Split Log Levels Between Stdout and Stderr With Laravel

Laravel's logging system can be configured to log specific levels in different channels. The level config option can be used to specify the minimum level to log, but this approach has limitations. To log specific levels in different channels, Monolog's FilterHandler can be used. This handler only lets records of a given level through the wrapped handler. In Laravel, the FilterHandler can be configured in the logging.php configuration file. The handler can be used to split logs between stdout and stderr channels. For example, the stdout channel can be configured to log debug and info logs, while the stderr channel can be configured to log notice and above logs. The FilterHandler can be configured using the minLevelOrList and maxLevel parameters. The minLevelOrList parameter can be used to specify a single level or a list of levels. The maxLevel parameter can be used to specify the maximum level. The logging.php configuration file can be updated to use the FilterHandler. The stdout and stderr channels can be configured to use the FilterHandler. The stdout channel can be configured to log debug and info logs, while the stderr channel can be configured to log notice and above logs. The environment settings can be used to configure the logging channels. For example, the LOG_CHANNEL, LOG_LEVEL, LOG_STACK, LOG_STDOUT_FORMATTER, and LOG_STDERR_FORMATTER environment variables can be used to configure the logging channels. Monolog has many handlers, formatters, and processors available that can be configured in Laravel. The common use-cases are already covered in the logging.php configuration file. The official Laravel documentation provides more information on logging in Laravel applications.