golang 發送post請求 其body中json對象使用變量做爲value

話很少說直接上代碼

package main

//導入須要的包
import (
    "errors"
    "fmt"
    "io/ioutil"
    "net"
    "net/http"
    "os"
    "strings"
)
//獲取本地機器ip列表
func externalIP() (net.IP, error) {
    ifaces, err := net.Interfaces()
    if err != nil {
        return nil, err
    }
    for _, iface := range ifaces {
        if iface.Flags&net.FlagUp == 0 {
            continue // interface down
        }
        if iface.Flags&net.FlagLoopback != 0 {
            continue // loopback interface
        }
        addrs, err := iface.Addrs()
        if err != nil {
            return nil, err
        }
        for _, addr := range addrs {
            ip := getIpFromAddr(addr)
            if ip == nil {
                continue
            }
            return ip, nil
        }
    }
    return nil, errors.New("connected to the network?")
}
//從本地機器ip列表中找到真實ip
func getIpFromAddr(addr net.Addr) net.IP {
    var ip net.IP
    switch v := addr.(type) {
    case *net.IPNet:
        ip = v.IP
    case *net.IPAddr:
        ip = v.IP
    }
    if ip == nil || ip.IsLoopback() {
        return nil
    }
    ip = ip.To4()
    if ip == nil {
        return nil // not an ipv4 address
    }

    return ip
}

//獲取本機名稱
func getHostname() string{
    name, err := os.Hostname()
    if err != nil {
        panic(err)
    }
    return name
    //fmt.Println("hostname:", name)
}

//發送一個post請求，傳遞含有變量的json數據
func httpPostJson(getip string , gethostname string) {
    url := "https://is-cmdb-test.test.gifshow.com/cmdb-web/api/v1/machine/add"
    method := "POST"

    payload := strings.NewReader("{\"hostName\": \""+gethostname+"\",\"ip\": \""+getip+"\",\"env\":\"開發環境\",\"machineRoom\":\"DZ\",\"info\":\"\",\"label\":\"k8s\",\"user\":\"劉緒衝\"}")

    client := &http.Client {
    }
    req, err := http.NewRequest(method, url, payload)

    if err != nil {
        fmt.Println(err)
    }
    req.Header.Add("Content-Type", "application/json")
    //req.Header.Add("Cookie", "accessproxy_session=22fba8b9-dd1b-4495-bf79-020db9b1e11b; apdid=3c9fb385-1111-494a-9251-cf84935ce3c58e620eacfc6f038594c6112f2642d89a:1610612991:1")

    res, err := client.Do(req)
    defer res.Body.Close()
    body, err := ioutil.ReadAll(res.Body)

    fmt.Println(string(body))
}

func main() {
    ip, err := externalIP()
    if err != nil {
        fmt.Println(err)
    }

    fmt.Println("本機ip：",ip.String())
    //把ip和hostnmae賦值給新的變量
    getip := ip.String()
    gethostname := getHostname()
    httpPostJson(getip , gethostname)

}