use sqla functions from neutron-lib

The public db apis are available in neutron-lib. This patch consumes
the sqla_listen, sqla_remove and sqla_remove_all functions from lib
by removing them from neutron and using lib's version.

There's also a TODO added here so we can eventually rehome the
check_no_sqlalchemy_event_import hacking check to neutron-lib.

NeutronLibImpact

Change-Id: I3b3862016125303fb227b4ff41420a89bb33c917

neutron/db/api.py

@@ -31,7 +31,6 @@ from pecan import util as p_util
 import six
 import sqlalchemy
 from sqlalchemy import event  # noqa
-from sqlalchemy import exc as sql_exc
 from sqlalchemy import orm
 from sqlalchemy.orm import exc
 
@@ -148,35 +147,6 @@ def autonested_transaction(sess):
         yield tx
 
 
-_REGISTERED_SQLA_EVENTS = []
-
-
-def sqla_listen(*args):
-    """Wrapper to track subscribers for test teardowns.
-
-    SQLAlchemy has no "unsubscribe all" option for its event listener
-    framework so we need to keep track of the subscribers by having
-    them call through here for test teardowns.
-    """
-    event.listen(*args)
-    _REGISTERED_SQLA_EVENTS.append(args)
-
-
-def sqla_remove(*args):
-    event.remove(*args)
-    _REGISTERED_SQLA_EVENTS.remove(args)
-
-
-def sqla_remove_all():
-    for args in _REGISTERED_SQLA_EVENTS:
-        try:
-            event.remove(*args)
-        except sql_exc.InvalidRequestError:
-            # already removed
-            pass
-    del _REGISTERED_SQLA_EVENTS[:]
-
-
 @event.listens_for(orm.session.Session, "after_flush")
 def add_to_rel_load_list(session, flush_context=None):
     # keep track of new items to load relationships on during commit

neutron/db/db_base_plugin_v2.py

@@ -162,12 +162,13 @@ class NeutronDbPluginV2(db_base_plugin_common.DbBasePluginCommon,
             # NOTE(arosen) These event listeners are here to hook into when
             # port status changes and notify nova about their change.
             self.nova_notifier = nova.Notifier.get_instance()
-            db_api.sqla_listen(models_v2.Port, 'after_insert',
-                               self.nova_notifier.send_port_status)
-            db_api.sqla_listen(models_v2.Port, 'after_update',
-                               self.nova_notifier.send_port_status)
-            db_api.sqla_listen(models_v2.Port.status, 'set',
-                               self.nova_notifier.record_port_status_changed)
+            lib_db_api.sqla_listen(models_v2.Port, 'after_insert',
+                                   self.nova_notifier.send_port_status)
+            lib_db_api.sqla_listen(models_v2.Port, 'after_update',
+                                   self.nova_notifier.send_port_status)
+            lib_db_api.sqla_listen(
+                models_v2.Port.status, 'set',
+                self.nova_notifier.record_port_status_changed)
 
     @registry.receives(resources.RBAC_POLICY, [events.BEFORE_CREATE,
                                                events.BEFORE_UPDATE,

neutron/hacking/checks.py

@@ -243,6 +243,7 @@ def check_python3_no_filter(logical_line):
         yield(0, msg)
 
 
+# TODO(boden): rehome this check to neutron-lib
 @flake8ext
 def check_no_sqlalchemy_event_import(logical_line, filename, noqa):
     """N346 - Use neutron.db.api.sqla_listen instead of sqlalchemy event."""
@@ -256,8 +257,8 @@ def check_no_sqlalchemy_event_import(logical_line, filename, noqa):
         if kw not in logical_line:
             return
     yield (0, "N346: Register sqlalchemy events through "
-              "neutron.db.api.sqla_listen so they can be cleaned up between "
-              "unit tests")
+              "neutron_lib.db.api.sqla_listen so they can be cleaned up "
+              "between unit tests")
 
 
 def factory(register):

neutron/quota/resource.py

@@ -12,6 +12,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from neutron_lib.db import api as lib_db_api
 from neutron_lib.plugins import constants
 from neutron_lib.plugins import directory
 from oslo_config import cfg
@@ -318,19 +319,19 @@ class TrackedResource(BaseResource):
                                self._model_class)
 
     def register_events(self):
-        listen = db_api.sqla_listen
+        listen = lib_db_api.sqla_listen
         listen(self._model_class, 'after_insert', self._db_event_handler)
         listen(self._model_class, 'after_delete', self._db_event_handler)
         listen(se.Session, 'after_bulk_delete', self._except_bulk_delete)
 
