Part-DB.Part-DB-server/config/bootstrap.php

<?php
/**
 * This file is part of Part-DB (https://github.com/Part-DB/Part-DB-symfony)
 *
 * Copyright (C) 2019 Jan Böhmer (https://github.com/jbtronics)
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 *
 */

use Symfony\Component\Dotenv\Dotenv;

require dirname(__DIR__).'/vendor/autoload.php';

// Load cached env vars if the .env.local.php file exists
// Run "composer dump-env prod" to create it (requires symfony/flex >=1.2)
if (is_array($env = @include dirname(__DIR__).'/.env.local.php')) {
    $_SERVER += $env;
    $_ENV += $env;
} elseif (!class_exists(Dotenv::class)) {
    throw new RuntimeException('Please run "composer require symfony/dotenv" to load the ".env" files configuring the application.');
} else {
    // load all the .env files
    (new Dotenv(false))->loadEnv(dirname(__DIR__).'/.env');
}

$_SERVER['APP_ENV'] = $_ENV['APP_ENV'] = ($_SERVER['APP_ENV'] ?? $_ENV['APP_ENV'] ?? null) ?: 'dev';
$_SERVER['APP_DEBUG'] = $_SERVER['APP_DEBUG'] ?? $_ENV['APP_DEBUG'] ?? 'prod' !== $_SERVER['APP_ENV'];
$_SERVER['APP_DEBUG'] = $_ENV['APP_DEBUG'] = (int) $_SERVER['APP_DEBUG'] || filter_var($_SERVER['APP_DEBUG'], FILTER_VALIDATE_BOOLEAN) ? '1' : '0';