Comment 5 for bug 1955676

I think the valid fix here would be to introduce `gnocchi_incoming_driver` variable, that will allow to install dependencies based on that.
This would require implementation of configuration for extra drivers, like s3 or redis for your usecase, but eventually if you would set `gnocchi_incoming_driver: redis`, this would install all required packges for that.

Until it's implemented I'd suggest overriding `gnocchi_pip_package_extras`, for example:

  gnocchi_pip_package_extras:
    - keystone
    - mysql
    - "{{ gnocchi_storage_driver_pip_extra }}"
    - redis

This will be passed to gnocchi setup.py, which handles dependencies:
https://github.com/gnocchixyz/gnocchi/blob/master/setup.cfg#L71

And you can use config overrides for actual incoming driver configuration