Copy unit tests for StandardLogging fixture from Nova

This comes from commit f96ec4411ce89606cf52211061003c14306dcfa1
in Nova by Sean Dague <sean@dague.net>.

The StandardLogging fixture was already merged into Cinder,
this adds the unit tests that were missed when copying over
the fixture.

Change-Id: I2fbe25ec71138e4b96ff175af72a2a56c1c8f52a
Related-Bug: #1551325

cinder/tests/unit/test_fixtures.py

@@ -0,0 +1,59 @@
+# Copyright 2010 United States Government as represented by the
+# Administrator of the National Aeronautics and Space Administration.
+# 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 fixtures as fx
+from oslo_log import log as logging
+import testtools
+
+from cinder.tests import fixtures
+
+
+class TestLogging(testtools.TestCase):
+    def test_default_logging(self):
+        stdlog = self.useFixture(fixtures.StandardLogging())
+        root = logging.getLogger()
+        # there should be a null handler as well at DEBUG
+        self.assertEqual(2, len(root.handlers), root.handlers)
+        log = logging.getLogger(__name__)
+        log.info("at info")
+        log.debug("at debug")
+        self.assertIn("at info", stdlog.logger.output)
+        self.assertNotIn("at debug", stdlog.logger.output)
+
+        # broken debug messages should still explode, even though we
+        # aren't logging them in the regular handler
+        self.assertRaises(TypeError, log.debug, "this is broken %s %s", "foo")
+
+        # and, ensure that one of the terrible log messages isn't
+        # output at info
+        warn_log = logging.getLogger('migrate.versioning.api')
+        warn_log.info("warn_log at info, should be skipped")
+        warn_log.error("warn_log at error")
+        self.assertIn("warn_log at error", stdlog.logger.output)
+        self.assertNotIn("warn_log at info", stdlog.logger.output)
+
+    def test_debug_logging(self):
+        self.useFixture(fx.EnvironmentVariable('OS_DEBUG', '1'))
+
+        stdlog = self.useFixture(fixtures.StandardLogging())
+        root = logging.getLogger()
+        # there should no longer be a null handler
+        self.assertEqual(1, len(root.handlers), root.handlers)
+        log = logging.getLogger(__name__)
+        log.info("at info")
+        log.debug("at debug")
+        self.assertIn("at info", stdlog.logger.output)
+        self.assertIn("at debug", stdlog.logger.output)