Django Channels WebSocket Connection Issue in Docker

Based on your configuration and the "connection refused" error you're experiencing in your Docker environment, there are several potential issues to address:

1. Port Publishing in Docker

The most common cause of "connection refused" errors in Docker is that the container's ports aren't properly published to the host machine. WebSocket connections need the appropriate port to be exposed.

BASHCopied
# Make sure you're publishing the port your WebSocket server is using
docker run --publish 8000:8000 your-image-name

2. ALLOWED_HOSTS Configuration

Your ALLOWED_HOSTS setting has an issue - WebSocket URLs should not be included in this setting:

PYTHONCopied
# Incorrect
ALLOWED_HOSTS=192.168.108.76,ws://192.168.108.76

# Correct
ALLOWED_HOSTS=['192.168.108.76']

3. Missing AllowedHostsOriginValidator

You've commented out the AllowedHostsOriginValidator, which is important for security and proper WebSocket connections:

PYTHONCopied
# Uncomment and use this in your application configuration
from channels.security.websocket import AllowedHostsOriginValidator

application = ProtocolTypeRouter({
    "http": get_asgi_application(),
    "websocket": AllowedHostsOriginValidator(
        URLRouter(channel.urls.websocket_urlpatterns)
    )
})

4. WebSocket URL Configuration

Ensure your client is connecting to the correct WebSocket URL. In a Docker environment, this might be different from your local setup:

JAVASCRIPTCopied
// Client-side example
const socket = new WebSocket('ws://192.168.108.76:8000/your-websocket-path/');

5. ASGI Server Configuration

Make sure you're running Daphne or another ASGI server that supports WebSockets:

BASHCopied
# Example Daphne command
daphne -b 0.0.0.0 -p 8000 sewts_jupiter_cloud_backend.asgi:application

The -b 0.0.0.0 is crucial as it binds to all network interfaces, allowing external connections to your container.

6. Docker Network Configuration

Check if there are any network-related issues in your Docker setup:

BASHCopied
# Inspect your Docker network
docker network inspect your-network-name

Troubleshooting Steps

1. Check Docker logs for any error messages
2. Verify the WebSocket server is running on the expected port inside the container
3. Test with a simple WebSocket client from inside the container
4. Ensure your firewall or network configuration allows WebSocket connections

Remember that the Django development server (runserver) is not suitable for production use with WebSockets. Use Daphne or another production-ready ASGI server instead.