Reduce Log Size

To reduce the testrepository.subunit output, eliminate debugging logs
from gear.Server and gear.Client.

This is handled via an ENV defined in the tox.ini called `OS_LOG_DEFAULTS`.
Any module can be specified in the typicall python logging format (e.g.
"gear.Server=INFO"). Each entry should be comma separated. For each valid
entry, a fake logger is created with the log level set to that level.

An invalid format will be skipped (expected: `<module name str>=<level_str>`).

An invalid logging level will default to logging.DEBUG.

Specifying OS_LOG_DEFAULT as an ENV var prior to running tox will override
the default values defined in tox.ini.

Change-Id: I893418435c538bfcedb803d12b57832c8111f06f

.testr.conf

@@ -1,4 +1,4 @@
 [DEFAULT]
-test_command=OS_STDOUT_CAPTURE=${OS_STDOUT_CAPTURE:-1} OS_STDERR_CAPTURE=${OS_STDERR_CAPTURE:-1} OS_LOG_CAPTURE=${OS_LOG_CAPTURE:-1} ${PYTHON:-python} -m subunit.run discover -t ./ tests $LISTOPT $IDOPTION
+test_command=OS_STDOUT_CAPTURE=${OS_STDOUT_CAPTURE:-1} OS_STDERR_CAPTURE=${OS_STDERR_CAPTURE:-1} OS_LOG_CAPTURE=${OS_LOG_CAPTURE:-1} OS_LOG_DEFAULTS=${OS_LOG_DEFAULTS:-""} ${PYTHON:-python} -m subunit.run discover -t ./ tests $LISTOPT $IDOPTION
 test_id_option=--load-list $IDFILE
 test_list_option=--list

tests/base.py

@@ -862,6 +862,28 @@ class BaseTestCase(testtools.TestCase):
                 format='%(asctime)s %(name)-32s '
                 '%(levelname)-8s %(message)s'))
 
+            # NOTE(notmorgan): Extract logging overrides for specific libraries
+            # from the OS_LOG_DEFAULTS env and create FakeLogger fixtures for
+            # each. This is used to limit the output during test runs from
+            # libraries that zuul depends on such as gear.
+            log_defaults_from_env = os.environ.get('OS_LOG_DEFAULTS')
+
+            if log_defaults_from_env:
+                for default in log_defaults_from_env.split(','):
+                    try:
+                        name, level_str = default.split('=', 1)
+                        level = getattr(logging, level_str, logging.DEBUG)
+                        self.useFixture(fixtures.FakeLogger(
+                            name=name,
+                            level=level,
+                            format='%(asctime)s %(name)-32s '
+                                   '%(levelname)-8s %(message)s'))
+                    except ValueError:
+                        # NOTE(notmorgan): Invalid format of the log default,
+                        # skip and don't try and apply a logger for the
+                        # specified module
+                        pass
+
 
 class ZuulTestCase(BaseTestCase):
 

tox.ini

@@ -9,6 +9,7 @@ setenv = STATSD_HOST=127.0.0.1
          STATSD_PORT=8125
          VIRTUAL_ENV={envdir}
          OS_TEST_TIMEOUT=30
+         OS_LOG_DEFAULTS={env:OS_LOG_DEFAULTS:gear.Server=INFO,gear.Client=INFO}
 passenv = ZUUL_TEST_ROOT
 usedevelop = True
 install_command = pip install {opts} {packages}