use app.name as app.logger name

[davidism]

#2436 greatly simplified how logging is set up in Flask. Part of that removed the LOGGER_NAME config and hard-coded "flask.app". However, #2866 points out that due to this it is no longer possible to distinguish logs when dispatching multiple apps.

This partially reverts the logger name behavior change from 1.0. There is still no config, but the logger's name is now the same as app.name (basically the value passed to Flask(import_name)).

The information that's currently logged does make sense as coming from the user's project rather than Flask itself, although we may introduce the "flask.app" logger again in the future for logging things truly internal to Flask and not the user's app.

This may require projects to update their logging config to reference their app's name instead of "flask.app".

Closes #2866

[davidism]

I need to log in to pocoo and disable the old site. The docs are at https://flask.palletsprojects.com/logging/.

[jab]

Oh awesome! 🎉
I guess we need to get redirects set up too - let me know if I can help!