function connect(){
    $config = parse_ini_file('/var/www/website.com/db.ini');
    $con = mysqli_connect("localhost",$config['username'],$config['password'],$config['db']);
    if(!$con){
        die("Failed to connect to Database");
    }
    return $con;
}

username=user123
password=pass123
db=mydb

-rw-r--r-- 1 root root 84 /var/www/website.com/db.ini