Deploying Flask with Heroku

Question

I'm trying to deploy a Flask app to Heroku however upon pushing the code I get the error

2013-06-23T11:23:59.264600+00:00 heroku[web.1]: Error R10 (Boot timeout) -> Web process failed to bind to $PORT within 60 seconds of launch  

I'm not sure what to try, I've tried changing the port from 5000 to 33507, but to no avail. My Procfile looks like this:

web: python main.py  

main.py is the main Flask file which initiates the server.

Thanks.

Answer 1

In my Flask app hosted on Heroku, I use this code to start the server:

if __name__ == '__main__':     # Bind to PORT if defined, otherwise default to 5000.     port = int(os.environ.get('PORT', 5000))     app.run(host='0.0.0.0', port=port) 

When developing locally, this will use port 5000, in production Heroku will set the PORT environment variable.

(Side note: By default, Flask is only accessible from your own computer, not from any other in the network (see the Quickstart). Setting host='0.0.0.0' will make Flask available from the network)

Answer 2

In addition to msiemens's answer

import os from run import app as application if __name__ == '__main__':     port = int(os.environ.get('PORT', 5000))     application.run(host='0.0.0.0', port=port) 

Your Procfile should specify the port address which in this case is stored in the heroku environment variable ${PORT}

web: gunicorn --bind 0.0.0.0:${PORT} wsgi