add debug log for loki

tests/integration/test_cos.py

@@ -4,6 +4,7 @@
 """Integration tests for jenkins-k8s-operator with COS."""
 
 import functools
+import logging
 import typing
 
 import pytest
@@ -17,6 +18,8 @@
 from .helpers import wait_for
 from .types_ import UnitWebClient
 
+logger = logging.getLogger(__name__)
+
 
 @pytest.mark.abort_on_fail
 async def test_prometheus_integration(
@@ -56,6 +59,7 @@ def log_files_exist(
     """
     series = requests.get(f"http://{unit_address}:3100/loki/api/v1/series", timeout=10).json()
     log_files = set(series_data["filename"] for series_data in series["data"])
+    logger.info("Loki log files: %s", log_files)
     if not all(filename in log_files for filename in filenames):
         return False
     log_query = requests.get(