Validate dictionaries passed to dictConfig

[adamchainz]

Description

Calls to logging.config.dictConfig should follow a schema defined in the docs: https://docs.python.org/3/library/logging.config.html#dictionary-schema-details

Perhaps this plugin can do some fast-and-cheap validation against this schema to prevent common issues, such as missing the version key.

Django’s LOGGING setting is also passed to dictConfig, if LOGGING_CONFIG is unchanged, so we may be able to validate that too.

[adamchainz]

Potential checks:

1. version required, set to 1
2. Bad capitalization of keys, like “Formatters” instead of “formatters”.
3. Typos in key names, like “formatter” instead of “formatters”. (using difflib.get_close_matches)
4. If incremental is True, formatters and filters are ignored.
5. logger.handlers referring to nonexistent handlers.
6. handlers.filters referring to nonexistent filters.
7. logger.level not being in defined names: INFO, WARNING, etc. Use get_close_matches again?