From 4e4bffc3d11aceac200026cd8228b20ff91f0426 Mon Sep 17 00:00:00 2001
From: Armando Migliaccio <armamig@gmail.com>
Date: Wed, 30 Nov 2016 20:24:35 -0800
Subject: [PATCH] Sync up bare minimum from neutron.db.api into lib

This is enough to make the lib's version of the context to work
seamlessly.

Change-Id: Ibb1e16e50b6372f4271e0925f36c0ee87b86c2cf
---
 neutron_lib/db/_api.py             | 36 +++++++-----------------------
 neutron_lib/tests/unit/db/_base.py |  2 +-
 2 files changed, 9 insertions(+), 29 deletions(-)

diff --git a/neutron_lib/db/_api.py b/neutron_lib/db/_api.py
index e681b37ba..ee1d56c1d 100644
--- a/neutron_lib/db/_api.py
+++ b/neutron_lib/db/_api.py
@@ -10,37 +10,17 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-"""
-TEMPORARY: use the old EngineFacade and lazy init.
-
-TODO(HenryG): replace this file with the new db/api.py from neutron.
-"""
-
-from oslo_config import cfg
-from oslo_db.sqlalchemy import session
-
-_FACADE = None
+from oslo_db.sqlalchemy import enginefacade
 
 
-def _create_facade_lazily():
-    global _FACADE
-
-    # NOTE: This is going to change with bug 1520719
-    if _FACADE is None:
-        _FACADE = session.EngineFacade.from_config(cfg.CONF, sqlite_fk=True)
-
-    return _FACADE
-
-
-def get_engine():
-    """Helper method to grab engine."""
-    facade = _create_facade_lazily()
-    return facade.get_engine()
+context_manager = enginefacade.transaction_context()
+context_manager.configure(sqlite_fk=True)
 
 
+# TODO(akamyshnikova): when all places in the code, which use sessions/
+# connections will be updated, this won't be needed
 def get_session(autocommit=True, expire_on_commit=False, use_slave=False):
     """Helper method to grab session."""
-    facade = _create_facade_lazily()
-    return facade.get_session(autocommit=autocommit,
-                              expire_on_commit=expire_on_commit,
-                              use_slave=use_slave)
+    return context_manager.get_legacy_facade().get_session(
+        autocommit=autocommit, expire_on_commit=expire_on_commit,
+        use_slave=use_slave)
diff --git a/neutron_lib/tests/unit/db/_base.py b/neutron_lib/tests/unit/db/_base.py
index 77ba2c329..92c041a85 100644
--- a/neutron_lib/tests/unit/db/_base.py
+++ b/neutron_lib/tests/unit/db/_base.py
@@ -30,7 +30,7 @@ class SqlFixture(fixtures.Fixture):
 
     def _setUp(self):
         # Register all data models
-        engine = db_api.get_engine()
+        engine = db_api.context_manager.get_legacy_facade().get_engine()
         if not SqlFixture._TABLES_ESTABLISHED:
             model_base.BASEV2.metadata.create_all(engine)
             SqlFixture._TABLES_ESTABLISHED = True