     def unregister_events(self):
         try:
-            db_api.sqla_remove(self._model_class, 'after_insert',
-                               self._db_event_handler)
-            db_api.sqla_remove(self._model_class, 'after_delete',
-                               self._db_event_handler)
-            db_api.sqla_remove(se.Session, 'after_bulk_delete',
-                               self._except_bulk_delete)
+            lib_db_api.sqla_remove(self._model_class, 'after_insert',
+                                   self._db_event_handler)
+            lib_db_api.sqla_remove(self._model_class, 'after_delete',
+                                   self._db_event_handler)
+            lib_db_api.sqla_remove(se.Session, 'after_bulk_delete',
+                                   self._except_bulk_delete)
         except sql_exc.InvalidRequestError:
             LOG.warning("No sqlalchemy event for resource %s found",
                         self.name)

neutron/services/loki/loki_plugin.py

@@ -14,8 +14,7 @@
 import random
 import time
 
-from neutron.db import api as db_api
-
+from neutron_lib.db import api as db_api
 from neutron_lib.services import base as service_base
 from oslo_db import exception as db_exc
 from oslo_log import log as logging

neutron/services/revisions/revision_plugin.py

@@ -11,6 +11,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from neutron_lib.db import api as db_api
 from neutron_lib.services import base as service_base
 from oslo_log import log as logging
 import sqlalchemy
@@ -20,7 +21,6 @@ import webob.exc
 
 from neutron._i18n import _
 from neutron.db import _resource_extend as resource_extend
-from neutron.db import api as db_api
 from neutron.db import standard_attr
 
 LOG = logging.getLogger(__name__)

neutron/services/timestamp/timestamp_db.py

@@ -12,13 +12,13 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from neutron_lib.db import api as db_api
 from neutron_lib import exceptions as n_exc
 from oslo_utils import timeutils
 from sqlalchemy.orm import session as se
 
 from neutron.db import _model_query as model_query
 from neutron.db import _resource_extend as resource_extend
-from neutron.db import api as db_api
 from neutron.db import standard_attr
 
 CHANGED_SINCE = 'changed_since'

neutron/tests/base.py

@@ -27,6 +27,7 @@ import eventlet.timeout
 import fixtures
 import mock
 from neutron_lib.callbacks import manager as registry_manager
+from neutron_lib.db import api as db_api
 from neutron_lib import fixture
 from oslo_concurrency.fixture import lockutils
 from oslo_config import cfg
@@ -49,7 +50,6 @@ from neutron.conf.agent import common as agent_config
 from neutron.db import _model_query as model_query
 from neutron.db import _resource_extend as resource_extend
 from neutron.db import agentschedulers_db
-from neutron.db import api as db_api
 from neutron import manager
 from neutron import policy
 from neutron.quota import resource_registry

neutron/tests/unit/db/test_db_base_plugin_v2.py

@@ -25,6 +25,7 @@ from neutron_lib.callbacks import exceptions
 from neutron_lib.callbacks import registry
 from neutron_lib import constants
 from neutron_lib import context
+from neutron_lib.db import api as lib_db_api
 from neutron_lib import exceptions as lib_exc
 from neutron_lib import fixture
 from neutron_lib.plugins import directory
@@ -6699,7 +6700,7 @@ class DbOperationBoundMixin(object):
             self._recorded_statements.append(str(clauseelement))
 
         engine = db_api.context_manager.writer.get_engine()
-        db_api.sqla_listen(engine, 'after_execute', _event_incrementer)
+        lib_db_api.sqla_listen(engine, 'after_execute', _event_incrementer)
 
     def _get_context(self):
         if self.admin:

neutron/tests/unit/plugins/ml2/test_plugin.py

@@ -29,6 +29,7 @@ from neutron_lib.callbacks import registry
 from neutron_lib.callbacks import resources
 from neutron_lib import constants
 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 import fixture
 from neutron_lib.plugins import constants as plugin_constants
@@ -1282,8 +1283,9 @@ class TestMl2PortsV2(test_plugin.TestPortsV2, Ml2PluginV2TestCase):
 
         listener = IPAllocationsGrenade()
         engine = db_api.context_manager.writer.get_engine()
-        db_api.sqla_listen(engine, 'before_cursor_execute', listener.execute)
-        db_api.sqla_listen(engine, 'commit', listener.commit)
+        lib_db_api.sqla_listen(engine, 'before_cursor_execute',
+                               listener.execute)
+        lib_db_api.sqla_listen(engine, 'commit', listener.commit)
         func()
         # make sure that the grenade went off during the commit
         self.assertTrue(listener.except_raised)

neutron/tests/unit/services/revisions/test_revision_plugin.py

@@ -15,6 +15,7 @@
 
 import netaddr
 from neutron_lib import context as nctx
+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
@@ -23,7 +24,6 @@ from oslo_utils import uuidutils
 from sqlalchemy.orm import session as se
 from webob import exc
 
-from neutron.db import api as db_api
 from neutron.db import models_v2
 from neutron.objects import ports as port_obj
 from neutron.tests.unit.plugins.ml2 import test_plugin