Always run Gunicorn (even when DEBUG=true) to ensure Socket.IO WebSocket (#341)

app.py

@@ -28,13 +28,10 @@ app.wsgi_app = ProxyFix(app.wsgi_app)  # type: ignore
 app.config['SEND_FILE_MAX_AGE_DEFAULT'] = 0  # Disable caching
 app.config['APPLICATION_ROOT'] = '/'
 
-# Determine async mode based on DEBUG setting
-# In production (DEBUG=False) with Gunicorn + gevent worker, use 'gevent'
-# In development (DEBUG=True) with Flask dev server, use 'threading'
-if DEBUG:
-    async_mode = 'threading'
-else:
-    async_mode = 'gevent'
+# Socket.IO async mode.
+# We run this app under Gunicorn with a gevent websocket worker (even when DEBUG=true),
+# so Socket.IO should always use gevent here.
+async_mode = 'gevent'
 
 # Initialize Flask-SocketIO with reverse proxy support
 socketio = SocketIO(

entrypoint.sh

@@ -105,18 +105,11 @@ change_ownership /tmp/cwa-book-downloader
 # Test write to all folders
 make_writable /cwa-book-ingest
 
-# Set the command to run based on DEBUG setting
-# DEBUG=true uses Flask dev server, otherwise uses gunicorn for production
-is_debug=$(echo "$DEBUG" | tr '[:upper:]' '[:lower:]')
-if [ "$is_debug" = "true" ]; then
-    command="python3 app.py"
-else
-    # Use geventwebsocket worker for SocketIO + WebSocket compatibility
-    # This special worker class handles WebSocket upgrades properly
-    # --workers 1: SocketIO requires sticky sessions, use 1 worker or configure sticky sessions
-    # -t 300: 300 second timeout for long-running requests
-    command="gunicorn --worker-class geventwebsocket.gunicorn.workers.GeventWebSocketWorker --workers 1 -t 300 -b ${FLASK_HOST:-0.0.0.0}:${FLASK_PORT:-8084} app:app"
-fi
+# Always run Gunicorn (even when DEBUG=true) to ensure Socket.IO WebSocket
+# upgrades work reliably on customer machines.
+# Map app LOG_LEVEL (often DEBUG/INFO/...) to gunicorn's --log-level (lowercase).
+gunicorn_loglevel=$([ "$DEBUG" = "true" ] && echo debug || echo "${LOG_LEVEL:-info}" | tr '[:upper:]' '[:lower:]')
+command="gunicorn --log-level ${gunicorn_loglevel} --access-logfile - --error-logfile - --worker-class geventwebsocket.gunicorn.workers.GeventWebSocketWorker --workers 1 -t 300 -b ${FLASK_HOST:-0.0.0.0}:${FLASK_PORT:-8084} app:app"
 
 # If DEBUG and not using an external bypass
 if [ "$DEBUG" = "true" ] && [ "$USING_EXTERNAL_BYPASSER" != "true" ]; then