Merge "Add plugin base"

rally/common/plugin.py

@@ -0,0 +1,74 @@
+# Copyright 2015: Mirantis Inc.
+# All Rights Reserved.
+#
+#    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.
+
+from rally.common import utils
+from rally import exceptions
+
+
+def deprecated(reason, rally_version):
+    """Put this decorator on function or class to mark plugin as deprecated.
+
+    :param reason: Message that describes why plugin was deprecated
+    :param rally_version: version of Rally when this plugin was deprecated
+    """
+    def wrapper(plugin):
+        plugin._plugin_deprecated = {
+            "reason": reason,
+            "rally_version": rally_version
+        }
+        return plugin
+
+    return wrapper
+
+
+def plugin(name):
+    """Put this decorator on top of plugin to specify it's name.
+
+    This will be used for everything except Scenarios plugins. They have
+    different nature.
+
+    :param name: name of plugin that is used for searching purpose
+    """
+
+    def wrapper(plugin):
+        plugin._plugin_name = name
+        return plugin
+
+    return wrapper
+
+
+class Plugin(object):
+    """Use this class as a base for all plugins in Rally."""
+
+    @classmethod
+    def get_name(cls):
+        return getattr(cls, "_plugin_name", None)
+
+    @classmethod
+    def get(cls, name):
+        for _plugin in cls.get_all():
+            if _plugin.get_name() == name:
+                return _plugin
+
+        raise exceptions.NoSuchPlugin(name=name)
+
+    @classmethod
+    def get_all(cls):
+        return list(utils.itersubclasses(cls))
+
+    @classmethod
+    def is_deprecated(cls):
+        """Return deprecation details for deprecated plugins."""
+        return getattr(cls, "_plugin_deprecated", False)

rally/exceptions.py

@@ -115,6 +115,10 @@ class NotFoundException(RallyException):
     msg_fmt = _("Not found.")
 
 
+class NoSuchPlugin(NotFoundException):
+    msg_fmt = _("There is no plugin with name: `%(name)s`.")
+
+
 class NoSuchEngine(NotFoundException):
     msg_fmt = _("There is no engine with name `%(engine_name)s`.")
 

tests/unit/common/test_plugin.py

@@ -0,0 +1,80 @@
+# Copyright 2015: Mirantis Inc.
+# All Rights Reserved.
+#
+#    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.
+
+from rally.common import plugin
+from rally import exceptions
+from tests.unit import test
+
+
+@plugin.plugin("base_plugin")
+class BasePlugin(plugin.Plugin):
+    pass
+
+
+@plugin.plugin("some_plugin")
+class SomePlugin(BasePlugin):
+    pass
+
+
+@plugin.deprecated("some_reason", "0.1.1")
+@plugin.plugin("deprecated_plugin")
+class DeprecatedPlugin(BasePlugin):
+    pass
+
+
+class PluginModuleTestCase(test.TestCase):
+
+    def test_deprecated(self):
+
+        @plugin.deprecated("some", "0.0.1")
+        def func():
+            return 42
+
+        self.assertEqual(func._plugin_deprecated,
+                         {"reason": "some", "rally_version": "0.0.1"})
+
+        self.assertEqual(func(), 42)
+
+    def test_plugin(self):
+
+        @plugin.plugin(name="test")
+        def func():
+            return 42
+
+        self.assertEqual(func._plugin_name, "test")
+        self.assertEqual(func(), 42)
+
+
+class PluginTestCase(test.TestCase):
+
+    def test_get_name(self):
+        self.assertEqual("some_plugin", SomePlugin.get_name())
+
+    def test_get(self):
+        self.assertEqual(SomePlugin,
+                         BasePlugin.get("some_plugin"))
+
+    def test_get_not_found(self):
+        self.assertRaises(exceptions.NoSuchPlugin,
+                          BasePlugin.get, "non_existing")
+
+    def test_get_all(self):
+        self.assertEqual([SomePlugin, DeprecatedPlugin], BasePlugin.get_all())
+        self.assertEqual([], SomePlugin.get_all())
+
+    def test_is_deprecated(self):
+        self.assertFalse(SomePlugin.is_deprecated())
+        self.assertEqual(DeprecatedPlugin.is_deprecated(),
+                         {"reason": "some_reason", "rally_version": "0.1.1"})