the dumbest image gallery possible

see https://gitlab.com/cinnaboot/ansible_roles/-/blob/master/roles/gallery/tasks/main.yml for an ansible role

or create a python virtual environment:
$ virtualenv venv
$ source venv/bin/activate
(venv) $ pip install -r requirements.txt

then start a local flask development server:
(venv) $ export FLASK_APP=gallery
(venv) $ export FLASK_ENV=development
(venv) $ flask run

Make album folders under 'instance/images', and copy some images.