Unable to start a worker using process monitor `s6-overlay`

[PAXANDDOS]

Hello! I'm having quite an issue with starting a worker using s6-overlay. It's a process monitor almost like supervisor but created specifically to use inside docker containers. The worker simply won't start: the queue is not processed and the worker is not getting registered in log files.

/etc/s6-overlay/s6-rc.d/resque/run

#!/command/execlineb -S1

/var/www/app/vendor/bin/resque worker:start --config=/var/www/app/config/queue.yml

Although it does work if ran manually inside the container:

/var/www/app$: vendor/bin/resque worker:start --config=/var/www/app/config/queue.yml
###### or
/var/www/app$: /var/www/app/vendor/bin/resque worker:start --config=/var/www/app/config/queue.yml
###### or
/var/www/app$: /etc/s6-overlay/s6-rc.d/resque/run

I've already made an issue in s6-overlay, please see it for more info: just-containers/s6-overlay#517

[PAXANDDOS]

The problem was identified by the developer of s6-overlay here: https://github.com/just-containers/s6-overlay/issues/517#issuecomment-1433387471

It appears that worker somehow invokes the stty command, making it terminal-dependant thus blocking execution using process monitors (may be a problem not for s6-overlay only but also for supervisord)

I couldn't find anything stty-related in the code, but there were a bunch of results regarding stty in symfony/console repository, maybe php-resque somehow enables stty through the symfony/console?

[PAXANDDOS]

Finally found a workaround! So since my application also uses Symfony Console I can bring commands to the application level and "wrap" resque commands. Unfortunately, the library has no constructive Console Application (it's set within the executable file) thus the process is a bit more complicated.

Here's how my "wrapper" command looks like:

#[AsCommand(name: 'queue:worker:start', description: 'Poll for jobs on specified queues and execute job when found')]
final class StartCommand extends Command
{
    protected function configure(): void
    {
        $this->addOption('queue', 'Q', InputOption::VALUE_OPTIONAL, 'The queue(s) to listen on, comma separated.', '*')
            ->addOption('blocking', 'b', InputOption::VALUE_OPTIONAL, 'Use Redis pop blocking or time interval.', true)
            ->addOption('interval', 'i', InputOption::VALUE_OPTIONAL, 'Blocking timeout/interval speed in seconds.', 10)
            ->addOption('timeout', 't', InputOption::VALUE_OPTIONAL, 'Seconds a job may run before timing out.', 60)
            ->addOption('memory', 'm', InputOption::VALUE_OPTIONAL, 'The memory limit in megabytes.', 128)
            ->addOption('pid', 'P', InputOption::VALUE_OPTIONAL, 'Absolute path to PID file, must be writeable by worker.');
    }

    protected function execute(InputInterface $input, OutputInterface $output): int
    {
        $command = new \Resque\Commands\Worker\Start();

        // Clone parameters to new input
        $input = $this->cloneResqueInput($input, $command->getDefinition());

        return $command->run($input, $output);
    }
}

So here configure method is literally copied from the Start command. Then in execute I instantiate the command I want to execute and run cloneResqueInput to make an independent input object which would not be tied to a terminal.

And the cloneResqueInput:

    protected function cloneResqueInput(InputInterface $input, InputDefinition $definition): Input
    {
        $cloned = new ArrayInput([], $definition);
        foreach ($input->getArguments() as $key => $value) {
            if ($key === 'command') {
                continue;
            }
            $cloned->setArgument($key, $value);
        }
        foreach ($input->getOptions() as $key => $value) {
            switch ($key) {
                case 'command':
                    break;
                case 'help':
                    break;
                case 'quiet':
                    break;
                case 'verbose':
                    break;
                case 'version':
                    break;
                case 'ansi':
                    break;
                case 'no-interaction':
                    break;
                default:
                    $cloned->setOption($key, $value);
            }
        }
        $cloned->setOption('config', CONFIG.'queue.yml');
        $cloned->setInteractive(false);

        return $cloned;
    }

Here I create a new Input based on the commands' InputDefinition, and transfer all arguments and options my Input has but without pre-defined Symfony parameters. And since I have the possibility I add my custom config and disable the interactive mode.

So with this "wrapper" I am finally able to start a worker via a process manager. Though this probably removes the ability for workers to listen for signals, but that's alright for me since I don't use them much. Also, I think this entire issue may be because of these signals.