Use a registry to configure reporting handlers.

Also ensure that the LogHandler is registered by default.

Change-Id: Ib9e306a0aa45ab6f5c9b543782b5dd7019b72cf1

cloudinit/reporting.py

@@ -12,6 +12,8 @@ report events in a structured manner.
 import abc
 import logging
 
+from cloudinit.registry import DictRegistry
+
 
 FINISH_EVENT_TYPE = 'finish'
 START_EVENT_TYPE = 'start'
@@ -63,7 +65,8 @@ class LogHandler(ReportingHandler):
         logger.info(event.as_string())
 
 
-HANDLERS = [LogHandler()]
+handler_registry = DictRegistry()
+handler_registry.register_item('_logging', LogHandler())
 
 
 def report_event(event):
@@ -76,7 +79,7 @@ def report_event(event):
         The type of the event; this should be a constant from the
         reporting module.
     """
-    for handler in HANDLERS:
+    for _, handler in handler_registry.registered_items.items():
         handler.publish_event(event)
 
 

cloudinit/tests/test_reporting.py

@@ -10,17 +10,22 @@ from cloudinit.tests import TestCase
 from cloudinit.tests.util import mock
 
 
+def _fake_registry():
+    return mock.Mock(registered_items={'a': mock.MagicMock(),
+                                       'b': mock.MagicMock()})
+
+
 class TestReportStartEvent(unittest.TestCase):
 
-    @mock.patch('cloudinit.reporting.HANDLERS',
+    @mock.patch('cloudinit.reporting.handler_registry',
-                new_callable=lambda: [mock.MagicMock(), mock.MagicMock()])
+                new_callable=_fake_registry)
     def test_report_start_event_passes_something_with_as_string_to_handlers(
-            self, HANDLERS):
+            self, handler_registry):
         event_name, event_description = 'my_test_event', 'my description'
         reporting.report_start_event(event_name, event_description)
         expected_string_representation = ': '.join(
             ['start', event_name, event_description])
-        for handler in HANDLERS:
+        for _, handler in handler_registry.registered_items.items():
             self.assertEqual(1, handler.publish_event.call_count)
             event = handler.publish_event.call_args[0][0]
             self.assertEqual(expected_string_representation, event.as_string())
@@ -36,42 +41,42 @@ class TestReportFinishEvent(unittest.TestCase):
 
     def assertHandlersPassedObjectWithAsString(
             self, handlers, expected_as_string):
-        for handler in handlers:
+        for _, handler in handlers.items():
             self.assertEqual(1, handler.publish_event.call_count)
             event = handler.publish_event.call_args[0][0]
             self.assertEqual(expected_as_string, event.as_string())
 
-    @mock.patch('cloudinit.reporting.HANDLERS',
+    @mock.patch('cloudinit.reporting.handler_registry',
-                new_callable=lambda: [mock.MagicMock(), mock.MagicMock()])
+                new_callable=_fake_registry)
     def test_report_finish_event_passes_something_with_as_string_to_handlers(
-            self, HANDLERS):
+            self, handler_registry):
         event_name, event_description = self._report_finish_event()
         expected_string_representation = ': '.join(
             ['finish', event_name, event_description])
         self.assertHandlersPassedObjectWithAsString(
-            HANDLERS, expected_string_representation)
+            handler_registry.registered_items, expected_string_representation)
 
-    @mock.patch('cloudinit.reporting.HANDLERS',
+    @mock.patch('cloudinit.reporting.handler_registry',
-                new_callable=lambda: [mock.MagicMock(), mock.MagicMock()])
+                new_callable=_fake_registry)
-    def test_reporting_successful_finish_has_sensible_string_repr(self,
+    def test_reporting_successful_finish_has_sensible_string_repr(
-                                                                  HANDLERS):
+            self, handler_registry):
         event_name, event_description = self._report_finish_event(
             successful=True)
         expected_string_representation = ': '.join(
             ['finish', event_name, 'success', event_description])
         self.assertHandlersPassedObjectWithAsString(
-            HANDLERS, expected_string_representation)
+            handler_registry.registered_items, expected_string_representation)
 
-    @mock.patch('cloudinit.reporting.HANDLERS',
+    @mock.patch('cloudinit.reporting.handler_registry',
-                new_callable=lambda: [mock.MagicMock(), mock.MagicMock()])
+                new_callable=_fake_registry)
-    def test_reporting_unsuccessful_finish_has_sensible_string_repr(self,
+    def test_reporting_unsuccessful_finish_has_sensible_string_repr(
-                                                                    HANDLERS):
+            self, handler_registry):
         event_name, event_description = self._report_finish_event(
             successful=False)
         expected_string_representation = ': '.join(
             ['finish', event_name, 'fail', event_description])
         self.assertHandlersPassedObjectWithAsString(
-            HANDLERS, expected_string_representation)
+            handler_registry.registered_items, expected_string_representation)
 
 
 class TestReportingEvent(unittest.TestCase):
@@ -115,3 +120,13 @@ class TestLogHandler(TestCase):
         reporting.LogHandler().publish_event(event)
         self.assertIn(event.as_string(),
                       getLogger.return_value.info.call_args[0][0])
+
+
+class TestDefaultRegisteredHandler(TestCase):
+
+    def test_log_handler_registered_by_default(self):
+        for _, item in reporting.handler_registry.registered_items.items():
+            if isinstance(item, reporting.LogHandler):
+                break
+        else:
+            self.fail('No reporting LogHandler registered by default.')