Implemented base + moved plugins & service conf

In this changeset, I implemented the main logic although this is
mainly a shameful copy/paste of Nova's blueprint
https://blueprints.launchpad.net/nova/+spec/centralize-config-options

Partially Implements: blueprint centralise-config-opts

Change-Id: Ib645ad5da5c706336bb6ac37e85b027d05665c32

watcher/tests/conf/test_list_opts.py

@@ -0,0 +1,146 @@
+# -*- encoding: utf-8 -*-
+# Copyright (c) 2015 b<>com
+#
+# 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 mock
+from stevedore import extension
+
+from watcher.conf import opts
+from watcher.conf import plugins
+from watcher.tests import base
+from watcher.tests.decision_engine import fake_strategies
+
+
+class TestListOpts(base.TestCase):
+    def setUp(self):
+        super(TestListOpts, self).setUp()
+        self.base_sections = [
+            'DEFAULT', 'api', 'database', 'watcher_decision_engine',
+            'watcher_applier', 'watcher_planner', 'nova_client',
+            'glance_client', 'cinder_client', 'ceilometer_client',
+            'neutron_client', 'watcher_clients_auth']
+        self.opt_sections = list(dict(opts.list_opts()).keys())
+
+    def test_run_list_opts(self):
+        expected_sections = self.opt_sections
+
+        result = opts.list_opts()
+
+        self.assertIsNotNone(result)
+        for section_name, options in result:
+            self.assertIn(section_name, expected_sections)
+            self.assertTrue(len(options))
+
+    def test_list_opts_no_opts(self):
+        expected_sections = self.base_sections
+        # Set up the fake Stevedore extensions
+        fake_extmanager_call = extension.ExtensionManager.make_test_instance(
+            extensions=[extension.Extension(
+                name=fake_strategies.FakeDummy1Strategy2.get_name(),
+                entry_point="%s:%s" % (
+                    fake_strategies.FakeDummy1Strategy2.__module__,
+                    fake_strategies.FakeDummy1Strategy2.__name__),
+                plugin=fake_strategies.FakeDummy1Strategy2,
+                obj=None,
+            )],
+            namespace="watcher_strategies",
+        )
+
+        def m_list_available(namespace):
+            if namespace == "watcher_strategies":
+                return fake_extmanager_call
+            else:
+                return extension.ExtensionManager.make_test_instance(
+                    extensions=[], namespace=namespace)
+
+        with mock.patch.object(extension, "ExtensionManager") as m_ext_manager:
+            m_ext_manager.side_effect = m_list_available
+            result = opts.list_opts()
+
+        self.assertIsNotNone(result)
+        for section_name, options in result:
+            self.assertIn(section_name, expected_sections)
+            self.assertTrue(len(options))
+
+    def test_list_opts_with_opts(self):
+        expected_sections = self.base_sections + [
+            'watcher_strategies.strategy_1']
+        # Set up the fake Stevedore extensions
+        fake_extmanager_call = extension.ExtensionManager.make_test_instance(
+            extensions=[extension.Extension(
+                name=fake_strategies.FakeDummy1Strategy1.get_name(),
+                entry_point="%s:%s" % (
+                    fake_strategies.FakeDummy1Strategy1.__module__,
+                    fake_strategies.FakeDummy1Strategy1.__name__),
+                plugin=fake_strategies.FakeDummy1Strategy1,
+                obj=None,
+            )],
+            namespace="watcher_strategies",
+        )
+
+        def m_list_available(namespace):
+            if namespace == "watcher_strategies":
+                return fake_extmanager_call
+            else:
+                return extension.ExtensionManager.make_test_instance(
+                    extensions=[], namespace=namespace)
+
+        with mock.patch.object(extension, "ExtensionManager") as m_ext_manager:
+            m_ext_manager.side_effect = m_list_available
+            result = opts.list_opts()
+
+        self.assertIsNotNone(result)
+        for section_name, options in result:
+            self.assertIn(section_name, expected_sections)
+            self.assertTrue(len(options))
+
+        result_map = dict(result)
+        strategy_opts = result_map['watcher_strategies.strategy_1']
+        self.assertEqual(['test_opt'], [opt.name for opt in strategy_opts])
+
+
+class TestPlugins(base.TestCase):
+
+    def test_show_plugins(self):
+        # Set up the fake Stevedore extensions
+        fake_extmanager_call = extension.ExtensionManager.make_test_instance(
+            extensions=[extension.Extension(
+                name=fake_strategies.FakeDummy1Strategy1.get_name(),
+                entry_point="%s:%s" % (
+                    fake_strategies.FakeDummy1Strategy1.__module__,
+                    fake_strategies.FakeDummy1Strategy1.__name__),
+                plugin=fake_strategies.FakeDummy1Strategy1,
+                obj=None,
+            )],
+            namespace="watcher_strategies",
+        )
+
+        def m_list_available(namespace):
+            if namespace == "watcher_strategies":
+                return fake_extmanager_call
+            else:
+                return extension.ExtensionManager.make_test_instance(
+                    extensions=[], namespace=namespace)
+
+        with mock.patch.object(extension, "ExtensionManager") as m_ext_manager:
+            with mock.patch.object(
+                plugins, "_show_plugins_ascii_table"
+            ) as m_show:
+                m_ext_manager.side_effect = m_list_available
+                plugins.show_plugins()
+                m_show.assert_called_once_with(
+                    [('watcher_strategies.strategy_1', 'strategy_1',
+                      'watcher.tests.decision_engine.'
+                      'fake_strategies.FakeDummy1Strategy1')])