Gunicorn ImportError: cannot import name ‘ALREADY_HANDLED’ from ‘eventlet.wsgi’ in docker

Installing older version of eventlet solved the problem: pip install eventlet==0.30.2

EDIT:

you can use the newer versions like this:
pip install eventlet==0.33.0 https://github.com/benoitc/gunicorn/archive/refs/heads/master.zip#egg=gunicorn==20.1.0

see: https://github.com/benoitc/gunicorn/pull/2581#issuecomment-994198667

thank you @jmunsch