i18n - Make string translatable

Since internationalization should be enabled in Watcher, this
patchset refactors the Watcher codebase to wrap previously
untranslatable strings with i18n translation functions so we can
import them for translation into the .pot template file.

Partially Implements: blueprint support-translation
Change-Id: I425967a60b5a7957f753894e5d2ba0d2c5009d1d

watcher/common/messaging/messaging_handler.py

@@ -15,14 +15,15 @@
 # limitations under the License.
 
 import socket
+import threading
 
 import eventlet
 from oslo_config import cfg
 from oslo_log import log
 import oslo_messaging as om
-from threading import Thread
-from watcher.common.rpc import JsonPayloadSerializer
-from watcher.common.rpc import RequestContextSerializer
+
+from watcher.common import rpc
+from watcher._i18n import _LE, _LW
 
 # NOTE:
 # Ubuntu 14.04 forces librabbitmq when kombu is used
@@ -35,7 +36,7 @@ LOG = log.getLogger(__name__)
 CONF = cfg.CONF
 
 
-class MessagingHandler(Thread):
+class MessagingHandler(threading.Thread):
 
     def __init__(self, publisher_id, topic_watcher, endpoint, version,
                  serializer=None):
@@ -67,7 +68,7 @@ class MessagingHandler(Thread):
         return self.__transport
 
     def build_notifier(self):
-        serializer = RequestContextSerializer(JsonPayloadSerializer())
+        serializer = rpc.RequestContextSerializer(rpc.JsonPayloadSerializer())
         return om.Notifier(
             self.__transport,
             publisher_id=self.publisher_id,
@@ -93,11 +94,11 @@ class MessagingHandler(Thread):
                 )
                 self.__server = self.build_server(target)
             else:
-                LOG.warn("you have no defined endpoint, "
-                         "so you can only publish events")
+                LOG.warn(
+                    _LW("No endpoint defined; can only publish events"))
         except Exception as e:
             LOG.exception(e)
-            LOG.error("configure : %s" % str(e.message))
+            LOG.error(_LE("Messaging configuration error"))
 
     def run(self):
         LOG.debug("configure MessagingHandler for %s" % self.topic_watcher)
@@ -107,7 +108,7 @@ class MessagingHandler(Thread):
             self.__server.start()
 
     def stop(self):
-        LOG.debug('Stop up server')
+        LOG.debug('Stopped server')
         self.__server.wait()
         self.__server.stop()