db: Don't use legacy 'Row()' methods

Resolve the following RemovedIn20Warning warnings:

  The Row.keys() method is considered legacy as of the 1.x series of
  SQLAlchemy and will be removed in 2.0. Use the namedtuple standard
  accessor Row._fields, or for full mapping behavior use
  row._mapping.keys()

An additional warning that appears to have been resolved in the interim
is also removed.

Change-Id: I0c33130a745b986f1bcd2ec177f78e3bb68d2271
Signed-off-by: Stephen Finucane <[email protected]>

Author: stephenfin

nova/db/main/api.py

@@ -600,7 +600,7 @@ def _compute_node_fetchall(context, filters=None, limit=None, marker=None):
     results = conn.execute(select).fetchall()
 
     # Callers expect dict-like objects, not SQLAlchemy RowProxy objects...
-    results = [dict(r) for r in results]
+    results = [dict(r._mapping) for r in results]
     conn.close()
     return results
 

nova/tests/fixtures/nova.py

@@ -865,18 +865,6 @@ def setUp(self):
             message=r'The Column.copy\(\) method is deprecated .*',
             category=sqla_exc.SADeprecationWarning)
 
-        warnings.filterwarnings(
-            'ignore',
-            module='nova',
-            message=r'The Row.keys\(\) method is considered legacy .*',
-            category=sqla_exc.SADeprecationWarning)
-
-        warnings.filterwarnings(
-            'ignore',
-            module='nova',
-            message=r'Using non-integer/slice indices on Row is deprecated .*',
-            category=sqla_exc.SADeprecationWarning)
-
         warnings.filterwarnings(
             'ignore',
             module='nova',