Ensure endpoint_id is set

The endpoint_id option is required because it is the key to look up
the target endpoint from Keystone catalog. This ensures more sensible
error is shown in case endpoint id is not set, instead of trying to
look up endpoint by 'None'.

Change-Id: I43859dec08040130e4e5fa6ad65b74be21489aff

oslo_limit/limit.py

@@ -264,6 +264,8 @@ class _EnforcerUtils(object):
 
         # get and cache endpoint info
         endpoint_id = CONF.oslo_limit.endpoint_id
+        if not endpoint_id:
+            raise ValueError("endpoint_id is not configured")
         self._endpoint = self.connection.get_endpoint(endpoint_id)
         if not self._endpoint:
             raise ValueError("can't find endpoint for %s" % endpoint_id)

oslo_limit/tests/test_fixture.py

@@ -13,15 +13,28 @@
 
 from oslotest import base
 
+from oslo_config import cfg
+from oslo_config import fixture as config_fixture
+
 from oslo_limit import exception
 from oslo_limit import fixture
 from oslo_limit import limit
+from oslo_limit import opts
+
+CONF = cfg.CONF
 
 
 class TestFixture(base.BaseTestCase):
     def setUp(self):
         super(TestFixture, self).setUp()
 
+        self.config_fixture = self.useFixture(config_fixture.Config(CONF))
+        self.config_fixture.config(
+            group='oslo_limit',
+            endpoint_id='ENDPOINT_ID'
+        )
+        opts.register_opts(CONF)
+
         # Set up some default projects, registered limits,
         # and project limits
         reglimits = {'widgets': 100,

oslo_limit/tests/test_limit.py

@@ -46,6 +46,10 @@ class TestEnforcer(base.BaseTestCase):
             group='oslo_limit',
             auth_type='password'
         )
+        self.config_fixture.config(
+            group='oslo_limit',
+            endpoint_id='ENDPOINT_ID'
+        )
         opts.register_opts(CONF)
         self.config_fixture.config(
             group='oslo_limit',
@@ -223,6 +227,12 @@ class TestEnforcer(base.BaseTestCase):
 class TestFlatEnforcer(base.BaseTestCase):
     def setUp(self):
         super(TestFlatEnforcer, self).setUp()
+        self.config_fixture = self.useFixture(config_fixture.Config(CONF))
+        self.config_fixture.config(
+            group='oslo_limit',
+            endpoint_id='ENDPOINT_ID'
+        )
+        opts.register_opts(CONF)
         self.mock_conn = mock.MagicMock()
         limit._SDK_CONNECTION = self.mock_conn
 
@@ -259,7 +269,7 @@ class TestFlatEnforcer(base.BaseTestCase):
         enforcer = limit._FlatEnforcer(mock_usage)
         enforcer.enforce(project_id, deltas)
 
-        self.mock_conn.get_endpoint.assert_called_once_with(None)
+        self.mock_conn.get_endpoint.assert_called_once_with('ENDPOINT_ID')
         mock_get_limits.assert_called_once_with(project_id, ["a", "b"])
         mock_usage.assert_called_once_with(project_id, ["a", "b"])
 
@@ -310,6 +320,12 @@ class TestFlatEnforcer(base.BaseTestCase):
 class TestEnforcerUtils(base.BaseTestCase):
     def setUp(self):
         super(TestEnforcerUtils, self).setUp()
+        self.config_fixture = self.useFixture(config_fixture.Config(CONF))
+        self.config_fixture.config(
+            group='oslo_limit',
+            endpoint_id='ENDPOINT_ID'
+        )
+        opts.register_opts(CONF)
         self.mock_conn = mock.MagicMock()
         limit._SDK_CONNECTION = self.mock_conn
 
@@ -320,7 +336,7 @@ class TestEnforcerUtils(base.BaseTestCase):
         utils = limit._EnforcerUtils()
 
         self.assertEqual(fake_endpoint, utils._endpoint)
-        self.mock_conn.get_endpoint.assert_called_once_with(None)
+        self.mock_conn.get_endpoint.assert_called_once_with('ENDPOINT_ID')
 
     def test_get_registered_limit_empty(self):
         self.mock_conn.registered_limits.return_value = iter([])