Added more websocket endpoints

Can now subscribe to:
- spool/filament/vendor level events, not specific to any specific ID
- root level events, captures all events sent

spoolman/api/v1/router.py

@@ -2,9 +2,10 @@
 
 # ruff: noqa: D103
 
+import asyncio
 import logging
 
-from fastapi import FastAPI
+from fastapi import FastAPI, WebSocket, WebSocketDisconnect
 from fastapi.responses import JSONResponse
 from starlette.requests import Request
 from starlette.responses import Response
@@ -12,6 +13,7 @@ from starlette.responses import Response
 from spoolman import env
 from spoolman.database.database import backup_global_db
 from spoolman.exceptions import ItemNotFoundError
+from spoolman.ws import websocket_manager
 
 from . import filament, models, other, spool, vendor
 
@@ -20,6 +22,15 @@ logger = logging.getLogger(__name__)
 app = FastAPI(
     title="Spoolman REST API v1",
     version="1.0.0",
+    description="""
+    REST API for Spoolman.
+
+    The API is served on the path `/api/v1/`.
+
+    Some endpoints also serve a websocket on the same path. The websocket is used to listen for changes to the data
+    that the endpoint serves. The websocket messages are JSON objects. Additionally, there is a root-level websocket
+    endpoint that listens for changes to any data in the database.
+    """,
 )
 
 
@@ -73,6 +84,24 @@ async def backup():  # noqa: ANN201
     return models.BackupResponse(path=str(path))
 
 
+@app.websocket(
+    "/",
+    name="Listen to any changes",
+)
+async def notify(
+    websocket: WebSocket,
+) -> None:
+    await websocket.accept()
+    websocket_manager.connect((), websocket)
+    try:
+        while True:
+            await asyncio.sleep(0.5)
+            if await websocket.receive_text():
+                await websocket.send_json({"status": "healthy"})
+    except WebSocketDisconnect:
+        websocket_manager.disconnect((), websocket)
+
+
 # Add routers
 app.include_router(filament.router)
 app.include_router(spool.router)