add health endpoint

src/kassandra/webhook.py

@@ -24,13 +24,19 @@ async def run_webhook(
         Run the webhook endpoint and put the alerts in the queue.
     """
 
-    async def handler(request:aiohttp.web_request.Request):
+    async def handler(request:aiohttp.web_request.Request)->aiohttp.web.Response:
         alert = await request.json()
         await alert_queue.put(alert)
         return aiohttp.web.Response()
 
+    async def health(request:aiohttp.web_request.Request)->aiohttp.web.Response:
+        return aiohttp.web.Response(text="OK")
+
     app = aiohttp.web.Application()
-    app.add_routes([aiohttp.web.post(config.endpoint, handler)])
+    app.add_routes([
+        aiohttp.web.post(config.endpoint, handler),
+        aiohttp.web.get("/health", health)
+    ])
     runner = aiohttp.web.AppRunner(app)
     await runner.setup()
     ssl_context = None