求助， golang http post 请求问题

期望结果:

正确获取 itop rest api 返回的工单数据

当我使用 Python 的 requests 库时，这一切都很正常，获取数据成功（如果我覆盖默认 headers，获取的结果如 golang 版本的一样。

这是 Python 的代码:

#!/usr/bin/python3
import requests, json

HOST = "http://192.168.17.22:8096/itop/webservices/rest.php?version=1.3"

json_str = json.dumps({
    "operation":
    "core/get",
    "class":
    "UserRequest",
    "key":
    "SELECT UserRequest WHERE operational_status = 'ongoing'",
    "output_fields":
    "request_type,servicesubcategory_name,urgency,origin,caller_id_friendlyname,impact,title,description",
})
json_data = {
    "auth_user": "admin",
    "auth_pwd": "goodjob@123",
    "json_data": json_str
}


# secure_rest_services
def get():
    r = requests.post(HOST, data=json_data)
    return r


if __name__ == "__main__":
    result = get()
    print(result.json())

输出

{'objects': {'UserRequest::7': {'code': 0, 'message': '', 'class': 'UserRequest', 'key': '7', 'fields': {'request_type': 'service_request', 'servicesubcategory_name': '钉钉权限开通', 'urgency': '4', 'origin': 'portal', 'caller_id_friendlyname': 'x 阿里合作项目负责人', 'impact': '1', 'title': '溫江|A-222|wb-xxxxxxxx', 'description': '<p>this is a test approve...</p>'}}, 'UserRequest::6': {'code': 0, 'message': '', 'class': 'UserRequest', 'key': '6', 'fields': {'request_type': 'service_request', 'servicesubcategory_name': '钉钉权限开通', 'urgency': '3', 'origin': 'portal', 'caller_id_friendlyname': 'x 阿里合作项目负责人', 'impact': '1', 'title': '成都|Xa-111|wb-xx111111', 'description': '<p>這是一個測試用的用戶需求</p>'}}}, 'code': 0, 'message': 'Found: 2'}

下面时 golang 版本的 post 请求

主函数：

package main

import (
	"bytes"
	"encoding/json"
	"fmt"
	"io/ioutil"
	"log"
	"net/http"
	"strconv"
)

// 釘釘應用程序的 agentid
const (
	ITOP_URL = `http://192.168.17.22:8096/itop/webservices/rest.php?version=1.3`
)

func main() {
	request_auth := new(RequestAuth)
	request_data := new(RequestData)
	request_auth.AuthUser = "admin"
	request_auth.AuthPwd = "goodjob@123"

	request_data.Operation = "core/get"
	request_data.Class = "UserRequest"
	request_data.Key = "SELECT UserRequest WHERE operational_status = \"ongoing\""
	request_data.OutPutFields = "request_type,servicesubcategory_name,urgency,origin,caller_id_friendlyname,impact,title,description"
	req_data, err := json.Marshal(request_data)
	if err != nil {
		panic(err)
	}
	request_auth.JsonData = string(req_data)

	jsonData, err := json.Marshal(request_auth)
	if err != nil {
		panic(err)
	}
	reader := bytes.NewReader(jsonData)
	result := Post(ITOP_URL, reader)
	fmt.Println(string(result))
}

func Post(url string, reader *bytes.Reader) []byte {
	request, err := http.NewRequest("POST", url, reader)
	if err != nil {
		panic(err)
	}
	request.Header.Set("Content-Type", "application/json")
	request.Header.Set("Content-Length", strconv.Itoa(reader.Len()))
	client := http.Client{}
	resp, err := client.Do(request)
	if err != nil {
		log.Fatal(err.Error())
	}
	defer resp.Body.Close()
	respBytes, _ := ioutil.ReadAll(resp.Body)
	return respBytes
}

post 携带的数据模型

package main

// UserRequest structure
type Base struct {
	Code    int    `json:"code"`
	Message string `json:"message"`
}

type Fileds struct {
	RequestType            string `json:"request_type"`
	ServiceSubcategoryName string `json:"servicesubcategory_name"`
	Urgency                string `json:"urgency"`
	Origin                 string `json:"origin"`
	CallerIdFriendlyName   string `json:"caller_id_friendlyname"`
	Impact                 string `json:"impact"`
	Title                  string `json:"title"`
	Description            string `json:"description"`
}

type ResponseContent struct {
	Code    int    `json:"code"`
	Message string `json:"message"`
	Class   string `json:"class"`
	Key     string `json:"key"`
	Filed   Fileds `json:"fields"`
}

type Response struct {
	Base
	Object map[string]ResponseContent `json:"objects"`
}

// Request api data struct
type RequestData struct {
	Operation    string `json:"operation"`
	Class        string `json:"class"`
	Key          string `json:"key"`
	OutPutFields string `json:"output_fields"`
}

type RequestAuth struct {
	AuthUser string `json:"auth_user"`
	AuthPwd  string `json:"auth_pwd"`
	// JsonData RequestData `json:"json_data"`
	JsonData string `json:"json_data"`
}

输出:

{"code":5,"message":"Error: Missing parameter 'auth_user'"}

我猜这应该是 itop 需要 post 请求携带某个 header ？但我折腾了太久，直到实在没有办法才发帖求助。

求大佬们指点，(拜谢