MonoLog log file truncation method.

Logger.php

<?php

namespace \App\Logger;

class Logger extends \Monolog\Logger
{
    const MAX_SIZE = 2097152;

    /**
     * Truncates the log file per iteration.
     */
    public function truncate()
    {
        /** @var \App\Logger\Handler $handlers */
        $handlers = $this->getHandlers()['system'];

        $path = $handlers->getUrl();

        try {
            $file = new \SplFileObject($path, 'c');

            if ($file->getSize() >= self::MAX_SIZE) {
                $file->ftruncate(0);
                $file->rewind();
                echo 'Truncated ' . $file->getBasename() . PHP_EOL;
                $file = null;
            }
        } catch (\Exception $e) {
            // Silence
        }
    }
}