With this snippet we can implement the following functionalities from the global configuration file config/config.php:

• Access control to the applications in certain environments. For example, disable access in the environment of development from production server.

• IP access control to certain applications of the project. For example, to protect backend or administration zones of the project.

• To have several global configuration files of config/config.php according to the environment in which we are. For example, to define different constants for each environment.

I developed a mini-library (config/config.lib.php) to include and use in the global config file config/config.php.

<?php
/**
 * IP access control to an environment
 *
 * @param string $env environment name
 * @param array $ips IPs that has access
 * @param string $clientip client IP
 */
function envCorrecte ($env,$ips,$clientip)
{
    if (SF_ENVIRONMENT==$env)
    {
        $acces=0;
        foreach($ips as $ip)
        {
            $ipclient=substr($clientip,0,strlen($ip));
            if ($ipclient==$ip)
            {
                $acces=1;
            }
        }
        if ($acces==0)
        {
            echo "Keep away! this is not a public environment.";
            exit;
        }
    }
}
/**
 * IP access control to an application of the symfony project
 *
 * @param array $apps no public applications
 * @param array $ips IPs that has access
 * @param string $clientip client IP
 */
function appCorrecte ($apps,$ips,$clientip)
{
    // solve problem with key '0' in array
        $apps_aux[0]='';
    $apps = $apps_aux + $apps;
    //
    if (array_search(SF_APP,$apps)!=false)
    {
        $acces=0;
        foreach($ips as $ip)
        {
            $ADR=$HTTP_SERVER_VARS['REMOTE_ADDR'];
            $ipclient=substr($clientip,0,strlen($ip));
            if ($ipclient==$ip)
            {
                $acces=1;
            }
        }   
        if ($acces==0)
        {
            echo "Keep away! ".SF_APP." is not a public application.";
            exit;
        }
    }
 
}
?>

Finally config/config.php file can be like this:

<?php
include("config.lib.php");
 
/**
 * IP access control to 'env' and 'int' environments
 */
$ip_dev=array("10.138.0.","192.168.");
$ip_int=array("10.138.0.","192.168.");
envCorrecte('env',$ip_env,$HTTP_SERVER_VARS['REMOTE_ADDR']);
envCorrecte('int',$ip_int,$HTTP_SERVER_VARS['REMOTE_ADDR']);
 
/**
 * IP access control to backend applications
 */
$ip_apps=array("10.138.0.","192.168.","w.x.y.z");
$apps=array('myapp_1','myapp_2','myapp_n');
appCorrecte($apps,$ip_apps,$HTTP_SERVER_VARS['REMOTE_ADDR']);
 
/**
 * Custom config.php file for each environment
 */
include("config.".SF_ENVIRONMENT.".php");
 
/**
 * Common config.php file for all environments
 */
define("example","content1");
 
?>