Running flask as package in production

Question

I am trying to deploy my flask app. Usually I would have an app.py and put all code in it.

app.py
templates/
|
|--index.html

for my really small projects. But then I have a slightly larger app and follow the larger app guide by flask. So I have this:

setup.py
app/
    __init__.py
    views.py
    models.py
    forms.py
    templates/
    | ---index.html

I now have all my routes and views in views.py and running the app in __init__.py:

from flask import Flask
app = Flask(__name__)
import app.views # Name in setup.py
if __name__ == "__main__":
    app.run()

(This is just an example) So now I follow the guide by running it with pip install -e . and running with: >set FLASK_APP=app(name I set in setup.py) flask run and it works. Except I do not know how to run it with one command. Since there is no one file to run I can not use gunicorn or anything like that. I am not sure how to go about executing this app. How would I run pip install . on the cloud server heroku? My problem is because I have to import the app from __init__.py and views using import blog.[insert import] (models, views etc.) Any help is appreciated. Thank you.

EDIT: I do not want to use blueprints though. That might be too much. My app is medium, not small but not large either

Answer 1

You absolutely can use Gunicorn to run this project. Gunicorn is not limited to a single file, it imports Python modules just the same as flask run can. Gunicorn just needs to know the module to import, an the WSGI object to call within that module.

When you use FLASK_APP, all that flask run does is look for module.app, module.application or instances of the Flask() class. It also supports a create_app() or make_app() app factory, but you are not using such a factory.

Gunicorn won't search, if you only give it a module, it'll expect the name application to be the WSGI callable. In your case, you are using app so all you have to do is explicitly tell it what name to use:

gunicorn app:app

The part before the : is the module to import (app in your case), the part after the colon is the callable object (also named app in your module).

If you have set FLASK_APP as a Heroku config var and want to re-use that, you can reference that on the command line for gunicorn:

gunicorn $FLASK_APP:app