Crontab Bundle Laravel Package

Getting Started

Minimal Setup

1. Installation:

   composer require agentsib/crontab-bundle
   

   Add to AppKernel.php (Symfony2) or bundles.php (Symfony3):

   new AgentSIB\CrontabBundle\AgentSIBCrontabBundle(),
   

2. Configuration: Enable the bundle in config.yml:

   agentsib_crontab:
       commands:  # List of console commands to schedule
           - app:command1
           - app:command2
       cron_file: '%kernel.root_dir%/../crontab'  # Path to crontab file
       user: 'www-data'  # User to run cron jobs as
   

3. First Use Case: Schedule a command to run daily at midnight:

   agentsib_crontab:
       commands:
           - { command: 'app:your_command', schedule: '0 0 * * *' }
   

   Run the agentsib:crontab:generate command to write the crontab file:

   php app/console agentsib:crontab:generate
   

Implementation Patterns

Workflows

1. Defining Jobs:

   • Use YAML/XML/PHP config to define console commands and their schedules.
   • Example (YAML):

     agentsib_crontab:
         commands:
             - { command: 'app:backup', schedule: '0 2 * * 0' }  # Weekly Sunday at 2 AM
             - { command: 'app:cleanup', schedule: '0 3 * * *' }  # Daily at 3 AM
     

2. Dynamic Scheduling:

   • Use environment variables or parameters for flexible schedules:

     parameters:
         cron_backup_time: '0 4 * * *'  # Override via env: BACKUP_TIME
     agentsib_crontab:
         commands:
             - { command: 'app:backup', schedule: '%backup_time%' }
     

3. Integration with Console Commands:

   • Extend existing commands to support cron-specific logic:

     class BackupCommand extends ContainerAwareCommand {
         protected function execute(InputInterface $input, OutputInterface $output) {
             if ($this->getContainer()->getParameter('is_cron')) {
                 // Cron-specific logic (e.g., silent mode)
                 $output->setVerbosity(OutputInterface::VERBOSITY_QUIET);
             }
             // ... rest of the command
         }
     }
     

4. Generating and Managing Crontab:

   • Generate the crontab file:

     php app/console agentsib:crontab:generate
     

   • Reload cron service:

     service cron reload  # Linux
     

   • Remove old entries (if needed):

     php app/console agentsib:crontab:remove
     

Gotchas and Tips

Pitfalls

1. Outdated Package:

   • Last release in 2016 (Symfony 3 compatibility). Test thoroughly in staging.
   • May conflict with newer Symfony versions or dependencies (e.g., mtdowling/cron-expression).

2. Crontab File Permissions:

   • Ensure the generated crontab file (%kernel.root_dir%/../crontab) is writable by the cron user (e.g., www-data).
   • Debug permission issues with:

     sudo chown www-data:www-data %kernel.root_dir%/../crontab
     sudo chmod 644 %kernel.root_dir%/../crontab
     

3. Command Paths:

   • Use fully qualified command names (e.g., app:command) to avoid ambiguity.
   • Avoid spaces or special characters in command names.

4. Cron Syntax Errors:

   • Validate cron expressions using tools like crontab.guru.
   • Common errors:
     • Invalid characters (e.g., * in the wrong field).
     • Missing fields (e.g., 0 0 * * is invalid; use 0 0 * * *).

5. Logging and Debugging:

   • Check cron logs for errors:

     grep CRON /var/log/syslog
     

   • Enable Symfony debug mode to log cron job execution:

     agentsib_crontab:
         log_commands: true
     

Tips

1. Environment-Specific Schedules:

   • Use different configs for dev/prod:

     # config_dev.yml
     agentsib_crontab:
         commands:
             - { command: 'app:dev-task', schedule: '*/5 * * * *' }  # Every 5 mins in dev
     

2. Conditional Execution:

   • Add pre-flight checks in commands to skip if conditions aren’t met (e.g., environment variables):

     if (!$this->getContainer()->getParameter('enable_cron_job')) {
         return 0;
     }
     

3. Backup Old Crontab:

   • Backup /etc/crontab or the user’s crontab (crontab -l) before generating:

     sudo cp /etc/crontab /etc/crontab.bak
     

4. Testing Locally:

   • Use symfony/process to simulate cron jobs:

     $process = new Process(['php', 'app/console', 'app:your_command']);
     $process->run();
     

5. Extension Points:

   • Override the CrontabGenerator service to customize crontab generation logic:

     services:
         agentsib_crontab.generator:
             class: Your\Bundle\Crontab\CustomGenerator
             arguments: ['@service_container']
             tags:
                 - { name: agentsib_crontab.generator }