}
func transport() *http.Transport {
return &http.Transport{
DisableKeepAlives: true,
TLSClientConfig: tlsConfig(),
}
}
func tlsConfig() *tls.Config {
return &tls.Config{
InsecureSkipVerify: true,
}
}
func trace() (*httptrace.ClientTrace, *Debug) {
d := &Debug{}
t := &httptrace.ClientTrace{
DNSStart: func(info httptrace.DNSStartInfo) {
t := time.Now().UTC().String()
log.Println(t, "dns start")
d.DNS.Start = t
d.DNS.Host = info.Host
},
DNSDone: func(info httptrace.DNSDoneInfo) {
t := time.Now().UTC().String()
log.Println(t, "dns end")
d.DNS.End = t
d.DNS.Address = info.Addrs
d.DNS.Error = info.Err
},
ConnectStart: func(network, addr string) {
t := time.Now().UTC().String()
log.Println(t, "dial start")
d.Dial.Start = t
},
ConnectDone: func(network, addr string, err error) {
t := time.Now().UTC().String()
log.Println(t, "dial end")
d.Dial.End = t
},
GotConn: func(connInfo httptrace.GotConnInfo) {
t := time.Now().UTC().String()
log.Println(t, "conn time")
d.Connection.Time = t
},
WroteHeaders: func() {
t := time.Now().UTC().String()
log.Println(t, "wrote all request headers")
d.WroteAllRequestHeaders.Time = t
},
WroteRequest: func(wr httptrace.WroteRequestInfo) {
t := time.Now().UTC().String()
log.Println(t, "wrote all request")
d.WroteAllRequest.Time = t
},
GotFirstResponseByte: func() {
t := time.Now().UTC().String()
log.Println(t, "first received response byte")
d.FirstReceivedResponseByte.Time = t
},
}
return t, d
}
测试
2020/03/26 18:11:28 2020-03-26 18:11:28.699923 +0000 UTC dns start
2020/03/26 18:11:28 2020-03-26 18:11:28.703246 +0000 UTC dns end
2020/03/26 18:11:28 2020-03-26 18:11:28.703556 +0000 UTC dial start
2020/03/26 18:11:28 2020-03-26 18:11:28.704488 +0000 UTC dial end
2020/03/26 18:11:28 2020-03-26 18:11:28.705182 +0000 UTC conn time
2020/03/26 18:11:28 2020-03-26 18:11:28.705841 +0000 UTC wrote all request headers
2020/03/26 18:11:28 2020-03-26 18:11:28.705920 +0000 UTC wrote all request
2020/03/26 18:11:28 2020-03-26 18:11:28.707156 +0000 UTC first received response byte
{
"dns": {
"start": "2020-03-26 18:11:28.699923 +0000 UTC",
"end": "2020-03-26 18:11:28.703246 +0000 UTC",
"host": "localhost",
"address": [
{
"IP": "::1",
"Zone": ""
},
{
"IP": "127.0.0.1",
"Zone": ""
}
],
"error": null
},
"dial": {
"start": "2020-03-26 18:11:28.703556 +0000 UTC",
"end": "2020-03-26 18:11:28.704488 +0000 UTC"
},
"connection": {
"time": "2020-03-26 18:11:28.705182 +0000 UTC"
},
"wrote_all_request_header": {
"time": "2020-03-26 18:11:28.705841 +0000 UTC"
},
"wrote_all_request": {
"time": "2020-03-26 18:11:28.705920 +0000 UTC"
},
"first_received_response_byte": {
"time": "2020-03-26 18:11:28.707156 +0000 UTC"
}
}
real server responding: 2020-03-26 18:11:28.706893 +0000 UTC
