Are a WSGI server and HTTP server required to serve a Flask app?

python nginx flask uwsgi
culebrón picture culebrón · Aug 16, 2016 · Viewed 24.6k times · Source

Setting up Flask with uWSGI and Nginx is quite difficult, and even with buildout scripts it takes quite some time, and has to be recorded to instructions to be reproduced later.

If I don't plan a big load on server (it's hidden from public), does it make sense to run it without uWSGI? (Flask can listen to a port. Can Nginx just forward requests?)

Does it make sense to not use even Nginx, just running bare flask app on a port?

Answer

davidism picture davidism · Aug 16, 2016

When you "run Flask" you are actually running Werkzeug's development WSGI server, and passing your Flask app as the WSGI callable.

The development server is not intended for use in production. It is not designed to be particularly efficient, stable, or secure. It does not support all the possible features of a HTTP server.

Replace the Werkzeug dev server with a production-ready WSGI server such as Gunicorn or uWSGI when moving to production, no matter where the app will be available.

The answer is similar for "should I use a web server". WSGI servers happen to have HTTP servers but they will not be as good as a dedicated production HTTP server (Nginx, Apache, etc.).

Flask documents how to deploy in various ways. Many hosting providers also have documentation about deploying Python or Flask.

Related questions

What is the point of uWSGI?

I'm looking at the WSGI specification and I'm trying to figure out how servers like uWSGI fit into the picture. I understand the point of the WSGI spec is to separate web servers like nginx from web applications like something …

Read More
uwsgi + nginx + flask: upstream prematurely closed

I created an endpoint on my flask which generates a spreadsheet from a database query (remote db) and then sends it as a download in the browser. Flask doesn't throw any errors. Uwsgi doesn't complain. But when I check nginx's …

Read More
Flask application traceback doesn't show up in server log

I'm running my Flask application with uWSGI and nginx. There's a 500 error, but the traceback doesn't appear in the browser or the logs. How do I log the traceback from Flask? uwsgi --http-socket 127.0.0.1:9000 --wsgi-file /var/webapps/magicws/service.py --module …

Read More