Replace Flask with a production-quality WSGI server

[tameware]

Flask is intended only for development and gives us these warnings:

Jun 23, 2020, 8:26:17 PM | Use a production WSGI server instead. Jun 23, 2020, 8:26:17 PM | WARNING: This is a development server. Do not use it in a production deployment.

This blog post mentions Waitress:

https://flask.palletsprojects.com/en/1.1.x/tutorial/deploy/

Here's another, gunicorn:

https://www.markusdosch.com/2019/03/how-to-deploy-a-python-flask-application-to-the-web-with-google-cloud-platform-for-free/

Here's a list of six, including the two above:

https://quintagroup.com/cms/python/web-server

GCP might have its own recommended WSGI server - I was not able to find one with a quick search.

[suokko]

I found following tutorial: https://cloud.google.com/appengine/docs/flexible/python/quickstart

Quick look indicate gunicorn would be preferred method.

I also see yaml configuration files everywhere. That indicates to me that I should switch my configuration file format yaml so we have only one configuration file format. I will do that tomorrow.