Fix the hard-coded etcd cluster size

In before, the etcd cluster size was hard-coded to 1, since HA mode
hadn't been implemented at that time. Now, we fix it. The etcd
cluster size is set to the number of master nodes.

Change-Id: I198ca604401bc805f31e8187f5245177761edf56
Closes-Bug: #1491602

magnum/conductor/template_definition.py

@@ -376,11 +376,9 @@ class AtomicK8sTemplateDefinition(BaseTemplateDefinition):
         if hasattr(bay, 'discovery_url') and bay.discovery_url:
             discovery_url = bay.discovery_url
         else:
-            # TODO(hongbin): Eliminate hard coding of the size when multiple
-            # masters is supported.
             discovery_endpoint = (
                 cfg.CONF.bay.etcd_discovery_service_endpoint_format %
-                {'size': 1})
+                {'size': bay.master_count})
             discovery_url = requests.get(discovery_endpoint).text
             bay.discovery_url = discovery_url
 

magnum/tests/unit/conductor/test_template_definition.py

@@ -166,6 +166,26 @@ class AtomicK8sTemplateDefinitionTestCase(base.TestCase):
         mock_get_params.assert_called_once_with(mock_context, mock_baymodel,
                                                 mock_bay, **expected_kwargs)
 
+    @mock.patch('requests.get')
+    def test_k8s_get_discovery_url(self, mock_get):
+        cfg.CONF.set_override('etcd_discovery_service_endpoint_format',
+                              'http://etcd/test?size=%(size)d',
+                              group='bay')
+        expected_discovery_url = 'http://etcd/token'
+        mock_resp = mock.MagicMock()
+        mock_resp.text = expected_discovery_url
+        mock_get.return_value = mock_resp
+        mock_bay = mock.MagicMock()
+        mock_bay.master_count = 10
+        mock_bay.discovery_url = None
+
+        k8s_def = tdef.AtomicK8sTemplateDefinition()
+        discovery_url = k8s_def.get_discovery_url(mock_bay)
+
+        mock_get.assert_called_once_with('http://etcd/test?size=10')
+        self.assertEqual(mock_bay.discovery_url, expected_discovery_url)
+        self.assertEqual(discovery_url, expected_discovery_url)
+
 
 class AtomicSwarmTemplateDefinitionTestCase(base.TestCase):