Fix failover logic

Author: InvalidInterrupt

etcd3/client.py

@@ -274,7 +274,7 @@ def channel(self):
         # We're failing over. We get the first non-failed channel
         # we encounter, and use it by calling this function again,
         # recursively
-        for label, endpoint in self.endpoints:
+        for label, endpoint in self.endpoints.items():
             if endpoint.is_failed():
                 continue
             self._current_endpoint_label = label

tests/test_etcd3.py

@@ -909,6 +909,19 @@ def test_connection_timeout_exception_on_connection_timeout(self, etcd):
                 etcd.get("foo")
             assert etcd.endpoint_in_use.is_failed()
 
+    def test_single_endpoint_failover(self, etcd):
+        etcd.failover = True
+        exception = self.MockedException(grpc.StatusCode.UNAVAILABLE)
+        kv_mock = mock.PropertyMock()
+        kv_mock.Range.side_effect = exception
+        with mock.patch('etcd3.Etcd3Client.kvstub',
+                        new_callable=mock.PropertyMock) as property_mock:
+            property_mock.return_value = kv_mock
+            with pytest.raises(etcd3.exceptions.ConnectionFailedError):
+                etcd.get("foo")
+        with pytest.raises(etcd3.exceptions.NoServerAvailableError):
+            etcd.get("foo")
+
     def test_grpc_exception_on_unknown_code(self, etcd):
         exception = self.MockedException(grpc.StatusCode.DATA_LOSS)
         kv_mock = mock.PropertyMock()