Merge "Use stevedore to load client plugins"

heat/engine/clients/__init__.py

@@ -19,6 +19,7 @@ from neutronclient.v2_0 import client as neutronclient
 from novaclient import client as novaclient
 from novaclient import shell as novashell
 from oslo.config import cfg
+from stevedore import extension
 from swiftclient import client as swiftclient
 from troveclient import client as troveclient
 import warnings
@@ -45,18 +46,36 @@ class OpenStackClients(object):
     '''
     Convenience class to create and cache client instances.
     '''
+
     def __init__(self, context):
         self.context = context
         self._clients = {}
+        self._client_plugins = {}
+
+    def client_plugin(self, name):
+        global _mgr
+        if name in self._client_plugins:
+            return self._client_plugins[name]
+        if _mgr and name in _mgr.names():
+            client_plugin = _mgr[name].plugin(self)
+            self._client_plugins[name] = client_plugin
+            return client_plugin
 
     def client(self, name):
+        client_plugin = self.client_plugin(name)
+        if client_plugin:
+            return client_plugin.client()
+
         if name in self._clients:
             return self._clients[name]
+        # call the local method _<name>() if a real client plugin
+        # doesn't exist
         method_name = '_%s' % name
         if callable(getattr(self, method_name, None)):
             client = getattr(self, method_name)()
             self._clients[name] = client
             return client
+        LOG.warn(_('Requested client "%s" not found') % name)
 
     @property
     def auth_token(self):
@@ -326,3 +345,21 @@ class ClientBackend(object):
 
 
 Clients = ClientBackend
+
+
+_mgr = None
+
+
+def has_client(name):
+    return _mgr and name in _mgr
+
+
+def initialise():
+    global _mgr
+    if _mgr:
+        return
+
+    _mgr = extension.ExtensionManager(
+        namespace='heat.clients',
+        invoke_on_load=False,
+        verify_requirements=True)

heat/engine/resources/__init__.py

@@ -13,6 +13,7 @@
 
 from stevedore import extension
 
+from heat.engine import clients
 from heat.engine import environment
 from heat.engine import plugin_manager
 
@@ -49,6 +50,8 @@ def initialise():
     if _environment is not None:
         return
 
+    clients.initialise()
+
     global_env = environment.Environment({}, user_env=False)
     _load_global_environment(global_env)
     _environment = global_env

heat/tests/test_clients.py

@@ -11,10 +11,10 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from heatclient import client as heatclient
 import mock
 from oslo.config import cfg
-
-from heatclient import client as heatclient
+from testtools.testcase import skip
 
 from heat.engine import clients
 from heat.engine.clients import client_plugin
@@ -172,3 +172,32 @@ class ClientPluginTest(HeatTestCase):
         con = mock.Mock()
         c = clients.Clients(con)
         self.assertRaises(TypeError, client_plugin.ClientPlugin, c)
+
+
+class TestClientPluginsInitialise(HeatTestCase):
+
+    @skip('skipped until keystone can read context auth_ref')
+    def test_create_all_clients(self):
+        con = mock.Mock()
+        con.auth_url = "http://auth.example.com:5000/v2.0"
+        con.tenant_id = "b363706f891f48019483f8bd6503c54b"
+        con.auth_token = "3bcc3d3a03f44e3d8377f9247b0ad155"
+        c = clients.Clients(con)
+
+        for plugin_name in clients._mgr.names():
+            self.assertTrue(clients.has_client(plugin_name))
+            c.client(plugin_name)
+
+    def test_create_all_client_plugins(self):
+        plugin_types = clients._mgr.names()
+        self.assertIsNotNone(plugin_types)
+
+        con = mock.Mock()
+        c = clients.Clients(con)
+
+        for plugin_name in plugin_types:
+            plugin = c.client_plugin(plugin_name)
+            self.assertIsNotNone(plugin)
+            self.assertEqual(c, plugin.clients)
+            self.assertEqual(con, plugin.context)
+            self.assertIsNone(plugin._client)