func ProxyTest() {
proxyAddr := "http://your IP:8080/"

httpUrl := "http://your target url"

poststr := "your  post values"

proxy, err := url.Parse(proxyAddr)
if err != nil {
log.Fatal(err)
}

netTransport := &http.Transport{
Proxy:                 http.ProxyURL(proxy),
MaxIdleConnsPerHost:   10,
ResponseHeaderTimeout: time.Second * time.Duration(5),
}

httpClient := http.Client{
Timeout:   time.Second * 10,
Transport: netTransport,
}

res, err := http.NewRequest("POST", httpUrl, strings.NewReader(poststr))
if err != nil {
log.Println(err)
return
}

res.Header.Add("content-type", "application/x-ndjson")

resp, err := httpClient.Do(res)

defer resp.Body.Close()
if resp.StatusCode != http.StatusOK {
log.Println(err)
}

c, _ := ioutil.ReadAll(resp.Body)

fmt.Println(string(c))
}

参考

https://i6448038.github.io/2017/11/11/httpAndGolang/