nodeJSはユーザーIPを取得する

function getClientIp(req) {
    var ipAddress;
    var forwardedIpsStr = req.header('x-forwarded-for'); 
    if (forwardedIpsStr) {
        var forwardedIps = forwardedIpsStr.split(',');
        ipAddress = forwardedIps[0];
    }
    if (!ipAddress) {
        ipAddress = req.connection.remoteAddress;
    }
    return ipAddress;
};