Check that all defined entry points can be loaded

Stevedore will silently ignore an entry point that cannot be loaded so
this new test will check that all the entry points defined for the auth
plugins can be loaded.

Change-Id: I6c778e13e0f151ee6d47376277e84920678d0564

keystoneauth1/tests/unit/loading/test_entry_points.py

@@ -0,0 +1,35 @@
+# 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 stevedore
+
+from keystoneauth1 import loading
+from keystoneauth1.tests.unit.loading import utils
+
+
+class EntryPointTests(utils.TestCase):
+    """Simple test that will check that all entry points are loadable."""
+
+    def test_all_entry_points_are_valid(self):
+        errors = []
+
+        def raise_exception_callback(manager, entrypoint, exc):
+            error = ("Cannot load '%(entrypoint)s' entry_point: %(error)s'" %
+                     {"entrypoint": entrypoint, "error": exc})
+            errors.append(error)
+
+        stevedore.ExtensionManager(
+            namespace=loading.PLUGIN_NAMESPACE,
+            on_load_failure_callback=raise_exception_callback
+        )
+
+        self.assertEqual([], errors)