don't pass ceilometer options to oslo.db engine facade

oslo.db EngineFacade class only support options defined by oslo.db,
but we're passing options defined by ceilometer, so oslo.db complains
with a warning message:

NotSupportedWarning: Configuration option(s) ['alarm_connection', \
'alarm_history_time_to_live', 'db2nosql_resource_id_maxlen', \
'event_connection', 'event_time_to_live', 'metering_connection', \
'metering_time_to_live'] not supported exception.NotSupportedWarning

This patch makes sure only options defined by oslo.db will be sent
to EngineFacade

Change-Id: I2a39737a5f7824918c28ff2180f2ea95e7e82537
Closes-Bug: #1516515

ceilometer/event/storage/impl_sqlalchemy.py

@@ -27,6 +27,7 @@ import sqlalchemy as sa
 from ceilometer.event.storage import base
 from ceilometer.event.storage import models as api_models
 from ceilometer.i18n import _LE, _LI
+from ceilometer import storage
 from ceilometer.storage.sqlalchemy import models
 from ceilometer import utils
 
@@ -130,6 +131,9 @@ class Connection(base.Connection):
         # in storage.__init__.get_connection_from_config function
         options = dict(cfg.CONF.database.items())
         options['max_retries'] = 0
+        # oslo.db doesn't support options defined by Ceilometer
+        for opt in storage.OPTS:
+            options.pop(opt.name, None)
         self._engine_facade = db_session.EngineFacade(url, **options)
 
     def upgrade(self):

ceilometer/storage/impl_sqlalchemy.py

@@ -223,6 +223,9 @@ class Connection(base.Connection):
         # in storage.__init__.get_connection_from_config function
         options = dict(cfg.CONF.database.items())
         options['max_retries'] = 0
+        # oslo.db doesn't support options defined by Ceilometer
+        for opt in storage.OPTS:
+            options.pop(opt.name, None)
         self._engine_facade = db_session.EngineFacade(url, **options)
 
     def upgrade(self):

ceilometer/tests/functional/storage/test_impl_sqlalchemy.py

@@ -19,8 +19,10 @@
 """
 
 import datetime
+import warnings
 
 import mock
+from oslo_db import exception
 from oslo_utils import timeutils
 from six.moves import reprlib
 
@@ -43,6 +45,17 @@ class CeilometerBaseTest(tests_db.TestBase):
         self.assertEqual('value', base['key'])
 
 
+@tests_db.run_with('sqlite')
+class EngineFacadeTest(tests_db.TestBase):
+
+    @mock.patch.object(warnings, 'warn')
+    def test_no_not_supported_warning(self, mocked):
+        impl_sqlalchemy.Connection('sqlite://')
+        impl_sqla_event.Connection('sqlite://')
+        self.assertNotIn(mock.call(mock.ANY, exception.NotSupportedWarning),
+                         mocked.call_args_list)
+
+
 @tests_db.run_with('sqlite', 'mysql', 'pgsql')
 class EventTypeTest(tests_db.TestBase):
     # EventType is a construct specific to sqlalchemy