Summary

WebSocket is not working even though host and origin are the same.

Steps to reproduce

What are the steps we should take to reproduce the bug:

1. Deploy streamlit to any server (non-localhost)
2. Put a proxy before streamlit
3. Invoke the streamlit app from proxy server address, as such HOST and ORIGIN will be same when calling streamlit websocket

Expected behavior:

Streamlit should work.

Actual behavior:

WebSocket will not work, complaining about response code 403.

Debug info

• Streamlit version: 0.50.2
• Python version: 3.8
• Using PipEnv
• OS version:
• Browser version: Chrome 79.0.3945.117