Code review comment for lp:~roadmr/canonical-identity-provider/charm-fix-talisker-logfile-migration

More context and discoveries and next steps from a call with Simon today:

1. We can remove the migration tasks now since they were added with different constraints in place for the planned move to talisker in the past. Since for now, we're not really need to touch Django logging, we can let it log to the same file it does now.

2. We should be able to just switch to talisker.gunicorn right now:

2a. gunicorn access logs configured to log to a file (via wsgi_access_logfile) should be still logged there in the same format.

2b. gunicorn's errorlog (wsgi_error_logfile) will be ignored by talisker. It will warn about this and will log all talisker/gunicorn logs to stderr (these include access logs in talisker's format).

2c. The above stderr logs will be retained by journald setup (but possibly not permanently) and next steps should be ideally to sort this out and move to relying on these talisker logs that should contain everything we need (and disable django logging https://talisker.readthedocs.io/en/latest/django.html#logging)