golang中http请求

var httpSerever *http.Client = &http.Client{}
func HttpRequest(method, url string, headers map[string]string) ([]byte, error) {
    req, err := http.NewRequest(method, url, nil)
    if err != nil {
        return nil, err
    }
    if headers != nil && len(headers) != 0 {
        for k, v := range headers{
            req.Header.Add(k, v)
        }
    }
    respBytes, err := httpDo(req)
    return respBytes, err
}
func httpDo(req *http.Request) ([]byte, error) {
    resp, err := httpSerever.Do(req)
    if err != nil {
        return nil, errors.New("RetryMarkup" + err.Error())
    }
    defer resp.Body.Close()
    if resp.StatusCode != http.StatusOK {
        return nil, fmt.Errorf("RetryMarkup http get error : url=%v , statusCode=%v", req.URL, resp.StatusCode)
    }
    return ioutil.ReadAll(resp.Body)
}