Magento 2 Custom Logger via di.xml Virtual Types

Give any class its own dedicated log file without creating a real PHP Logger class — everything is wired through XML virtual types.

How it works

Magento's DI container supports virtual types: named aliases for existing classes with different constructor arguments. Two virtual types are needed:

1. Handler — extends Magento\Framework\Logger\Handler\Base, sets fileName
2. Logger — extends Magento\Framework\Logger\Monolog, references the handler

etc/di.xml snippet