db purge: raise on missing tables

If running with invalid db config, we get no tables and
the command silently finished. Change that and raise some
suspicion instead.

Closes-bug: #2124043
Co-authored-by: Maurice Escher <maurice.escher@sap.com>
Change-Id: Ie26b05bdd13a4c54ca958056352fab04ceaa9140
Signed-off-by: Kiran Pawar <kinpaa@gmail.com>

manila/db/sqlalchemy/api.py

@@ -6437,6 +6437,11 @@ def purge_deleted_records(context, age_in_days):
 
     metadata = MetaData()
     metadata.reflect(get_engine())
+    tables = metadata.sorted_tables
+    if not tables:
+        msg = 'No tables found, check database connection'
+        raise exception.InvalidResults(msg)
+
     deleted_age = timeutils.utcnow() - datetime.timedelta(days=age_in_days)
 
     # Deleting rows in share_network_security_service_association
@@ -6451,7 +6456,7 @@ def purge_deleted_records(context, age_in_days):
         with context.session.begin_nested():
             context.session.delete(assoc)
 
-    for table in reversed(metadata.sorted_tables):
+    for table in reversed(tables):
         if 'deleted' not in table.columns.keys():
             continue
 

releasenotes/notes/bug-2124043-db-purge-raise-on-missing-tables-22eb3c30ee2ab29c.yaml

@@ -0,0 +1,6 @@
+---
+fixes:
+  - |
+    Purge DB records is fixed to raise error in case of missing or invalid
+    db config. For more details, please check
+    `launchpad bug #2124043 <https://bugs.launchpad.net/manila/+bug/2124043>`_