Santhosh/deepak| Load extensions supported by plugin

quantum/common/extensions.py

@@ -24,6 +24,7 @@ import logging
 import webob.dec
 import webob.exc
 
+from quantum.manager import QuantumManager
 from quantum.common import exceptions
 from quantum.common import wsgi
 from gettext import gettext as _
@@ -231,8 +232,9 @@ class ExtensionMiddleware(wsgi.Middleware):
                  ext_mgr=None):
 
         self.ext_mgr = (ext_mgr
-                   or ExtensionManager(config_params.get('api_extensions_path',
-                                                         '')))
+                        or ExtensionManager(
+                config_params.get('api_extensions_path',
+                                  ''), QuantumManager().plugin))
 
         mapper = routes.Mapper()
 
@@ -296,11 +298,11 @@ class ExtensionManager(object):
     example extension implementation.
 
     """
-
-    def __init__(self, path):
+    def __init__(self, path, plugin):
         LOG.info(_('Initializing extension manager.'))
 
         self.path = path
+        self.plugin = plugin
         self.extensions = {}
         self._load_all_extensions()
 
@@ -350,10 +352,10 @@ class ExtensionManager(object):
             LOG.debug(_('Ext description: %s'), extension.get_description())
             LOG.debug(_('Ext namespace: %s'), extension.get_namespace())
             LOG.debug(_('Ext updated: %s'), extension.get_updated())
+            return self.plugin.supports_extension(extension)
         except AttributeError as ex:
             LOG.exception(_("Exception loading extension: %s"), unicode(ex))
             return False
-        return True
 
     def _load_all_extensions(self):
         """Load extensions from the configured path.
@@ -392,7 +394,6 @@ class ExtensionManager(object):
                               'file': ext_path})
                     continue
                 new_ext = new_ext_class()
-                self._check_extension(new_ext)
                 self.add_extension(new_ext)
 
     def add_extension(self, ext):

quantum/manager.py

@@ -26,6 +26,7 @@ The caller should make sure that QuantumManager is a singleton.
 """
 import gettext
 import os
+import logging
 gettext.install('quantum', unicode=1)
 
 import os
@@ -33,6 +34,7 @@ import os
 from common import utils
 from quantum_plugin_base import QuantumPluginBase
 
+LOG = logging.getLogger('quantum.manager')
 CONFIG_FILE = "plugins.ini"
 
 
@@ -51,13 +53,13 @@ class QuantumManager(object):
         else:
             self.configuration_file = config
         plugin_location = utils.getPluginFromConfig(self.configuration_file)
-        print "PLUGIN LOCATION:%s" % plugin_location
+        LOG.debug("PLUGIN LOCATION:%s" % plugin_location)
         plugin_klass = utils.import_class(plugin_location)
         if not issubclass(plugin_klass, QuantumPluginBase):
             raise Exception("Configured Quantum plug-in " \
                             "didn't pass compatibility test")
         else:
-            print("Successfully imported Quantum plug-in." \
+            LOG.debug("Successfully imported Quantum plug-in." \
                   "All compatibility tests passed\n")
         self.plugin = plugin_klass()
 

quantum/plugins/SamplePlugin.py

@@ -434,3 +434,6 @@ class FakePlugin(object):
         # TODO(salvatore-orlando):
         # Should unplug on port without attachment raise an Error?
         port['attachment'] = None
+
+    def supports_extension(self, extension):
+        return True

quantum/quantum_plugin_base.py

@@ -230,6 +230,15 @@ class QuantumPluginBase(object):
         """
         pass
 
+    @abstractmethod
+    def supports_extension(self, extension):
+        """
+        Returns if the extension is suppoorted
+
+        :returns: True or False
+        """
+        pass
+
     @classmethod
     def __subclasshook__(cls, klass):
         """

tests/unit/test_extensions.py

@@ -23,7 +23,7 @@ from webtest import TestApp
 from quantum.common import extensions
 from quantum.common import wsgi
 from quantum.common import config
-
+from quantum.common.extensions import ExtensionManager
 
 extension_index_response = "Try to say this Mr. Knox, sir..."
 test_conf_file = os.path.join(os.path.dirname(__file__), os.pardir,
@@ -71,38 +71,63 @@ class ResourceExtensionTest(unittest.TestCase):
         self.assertEqual(404, response.status_int)
 
 
+class StubExtension(object):
+
+    def __init__(self, alias="stub_extension"):
+        self.alias = alias
+
+    def get_name(self):
+        return "Stub Extension"
+
+    def get_alias(self):
+        return self.alias
+
+    def get_description(self):
+        return ""
+
+    def get_namespace(self):
+        return ""
+
+    def get_updated(self):
+        return ""
+
+
+class StubPlugin(object):
+
+    def __init__(self, supported_extensions=[]):
+        self.supported_extensions = supported_extensions
+
+    def supports_extension(self, extension):
+        return extension.get_alias() in self.supported_extensions
+
+
 class ExtensionManagerTest(unittest.TestCase):
 
     def test_invalid_extensions_are_not_registered(self):
 
-        class ValidExtension(object):
-
-            def get_name(self):
-                return "Valid Extension"
-
-            def get_alias(self):
-                return "valid_extension"
-
-            def get_description(self):
-                return ""
-
-            def get_namespace(self):
-                return ""
-
-            def get_updated(self):
-                return ""
-
         class InvalidExtension(object):
             def get_alias(self):
                 return "invalid_extension"
 
-        extended_app = setup_extensions_middleware()
-        ext_mgr = extended_app.ext_mgr
+        ext_mgr = setup_extensions_middleware().ext_mgr
         ext_mgr.add_extension(InvalidExtension())
-        ext_mgr.add_extension(ValidExtension())
+        ext_mgr.add_extension(StubExtension("valid_extension"))
+
         self.assertTrue('valid_extension' in ext_mgr.extensions)
         self.assertFalse('invalid_extension' in ext_mgr.extensions)
 
+    def test_unsupported_extensions_are_not_loaded(self):
+        ext_mgr = setup_extensions_middleware().ext_mgr
+        ext_mgr.plugin = StubPlugin(supported_extensions=["e1", "e3"])
+
+        ext_mgr.add_extension(StubExtension("e1"))
+        ext_mgr.add_extension(StubExtension("e2"))
+        ext_mgr.add_extension(StubExtension("e3"))
+
+        self.assertTrue("e1" in ext_mgr.extensions)
+        self.assertFalse("e2" in ext_mgr.extensions)
+        self.assertTrue("e3" in ext_mgr.extensions)
+
 
 class ActionExtensionTest(unittest.TestCase):