Heroku Flask - Deploy A 'modular' App From Tutorial Not Working, Foreman Start Works Locally

based on this structure: http://flask.pocoo.org/docs/patterns/packages/ I also tried this post: Deploying Flask app to Heroku I am having trouble getting this to work on heroku. I

Solution 1:

The app.run() was in there twice, which as you noted is what's screwing things up. The app.run() invokes a simply pure-python development server so that you can easily run and/or debug your script.

By invoking it at the module level (right under your import in runserver.py), you were effectively trying to start the development server as the python code was loaded, and then when it went to run it when invoked from the Procfile, the development server was already in flight, having been starting with it's defaults (latest version of Flask is pulling relevant defaults from the SERVER_NAME environment variable). By having it in both places, you were trying to invoke that method twice.

You basically want either the straight up module load (in which case, kill off the code under "if name ...", or you use the code when invoking under main, in which case don't start the service at module load time.