TYPO3: logging

AdditionalConfiguration.php

<?php

// Don't log any deprecations
unset($GLOBALS['TYPO3_CONF_VARS']['LOG']['TYPO3']['CMS']['deprecations']);

// Log only errors and higher (default is 'warning')
$GLOBALS['TYPO3_CONF_VARS']['LOG']['writerConfiguration'] = [
	\TYPO3\CMS\Core\Log\LogLevel::ERROR => [
		\TYPO3\CMS\Core\Log\Writer\FileWriter::class => [],
	],
];

// Enable deprecation log for TYPO3 9+
$logWriterConf = [
   'TYPO3' => [
       'CMS' => [
           'deprecations' => [
               'writerConfiguration' => [
                   \TYPO3\CMS\Core\Log\LogLevel::NOTICE => [
                       \TYPO3\CMS\Core\Log\Writer\FileWriter::class => [
                           'disabled' => false,
                       ],
                   ],
               ],
           ],
       ],
   ],
];

$GLOBALS['TYPO3_CONF_VARS']['LOG'] = array_replace_recursive($GLOBALS['TYPO3_CONF_VARS']['LOG'], $logWriterConf);

ext_localconf.php

<?php

$logWriterConf = [
    // Set log config for namespace \Vendor\MyExtension\Controller
    'Vendor' => [
        'MyExtension' => [
            'Controller' => [
                'writerConfiguration' => [
                    \TYPO3\CMS\Core\Log\LogLevel::INFO => [
                        \TYPO3\CMS\Core\Log\Writer\FileWriter::class => [
                            // TYPO3 >= 9: logging to var/log/typo3_myext-controller_<md5>.log
                            'logFileInfix' => 'myext-controller'
                            // TYPO3 < 9: logging to html/typo3temp/var/logs/myext-controller.log
                            'logFile' => 'typo3temp/var/logs/myext-controller.log'
                        ],
                    ],
                ],
            ],
        ],
    ],
];
$GLOBALS['TYPO3_CONF_VARS']['LOG'] = array_replace_recursive($GLOBALS['TYPO3_CONF_VARS']['LOG'], $logWriterConf);

// Set logging for exceptions during rendering of single content elements:
$GLOBALS['TYPO3_CONF_VARS']['LOG']['TYPO3']['CMS']['Frontend']['ContentObject']['Exception']['ProductionExceptionHandler']['writerConfiguration'] = [
    \TYPO3\CMS\Core\Log\LogLevel::ERROR => [
        \TYPO3\CMS\Core\Log\Writer\FileWriter::class => [
            'logFileInfix' => 'exceptions'
        ],
    ],
];

some_class.php

<?php

// TYPO3 9+

use Psr\Log\LoggerAwareInterface;
use Psr\Log\LoggerAwareTrait;
use TYPO3\CMS\Core\Log\LogLevel;

class CleanupBeUsers extends Command implements LoggerAwareInterface
{
     use LoggerAwareTrait;
     
     function xxx()
     {
        $this->logger->log(LogLevel::INFO, $message);
     }
}

// Pre TYPO3 9

/** @var \TYPO3\CMS\Core\Log\Logger */
$this->logger = GeneralUtility::makeInstance(\TYPO3\CMS\Core\Log\LogManager::class)->getLogger(__CLASS__);
$this->logger->log(\TYPO3\CMS\Core\Log\LogLevel::ERROR, $message);