improve session handling of dnsdomain_list

improve session handling of dnsdomain_list
and add unit tests for this method

Change-Id: I45e0e9df19ddfbafbcfde425255587d5ba530092

2 files changed, 6 insertions, 9 deletions

diff --git a/nova/db/sqlalchemy/api.py b/nova/db/sqlalchemy/api.py
index 63ef26a0e..74e6d7b3b 100644
--- a/nova/db/sqlalchemy/api.py
+++ b/nova/db/sqlalchemy/api.py
@@ -962,15 +962,8 @@ def dnsdomain_unregister(context, fqdomain):
 
 @require_context
 def dnsdomain_list(context):
-    session = get_session()
-    records = model_query(context, models.DNSDomain,
-                  session=session, read_deleted="no").\
-                  all()
-    domains = []
-    for record in records:
-        domains.append(record.domain)
-
-    return domains
+    query = model_query(context, models.DNSDomain, read_deleted="no")
+    return [row.domain for row in query.all()]
 
 
 ###################
diff --git a/nova/tests/test_db_api.py b/nova/tests/test_db_api.py
index fb277bcb8..d57ec8564 100644
--- a/nova/tests/test_db_api.py
+++ b/nova/tests/test_db_api.py
@@ -382,6 +382,10 @@ class DbApiTestCase(test.TestCase):
         self.assertEqual(project, self.project_id)
         self.assertEqual(scope, 'public')
 
+        expected = [domain1, domain2]
+        domains = db.dnsdomain_list(ctxt)
+        self.assertEqual(expected, domains)
+
         db.dnsdomain_unregister(ctxt, domain1)
         db.dnsdomain_unregister(ctxt, domain2)