fix: do not query for non-existent buckets in healthz

This yields a routing problem with reverse proxies. Now we're checking
for the configured bucket, which makes more sense anyway.

caluma/caluma_core/conftest.py

@@ -84,7 +84,7 @@ def db_broken_connection(transactional_db):
 def minio_mock_working(mocker):
     """Provide working minio mock for health checks."""
     return mocker.patch.object(
-        storage_clients.client.client, "bucket_exists", return_value=False
+        storage_clients.client.client, "bucket_exists", return_value=True
     )
 
 

caluma/caluma_core/health_checks.py

@@ -1,5 +1,4 @@
 from io import StringIO
-from uuid import uuid4
 
 from django.conf import settings
 from django.core import management
@@ -28,8 +27,11 @@ def _check_pending_migrations(db_name):
 @check
 def _check_media_storage_service():
     """Check media storage service connectivity."""
-    assert not storage_clients.client.client.bucket_exists(str(uuid4()))
-    return {"ok": True}
+    return {
+        "ok": storage_clients.client.client.bucket_exists(
+            settings.MEDIA_STORAGE_BUCKET_NAME
+        )
+    }
 
 
 def check_media_storage_service():