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

Automating tasks in web applications can significantly enhance efficiency and reliability. In CodeIgniter 3.0, integrating cron jobs with MySQL allows developers to schedule tasks like database backups, email notifications, and data cleanups seamlessly.

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!

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