Manage Cron Jobs with Codeigniter 3.0 and MySQL

I didn’t like managing all of my website’s CRON jobs via CPanel because I couldn’t easily see what my jobs were and when they will run next. So I decided to manage the CRON in my applications database and with a simple PHP script. You will need to only create 1 CRON job in Cpanel and this will subsequently run all the other jobs you define! Here are a couple easy steps on how to do it with Codeigniter 3.0.

Manage CRON Jobs with PHP/MySQL and Codeigniter 3.0

1. Create the following MySQL Database:

   CREATE TABLE `cron` (
   `id` int(5) NOT NULL,
   `name` varchar(100) DEFAULT NULL,
   `command` varchar(255) NOT NULL,
   `interval_sec` int(10) NOT NULL,
   `last_run_at` datetime DEFAULT NULL,
   `next_run_at` datetime DEFAULT NULL,
   `is_active` tinyint(1) NOT NULL DEFAULT '1'
   ) ENGINE=InnoDB DEFAULT CHARSET=utf8;

2. Create the file application/libraries/CronRunner.php with the following contents:

   <?php
   defined('BASEPATH') or exit('No direct script access allowed');
   
   class CronRunner
   {
    private $CI;
   
    public function __construct()
    {
       $this->CI =& get_instance();
    }
   
    private function calculateNextRun($obj)
    {
       return (time() + $obj->interval_sec);
    }
   
    public function run()
    {
      $query = $this->CI->db->where('is_active', 1)->where('now() >= next_run_at OR next_run_at IS NULL', '', false)->from('cron')->get();
      if ($query->num_rows() > 0) {
        $env = getenv('CI_ENV');
          foreach ($query->result() as $row) {
            $cmd = "export CI_ENV={$env} && {$row->command}";
            $this->CI->db->set('next_run_at', 'FROM_UNIXTIME('.$this->calculateNextRun($row).')', false)->where('id', $row->id)->update('cron');
            $output = shell_exec($cmd);
            $this->CI->db->set('last_run_at', 'now()', false)->where('id', $row->id)->update('cron');
          }
       } 
     }
   }

3. Create application/controllers/Cron.php with the following contents:

   <?php if (! defined('BASEPATH')) {
    exit('No direct script access allowed');
   }
   class Cron extends MY_Controller
   {
   
    public function __construct()
    {
      parent::__construct();
      if (!$this->input->is_cli_request()) {
      show_error('Direct access is not allowed');
      }
    }
   
    public function run()
    {
       $this->load->library('core/CronRunner');
       $cron = new CronRunner();
       $cron->run();
    }
   }

4. Log into Cpanel and create a Cron job that runs every 1 minute that calls the above Cron->run() method
5. Insert the jobs you want to run and the interval in the database table that we defined above!