Remove usage of WritableLogger from oslo_log

With Eventlet 0.17.2, we can directly pass the logger instance. This
allows us to deprecate/remove the WritableLogger class from oslo.log.

Closes-Bug: #1440773
Change-Id: I3985b30b499a1e676d39c2a6cd3a31ac13c0ab47

neutron/agent/linux/utils.py

@@ -29,7 +29,6 @@ from eventlet.green import subprocess
 from eventlet import greenthread
 from oslo_config import cfg
 from oslo_log import log as logging
-from oslo_log import loggers
 from oslo_rootwrap import client
 from oslo_utils import excutils
 import six
@@ -418,4 +417,4 @@ class UnixDomainWSGIServer(wsgi.Server):
                              application,
                              max_size=self.num_threads,
                              protocol=UnixDomainHttpProtocol,
-                             log=loggers.WritableLogger(logger))
+                             log=logger)

neutron/tests/unit/test_wsgi.py

@@ -176,8 +176,7 @@ class TestWSGIServer(base.BaseTestCase):
         server.stop()
 
     @mock.patch.object(wsgi, 'eventlet')
-    @mock.patch.object(wsgi, 'loggers')
-    def test__run(self, logging_mock, eventlet_mock):
+    def test__run(self, eventlet_mock):
         server = wsgi.Server('test')
         server._run("app", "socket")
         eventlet_mock.wsgi.server.assert_called_once_with(
@@ -188,7 +187,6 @@ class TestWSGIServer(base.BaseTestCase):
             keepalive=CONF.wsgi_keep_alive,
             socket_timeout=server.client_socket_timeout
         )
-        self.assertTrue(len(logging_mock.mock_calls))
 
 
 class SerializerTest(base.BaseTestCase):

neutron/wsgi.py

@@ -29,7 +29,6 @@ import eventlet.wsgi
 from oslo_config import cfg
 import oslo_i18n
 from oslo_log import log as logging
-from oslo_log import loggers
 from oslo_serialization import jsonutils
 from oslo_service import service as common_service
 from oslo_service import systemd
@@ -288,7 +287,7 @@ class Server(object):
         """Start a WSGI server in a new green thread."""
         eventlet.wsgi.server(socket, application,
                              max_size=self.num_threads,
-                             log=loggers.WritableLogger(LOG),
+                             log=LOG,
                              keepalive=CONF.wsgi_keep_alive,
                              socket_timeout=self.client_socket_timeout)