refactor: Remove shutdown handler (now deprecated in FastAPI)

Author: Alan Christie

app/app.py

@@ -4,7 +4,6 @@
 import logging
 import os
 import sqlite3
-import threading
 from logging.config import dictConfig
 from typing import Any
 
@@ -87,14 +86,6 @@ def _get_location(uuid: str) -> str:
             _ES[2],
         )
 
-# The active websocket connections (and a thread lock).
-# A set of WebSocket objects appended to when a connection is made
-# and where objects are removed when each the connection is closed.
-# This is used by the "shutdown" event to gracefully close all
-# active connections.
-_ACTIVE_CONNECTIONS: set[WebSocket] = set()
-_ACTIVE_CONNECTIONS_LOCK = threading.Lock()
-
 
 # We use pydantic to declare the model (request payloads) for the internal REST API.
 # The public API is a WebSocket API and does not require a model.
@@ -125,26 +116,6 @@ class EventStreamGetResponse(BaseModel):
     event_streams: list[EventStreamItem]
 
 
-def _add_connection(websocket: WebSocket):
-    """Safely add a connection to the active connections set."""
-    with _ACTIVE_CONNECTIONS_LOCK:
-        _ACTIVE_CONNECTIONS.add(websocket)
-
-
-def _remove_connection(websocket: WebSocket):
-    """Safely remove a connection from the active connections set."""
-    with _ACTIVE_CONNECTIONS_LOCK:
-        _ACTIVE_CONNECTIONS.remove(websocket)
-
-
-@app_public.on_event("shutdown")
-async def shutdown():
-    """The application is shutting down.
-    Gracefully close all active connections."""
-    for websocket in _ACTIVE_CONNECTIONS:
-        await websocket.close(code=status.WS_1001_GOING_AWAY, reason="Server shutdown")
-
-
 # Endpoints for the 'public-facing' event-stream web-socket API ------------------------
 
 
@@ -187,13 +158,7 @@ async def event_stream(websocket: WebSocket, uuid: str):
         routing_key,
     )
     await websocket.accept()
-    # Add us to the set of active connections
-    _add_connection(websocket)
-    _LOGGER.info(
-        "Accepted connection for %s (%s active connections)",
-        es_id,
-        len(_ACTIVE_CONNECTIONS),
-    )
+    _LOGGER.info("Accepted connection for %s", es_id)
 
     _LOGGER.debug("Creating reader for %s...", es_id)
     message_reader = _get_from_queue(routing_key)
@@ -213,9 +178,6 @@ async def event_stream(websocket: WebSocket, uuid: str):
         else:
             await websocket.send_text(str(message_body))
 
-    # Remove us from the set of active connections
-    _remove_connection(websocket)
-
     _LOGGER.info("Closing %s (uuid=%s)...", es_id, uuid)
     await websocket.close(
         code=status.WS_1000_NORMAL_CLOSURE, reason="The stream has been deleted"