在没有前端的情况下在Heroku上使用Flask部署Python socket.io应用

Question

I have a Python socket app build in Flask which is to be hosted on Heroku. Now, I know that I can connect the Flask app through the client end socket which I have built in Javascript. The UI is also embedded with the client end. I wish to deploy the Flask app without any frontend/UI HTML file but it outputs the following error:

00:19:45 web.1 | 2018-06-27 00:19:45 [12308] [ERROR] Connection in use: ('0.0.0.0', 5000)

00:19:45 web.1 | 2018-06-27 00:19:45 [12308] [ERROR] Retrying in 1 second.

00:19:46 web.1 | 2018-06-27 00:19:46 [12308] [ERROR] Connection in use: ('0.0.0.0', 5000)

00:19:46 web.1 | 2018-06-27 00:19:46 [12308] [ERROR] Retrying in 1 second.

Answer 1

You need to use the bellow line in your Procfile:

web: gunicorn --worker-class eventlet -w 1 module:app

More informations about Gunicorn Web Server on: https://flask-socketio.readthedocs.io/en/latest/#gunicorn-web-server

Obs.: You need to install eventlet.