README

This package is a small extension of wrep/daemonizable-command. If no Upstart or systemd are available to set up a daemon, a simple cronjob and Symfony Lock are sufficient to produce an almost similar result.

Detailed information on Daemonizable / Endless Commands

Check out the documentation of wrep/daemonizable-command for more information on how to create endless commands: wrep/daemonizable-command

Installation

composer require mluex/endless-cron-command

Which version to use?

Version 5.* for Symfony 7 and higher
Version 4.* for Symfony 6

Usage

1. Configuration

EndlessCronCommands require symfony/lock to ensure that only one instance is executed at a time. Please configure the bundle accordingly in your .env.local, e.g.

###> symfony/lock ###
LOCK_STORE_DSN=mysql:host=127.0.0.1;dbname=app
###< symfony/lock ###

⚠️ Make sure to use a lock store that supports expiry! Check the Symfony Lock documentation for more information.

2. Implementation

Create a Symfony command that extends EndlessCronCommand and off you go. Here is a minimal example:

namespace Acme\DemoBundle\Command;

use Mluex\EndlessCronCommand\EndlessCronCommand;
use Symfony\Component\Console\Input\InputInterface;
use Symfony\Component\Console\Output\OutputInterface;

class MinimalDemoCommand extends EndlessCronCommand
{
    // This is just a normal Command::configure() method
    protected function configure(): void
    {
        $this->setName('acme:minimaldemo')
            ->setDescription('An EndlessCronCommand implementation example');
    }

    // Method will be called in an endless loop
    protected function execute(InputInterface $input, OutputInterface $output): int
    {
        // Do some work
        file_put_contents('/tmp/acme-timestamp.txt', time());
    }
}

If your command includes Monolog's FingersCrossed Log Handlers, you may want to clear them after every iteration as wrep pointed out in his documentation. EndlessCronCommand provides a method for this:

namespace Acme\DemoBundle\Command;

use Mluex\EndlessCronCommand\EndlessCronCommand;
use Psr\Log\LoggerInterface;
use Symfony\Component\Console\Input\InputInterface;
use Symfony\Component\Console\Output\OutputInterface;

class MinimalDemoCommand extends EndlessCronCommand
{
    public function __construct(
        private readonly LoggerInterface $logger,
        string $name = null
    ) {
        parent::__construct($name);
    }

    // This is just a normal Command::configure() method
    protected function configure(): void
    {
        $this->setName('acme:minimaldemo')
            ->setDescription('An EndlessCronCommand implementation example');
    }

    // Method will be called in an endless loop
    protected function execute(InputInterface $input, OutputInterface $output): int
    {
        // Do some work
        file_put_contents('/tmp/acme-timestamp.txt', time());
        
        // Clear FingersCrossed Log Handlers
        $this->clearFingersCrossedLogHandlers($this->logger);
    }
}

3. Cronjob setup

Add a cronjob to your crontab to run the command every minute.

* * * * * php /path/to/your/project/bin/console acme:minimaldemo >/dev/null 2>&1

4. Advanced usage

It may make sense to limit the runtime of an instance and restart the command regularly. Use the runtime option for this:

* * * * * php /path/to/your/project/bin/console acme:minimaldemo --runtime=600 >/dev/null 2>&1

In order to run the command's execute() method more often in the main loop (default is 5 sec), you can use the frequency option to set a lower timeout between iterations (1 sec in this example):

* * * * * php /path/to/your/project/bin/console acme:minimaldemo --frequency=1 >/dev/null 2>&1

Every iteration will refresh the lock and push its expiry time further into the future. If the command crashes, the lock will expire after the lock-ttl time and the next cronjob will start a new instance. You can set the lock-ttl to a lower value to ensure that the command is restarted more quickly after a crash:

* * * * * php /path/to/your/project/bin/console acme:minimaldemo --lock-ttl=60 >/dev/null 2>&1

TODO

Examples
Unit Tests

mluex / endless-cron-command

Maintainers

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