go·通过 get或post请求从*http.Request中获取客户端ip地址
注意：需要放到服务器才能获取真正地址，本地测试仅得到127.0.0.1 是正常的
//ip查询
func ClientIP(r *http.Request) string {
xForwardedFor := r.Header.Get("X-Forwarded-For")
ip := strings.TrimSpace(strings.Split(xForwardedFor, ",")[0])
if ip != "" {
return ip
}
ip = strings.TrimSpace(r.Header.Get("X-Real-Ip"))
if ip != "" {
return ip
}
if ip, _, err := net.SplitHostPort(strings.TrimSpace(r.RemoteAddr)); err == nil {
return ip
}
return ""
}