link alertmanager client to prometheus metrics

matrix_alertbot/alertmanager.py

@@ -6,6 +6,7 @@ from typing import Any, Dict, List
 import aiohttp
 import pytimeparse
 from aiohttp import ClientError
+from aiohttp_prometheus_exporter.trace import PrometheusTraceConfig
 from diskcache import Cache
 
 from matrix_alertbot.errors import (
@@ -19,7 +20,7 @@ class AlertmanagerClient:
     def __init__(self, url: str, cache: Cache) -> None:
         self.api_url = f"{url}/api/v2"
         self.cache = cache
-        self.session = aiohttp.ClientSession()
+        self.session = aiohttp.ClientSession(trace_configs=[PrometheusTraceConfig()])
 
     async def close(self) -> None:
         await self.session.close()