HttpUtil.ts

import * as http from "http";

export class HttpUtil {
    static getClientIp(req: http.IncomingMessage) {
        var ipAddress;
        // The request may be forwarded from local web server.
        var forwardedIpsStr = req.headers['x-forwarded-for'] as string | undefined;
        if (forwardedIpsStr) {
            // 'x-forwarded-for' header may return multiple IP addresses in
            // the format: "client IP, proxy 1 IP, proxy 2 IP" so take the
            // the first one
            var forwardedIps = forwardedIpsStr.split(',');
            ipAddress = forwardedIps[0];
        }
        if (!ipAddress) {
            // If request was not forwarded
            ipAddress = req.connection.remoteAddress;
        }
        // Remove prefix ::ffff:
        return ipAddress ? ipAddress.replace(/^::ffff:/, '') : '';
    };
}