FastAPI + Reflex and NGINX in a production environment

[davidmuraya]

I am using Reflex to develop a frontend application for a FastAPI app.

The reason I am doing this is because the frontend will be part of larger fastapi project. I want to gradually move the existing frontend to reflex. The reflex app is sending requests to the fastapi backend via HTTPX.

I am exporting the frontend created with the reflex with the reflex export command to the directory .web/_static/
I am using fastapi to host the static files. Here is my fastapi application
fastapi-reflex/app/backend/main.py at main · davidmuraya/fastapi-reflex

On my local dev environment, everything works OK, but I am having trouble deploying the reflex backend in nginx.

My rxconfig.py

My reflex backend is working, as shown here:

Here is my nginx configuration. The HTTP traffic is for the fastapi application:
The websocket is configured as shown below. This is for the reflex backend. I followed instructions be masenf here in this Q&A:
Nginx + Certbot for Reflex app · reflex-dev · Discussion #1752

The websocket connects successfully:

But I get these errors in nginx:

2025/02/19 11:46:10 [error] 855#0: *1 connect() failed (111: Connection refused) while connecting to upstream, client: 41.90.172.221, server: demo.bima-mo.com, request: "GET /_event/?EIO=4&transport=websocket HTTP/1.1", upstream: "http://127.0.0.1:8000/_event/?EIO=4&transport=websocket", host: "demo.bima-mo.com"
2025/02/19 11:46:16 [error] 855#0: *3 connect() failed (111: Connection refused) while connecting to upstream, client: 41.90.172.221, server: demo.bima-mo.com, request: "GET /_event/?EIO=4&transport=websocket HTTP/1.1", upstream: "http://127.0.0.1:8000/_event/?EIO=4&transport=websocket", host: "demo.bima-mo.com"
2025/02/19 11:46:24 [error] 855#0: *5 connect() failed (111: Connection refused) while connecting to upstream, client: 41.90.172.221, server: demo.bima-mo.com, request: "GET /_event/?EIO=4&transport=websocket HTTP/1.1", upstream: "http://127.0.0.1:8000/_event/?EIO=4&transport=websocket", host: "demo.bima-mo.com"
2025/02/19 11:56:53 [error] 1783#0: *3 connect() failed (111: Connection refused) while connecting to upstream, client: 41.90.172.221, server: demo.bima-mo.com, request: "GET /_event/?EIO=4&transport=websocket HTTP/1.1", upstream: "http://127.0.0.1:8000/_event/?EIO=4&transport=websocket", host: "demo.bima-mo.com"

I cannot login for example – the following error is shown in my front end application:

This login for example works OK on my local dev env.

I am inclined to think I have not configured nginx correctly?

Any ideas are welcome.

[davidmuraya]

I have tried deleting this question. Please ignore it.

I had not set up the fastapi url correctly hence the "Connection Refused" error.