[PHP知识库]负载均衡后，thinkphp5获取用户真实IP地址

在项目中由于使用的是单个服务器，所以代码里获取ip地址都是直接使用框架里自带的方法获取，但是负载均衡之后，获取的ip地址就不对了，每次请求都在变

/**
 * 获取用户真实IP
 * @param int $type
 * @param bool $adv
 * @return mixed
 * @Date: 2021/8/14 11:54
 * @Author wzb
 */
function get_user_ip($type = 0, $adv = true)
{
    $type      = $type ? 1 : 0;
    static $ip = null;
    if (null !== $ip) {
        return $ip[$type];
    }

    if ($adv) {
        if (isset($_SERVER['HTTP_X_FORWARDED_FOR'])) {
            $arr = explode(',', $_SERVER['HTTP_X_FORWARDED_FOR']);
            $pos = array_search('unknown', $arr);
            if (false !== $pos) {
                unset($arr[$pos]);
            }
            $ip = trim(current($arr));
        } elseif (isset($_SERVER['HTTP_CLIENT_IP'])) {
            $ip = $_SERVER['HTTP_CLIENT_IP'];
        } elseif (isset($_SERVER['REMOTE_ADDR'])) {
            $ip = $_SERVER['REMOTE_ADDR'];
        }
    } elseif (isset($_SERVER['HTTP_X_FORWARDED_FOR'])) {
        $arr = explode(',', $_SERVER['HTTP_X_FORWARDED_FOR']);
        $pos = array_search('unknown', $arr);
        if (false !== $pos) {
            unset($arr[$pos]);
        }
        $ip = trim(current($arr));
    } elseif (isset($_SERVER['REMOTE_ADDR'])) {
        $ip = $_SERVER['REMOTE_ADDR'];
    }
    // IP地址合法验证
    $long = sprintf("%u", ip2long($ip));
    $ip   = $long ? array($ip, $long) : array('0.0.0.0', 0);
    return $ip[$type];
}