use get reader/writer session from neutron-lib

The get_reader_session and get_writer_session functions are available
in neutron-lib. This patch consumes them by removing the functions
from neutron and using lib's instead.

NeutronLibImpact

Change-Id: I4055172799a0d9a0ceb387b6d47e421e1c270ada

neutron/db/api.py

@@ -175,16 +175,6 @@ def _is_nested_instance(e, etypes):
     return False
 
 
-def get_reader_session():
-    """Helper to get reader session"""
-    return context_manager.reader.get_sessionmaker()()
-
-
-def get_writer_session():
-    """Helper to get writer session"""
-    return context_manager.writer.get_sessionmaker()()
-
-
 @contextlib.contextmanager
 def autonested_transaction(sess):
     """This is a convenience method to not bother with 'nested' parameter."""

neutron/plugins/ml2/drivers/type_tunnel.py

@@ -20,6 +20,7 @@ import netaddr
 from neutron_lib.agent import topics
 from neutron_lib import constants as p_const
 from neutron_lib import context
+from neutron_lib.db import api as lib_db_api
 from neutron_lib import exceptions as exc
 from neutron_lib.plugins.ml2 import api
 from neutron_lib.plugins import utils as plugin_utils
@@ -348,37 +349,37 @@ class EndpointTunnelTypeDriver(ML2TunnelTypeDriver):
 
     def get_endpoint_by_host(self, host):
         LOG.debug("get_endpoint_by_host() called for host %s", host)
-        session = db_api.get_reader_session()
+        session = lib_db_api.get_reader_session()
         return (session.query(self.endpoint_model).
                 filter_by(host=host).first())
 
     def get_endpoint_by_ip(self, ip):
         LOG.debug("get_endpoint_by_ip() called for ip %s", ip)
-        session = db_api.get_reader_session()
+        session = lib_db_api.get_reader_session()
         return (session.query(self.endpoint_model).
                 filter_by(ip_address=ip).first())
 
     def delete_endpoint(self, ip):
         LOG.debug("delete_endpoint() called for ip %s", ip)
-        session = db_api.get_writer_session()
+        session = lib_db_api.get_writer_session()
         session.query(self.endpoint_model).filter_by(ip_address=ip).delete()
 
     def delete_endpoint_by_host_or_ip(self, host, ip):
         LOG.debug("delete_endpoint_by_host_or_ip() called for "
                   "host %(host)s or %(ip)s", {'host': host, 'ip': ip})
-        session = db_api.get_writer_session()
+        session = lib_db_api.get_writer_session()
         session.query(self.endpoint_model).filter(
             or_(self.endpoint_model.host == host,
                 self.endpoint_model.ip_address == ip)).delete()
 
     def _get_endpoints(self):
         LOG.debug("_get_endpoints() called")
-        session = db_api.get_reader_session()
+        session = lib_db_api.get_reader_session()
         return session.query(self.endpoint_model)
 
     def _add_endpoint(self, ip, host, **kwargs):
         LOG.debug("_add_endpoint() called for ip %s", ip)
-        session = db_api.get_writer_session()
+        session = lib_db_api.get_writer_session()
         try:
             endpoint = self.endpoint_model(ip_address=ip, host=host, **kwargs)
             endpoint.save(session)

neutron/plugins/ml2/plugin.py

@@ -33,6 +33,7 @@ from neutron_lib.callbacks import exceptions
 from neutron_lib.callbacks import registry
 from neutron_lib.callbacks import resources
 from neutron_lib import constants as const
+from neutron_lib.db import api as lib_db_api
 from neutron_lib.db import utils as db_utils
 from neutron_lib import exceptions as exc
 from neutron_lib.exceptions import allowedaddresspairs as addr_exc
@@ -663,7 +664,7 @@ class Ml2Plugin(db_base_plugin_v2.NeutronDbPluginV2,
     def _object_session_or_new_session(sql_obj):
         session = sqlalchemy.inspect(sql_obj).session
         if not session:
-            session = db_api.get_reader_session()
+            session = lib_db_api.get_reader_session()
         return session
 
     def _notify_port_updated(self, mech_context):

neutron/tests/unit/extensions/test_l3_ext_gw_mode.py

@@ -19,6 +19,7 @@ import netaddr
 from neutron_lib.api.definitions import l3 as l3_apidef
 from neutron_lib import constants
 from neutron_lib import context as nctx
+from neutron_lib.db import api as db_api
 from neutron_lib.plugins import directory
 from oslo_config import cfg
 from oslo_db import exception as db_exc
@@ -28,7 +29,6 @@ import testscenarios
 from webob import exc
 
 from neutron.common import utils
-from neutron.db import api as db_api
 from neutron.db import l3_db
 from neutron.db import l3_gwmode_db
 from neutron.db.models import l3 as l3_models

neutron/tests/unit/quota/test_resource.py

@@ -14,13 +14,13 @@
 
 import mock
 from neutron_lib import context
+from neutron_lib.db import api as db_api
 from neutron_lib.plugins import constants
 from neutron_lib.plugins import directory
 from oslo_config import cfg
 from oslo_utils import uuidutils
 import testtools
 
-from neutron.db import api as db_api
 from neutron.db.quota import api as quota_api
 from neutron.quota import resource
 from neutron.tests import base

neutron/tests/unit/services/metering/test_metering_plugin.py

@@ -15,13 +15,13 @@
 import mock
 from neutron_lib.api.definitions import metering as metering_apidef
 from neutron_lib import context
+from neutron_lib.db import api as db_api
 from neutron_lib.plugins import constants
 from neutron_lib.plugins import directory
 from oslo_utils import uuidutils
 
 from neutron.api.rpc.agentnotifiers import metering_rpc_agent_api
 from neutron.common import utils
-from neutron.db import api as db_api
 from neutron.db.metering import metering_rpc
 from neutron.extensions import l3 as ext_l3
 from neutron.extensions import metering as ext_metering