Symfony Cron Bundle Laravel Package

Getting Started

Minimal Setup

1. Installation:

   composer require course-hero/symfony-cron-bundle
   

   Enable the bundle in config/bundles.php:

   return [
       // ...
       SymfonyCronBundle\SymfonyCronBundle::class => ['all' => true],
   ];
   

2. Basic Configuration (in config/packages/symfony_cron.yaml):

   symfony_cron:
       lock_service: SymfonyCronBundle\Component\Lock\LockFileService
       process_service: SymfonyCronBundle\Component\Process\ProcessService
   

3. First Use Case: Create a command to run via cron:

   php bin/console make:command DailyReport
   

   Then configure it in config/cron.yml (or via YAML/annotation):

   commands:
       app:daily-report:
           schedule: "0 0 * * *"  # Runs daily at midnight
           lock_service: "@symfony_cron.lock_file_service"
   

Implementation Patterns

Workflows

1. Locking Strategies:

   • Use LockFileService for simple file-based locks (default).
   • Replace with MemcachedLockService or RedisLockService for distributed environments:

     services:
         symfony_cron.lock_memcached_service:
             class: SymfonyCronBundle\Component\Lock\MemcachedLockService
             arguments: ["@memcached.client"]
     

2. Process Isolation:

   • Always wrap cron jobs in ProcessService to avoid orphaned locks:

     use SymfonyCronBundle\Component\Process\ProcessService;
     
     class DailyReportCommand extends Command {
         protected function execute(InputInterface $input, OutputInterface $output) {
             $processService = $this->get('symfony_cron.process_service');
             $processService->run(function() {
                 // Your job logic here
             });
         }
     }
     

3. Dynamic Scheduling:

   • Use annotations for per-command schedules:

     use SymfonyCronBundle\Annotation\Cron;
     
     /**
      * @Cron(schedule="0 3 * * 1") // Every Monday at 3 AM
      */
     class WeeklyBackupCommand extends Command { ... }
     

4. Event-Driven Triggers:

   • Combine with Symfony’s EventDispatcher for pre/post-execution hooks:

     services:
         app.cron.event_listener:
             class: App\EventListener\CronEventListener
             tags:
                 - { name: kernel.event_listener, event: cron.job.start, method: onJobStart }
     

Gotchas and Tips

Pitfalls

1. Lock Timeouts:

   • Default lock TTL is 3600 seconds (1 hour). Adjust in config:

     symfony_cron:
         lock_ttl: 1800  # 30 minutes
     

   • Debugging: Check lock files in var/cron-locks/ (default path).

2. Process Leaks:

   • If a job crashes, locks may linger. Use ProcessService mandatorily to fork processes:

     $processService->run(function() {
         // Job code here
     }, ['timeout' => 3600]); // Optional timeout
     

3. Symfony 4+ Compatibility:

   • The bundle targets Symfony 2.5+. For Symfony 4/5:
     • Use autoconfigure: true in config/packages/framework.yaml.
     • Replace services.yml with config/services.yaml.

4. Cron Expression Parsing:

   • Validate expressions with CronExpression class:

     use SymfonyCronBundle\Component\Cron\CronExpression;
     
     $expression = new CronExpression('0 0 * * *');
     if (!$expression->isValid()) {
         throw new \RuntimeException('Invalid cron expression');
     }
     

Tips

1. Logging:

   • Enable cron job logging via Monolog:

     monolog:
         handlers:
             cron:
                 type: stream
                 path: "%kernel.logs_dir%/cron.log"
                 level: debug
     

2. Testing:

   • Mock LockService and ProcessService in PHPUnit:

     $lockService = $this->createMock(LockServiceInterface::class);
     $lockService->method('lock')->willReturn(true);
     $this->container->set('symfony_cron.lock_file_service', $lockService);
     

3. Custom Lock Backends:

   • Extend AbstractLockService for databases or custom storage:

     class DatabaseLockService extends AbstractLockService {
         protected function getLockKey($jobName) {
             return "cron_lock_{$jobName}";
         }
         // Implement lock/unlock logic
     }
     

4. Environment-Specific Scheduling:

   • Use %kernel.environment% in cron expressions:

     commands:
         app:cleanup:
             schedule: "0 2 * * *"  # Prod only
             env: prod