Deploy Python Flask App to Heroku R10 Error

Question

I’m hoping to deploy a flask app to Heroku using a free dyno and it seems to build successfully:

remote: Git submodules detected, installing:
remote: 
remote: Compressing source files... done.
remote: Building source:
remote: 
remote: -----> Python app detected
remote: -----> Installing requirements with pip
remote: 
remote: -----> Discovering process types
remote:        Procfile declares types -> web
remote: 
remote: -----> Compressing...
remote:        Done: 83.2M
remote: -----> Launching...
remote:        Released v94
remote:        https://MYAPP.herokuapp.com/ deployed to Heroku
remote: 
remote: Verifying deploy... done.

then checking the Heroku logs after accessing the URL i’m thrown this error:

2017-10-25T22:33:09.264449+00:00 heroku[web.1]: Starting process with command `python run.py runserver`
2017-10-25T22:33:15.514250+00:00 app[web.1]:  * Running on http://127.0.0.1:5000/ (Press CTRL+C to quit)
2017-10-25T22:33:15.519730+00:00 app[web.1]:  * Restarting with stat
2017-10-25T22:33:17.300082+00:00 app[web.1]:  * Debugger is active!
2017-10-25T22:33:17.305442+00:00 app[web.1]:  * Debugger pin code: 146-142-273
2017-10-25T22:34:09.286891+00:00 heroku[web.1]: Error R10 (Boot timeout) -> Web process failed to bind to $PORT within 60 seconds of launch
2017-10-25T22:34:09.286934+00:00 heroku[web.1]: Stopping process with SIGKILL
2017-10-25T22:34:09.469418+00:00 heroku[web.1]: Process exited with status 137
2017-10-25T22:34:09.484569+00:00 heroku[web.1]: State changed from starting to crashed

All others who have encountered this in various help sites solve their problem when binding to the Heroku $PORT, the same as how I do it:

#!venv/bin/python
import os
from app import app
port = int(os.environ.get('PORT', 33507))
app.run(host='0.0.0.0', port=port, debug=False)

And my Procfile:

web: python run.py runserver

Could it be that i’m running a virtual environment? Perhaps my app at 83.2M is too large? I’m kind of stuck here. Thanks in advance for your help!

Answer 1

Try changing your Procfile content like this:

web: gunicorn run:app -b "0.0.0.0:$PORT" -w 3

Where run is the name of the main application file denoting run.py