Flask app dont start on heroku server

Question

I\'m trying to deploy a Flask app with Heroku. It\'s simple API. Works great local with foreman but I get error (log is below) when starts on heroku.

This is my app code

Answer 1

1.Procfile should be without any extension.

2.Content of Procfile should be: web: gunicorn app:app --preload

Note:usually --preload is used when the size is more.

Answer 2

Is there actually a running dyno called web? It looks like you might have forgotten to scale your web dyno:

Add an entry like this in your Procfile:

heroku ps:scale web=1

You can use

heroku ps

to confirm that your web dyno is running.