View file hrm-saas-2.5.7/script/app/Http/Middleware/CheckForMaintenanceMode.php

<?php namespace App\Http\Middleware;

use Closure;
use Illuminate\Contracts\Foundation\Application;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\Response;


class CheckForMaintenanceMode
{

    protected $request;
    protected $app;

    public function __construct(Application $app, Request $request)
    {
        $this->app = $app;
        $this->request = $request;
    }

    public function handle($request, Closure $next)
    {
        $ip = $this->request->getClientIp();
        $allowed = array('27.251.192.2', '27.251.192.3', '27.251.192.4');
        if ($this->app->isDownForMaintenance() && !in_array($ip, $allowed)) {
            return Response::view('maintenance', array(), 503);
        }

        return $next($request);
    }

}