[placement] Use a non-nova log capture fixture

We want to avoid using the nova StandardLogging fixture, to limit
imports from nova, but it has two useful features that we want:

* always capture
* if the chosen log level is more than DEBUG, format DEBUG message
  anyway, but don't output

blueprint: placement-extract

Change-Id: Iadd32c731ebfb5a62308a4d5f907a69f93590935

nova/tests/functional/api/openstack/placement/base.py

@@ -19,6 +19,7 @@ from nova.api.openstack.placement import context
 from nova.api.openstack.placement import deploy
 from nova.api.openstack.placement.objects import resource_provider
 from nova.tests import fixtures
+from nova.tests.functional.api.openstack.placement.fixtures import capture
 from nova.tests.unit import policy_fixture
 
 
@@ -48,7 +49,7 @@ class TestCase(testtools.TestCase):
 
         self.useFixture(policy_fixture.PlacementPolicyFixture())
 
-        self.useFixture(fixtures.StandardLogging())
+        self.useFixture(capture.Logging())
         self.useFixture(output.CaptureOutput())
         # Filter ignorable warnings during test runs.
         self.useFixture(fixtures.WarningsFixture())

nova/tests/functional/api/openstack/placement/fixtures/capture.py

@@ -0,0 +1,59 @@
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+import logging
+
+import fixtures
+from oslotest import log
+
+
+class NullHandler(logging.Handler):
+    """custom default NullHandler to attempt to format the record.
+
+    Used in conjunction with Logging below to detect formatting errors
+    in debug logs.
+    """
+    def handle(self, record):
+        self.format(record)
+
+    def emit(self, record):
+        pass
+
+    def createLock(self):
+        self.lock = None
+
+
+class Logging(log.ConfigureLogging):
+    """A logging fixture providing two important fixtures.
+
+    One is to capture logs for later inspection.
+
+    The other is to make sure that DEBUG logs, even if not captured,
+    are formatted.
+    """
+
+    def __init__(self):
+        super(Logging, self).__init__()
+        # If level was not otherwise set, default to INFO.
+        if self.level is None:
+            self.level = logging.INFO
+        # Always capture logs, unlike the parent.
+        self.capture_logs = True
+
+    def setUp(self):
+        super(Logging, self).setUp()
+        if self.level > logging.DEBUG:
+            handler = NullHandler()
+            self.useFixture(fixtures.LogHandler(handler, nuke_handlers=False))
+            handler.setLevel(logging.DEBUG)

nova/tests/functional/api/openstack/placement/fixtures/gabbits.py

@@ -30,6 +30,7 @@ from nova.api.openstack.placement import policies
 from nova import rc_fields as fields
 from nova.tests import fixtures
 from nova.tests.functional.api.openstack.placement.db import test_base as tb
+from nova.tests.functional.api.openstack.placement.fixtures import capture
 from nova.tests.unit import policy_fixture
 from nova.tests import uuidsentinel as uuids
 
@@ -49,7 +50,7 @@ class APIFixture(fixture.GabbiFixture):
         # existing nova fixtures that do that. This captures the
         # output that happens outside individual tests (for
         # example database migrations).
-        self.standard_logging_fixture = fixtures.StandardLogging()
+        self.standard_logging_fixture = capture.Logging()
         self.standard_logging_fixture.setUp()
         self.output_stream_fixture = output.CaptureOutput()
         self.output_stream_fixture.setUp()

nova/tests/functional/api/openstack/placement/test_placement_api.py

@@ -17,7 +17,7 @@ import wsgi_intercept
 
 from gabbi import driver
 
-from nova.tests import fixtures as nova_fixtures
+from nova.tests.functional.api.openstack.placement.fixtures import capture
 # TODO(cdent): This whitespace blight will go away post extraction.
 from nova.tests.functional.api.openstack.placement.fixtures \
         import gabbits as fixtures
@@ -35,7 +35,7 @@ def load_tests(loader, tests, pattern):
     # capture, for cleaner results reporting.
     inner_fixtures = [
         output.CaptureOutput,
-        nova_fixtures.StandardLogging,
+        capture.Logging,
     ]
     return driver.build_tests(test_dir, loader, host=None,
                               test_loader_name=__name__,