Add validataion for uploaded files

If user upload yaml of json file, client should validate that file
has correct format.

Change-Id: I5d9f5966da49cff1f034b17c1bbf8eafed758b31
Closes-bug: #1523130

fuelclient/cli/serializers.py

@@ -21,6 +21,7 @@ import yaml
 
 from fuelclient.cli import error
 from fuelclient import consts
+from fuelclient import utils
 
 
 class Serializer(object):
@@ -30,11 +31,11 @@ class Serializer(object):
     serializers = {
         "json": {
             "w": lambda d: json.dumps(d, indent=4),
-            "r": lambda d: json.loads(d)
+            "r": utils.safe_deserialize(json.loads)
         },
         "yaml": {
             "w": lambda d: yaml.safe_dump(d, default_flow_style=False),
-            "r": lambda d: yaml.load(d)
+            "r": utils.safe_deserialize(yaml.load)
         }
     }
 

fuelclient/tests/unit/common/test_serializers.py

@@ -57,6 +57,13 @@ class TestSerializers(base.UnitTestCase):
             deserialized = Serializer(format).deserialize(serialized)
             self.assertEqual(self.DATA, deserialized)
 
+    def test_deserialize_fail(self):
+
+        broken_data = '{foo: bar: buzz:}'
+        for format in ('json', 'yaml'):
+            self.assertRaises(error.BadDataException,
+                              Serializer(format).deserialize, broken_data)
+
     def test_write_to_path_invalid_file_exception(self):
         serializer = Serializer('json')
         mo = mock.mock_open()

fuelclient/utils.py

@@ -14,6 +14,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+import functools
 import glob
 import io
 import json
@@ -173,3 +174,23 @@ def find_exec(program):
         candidate = os.path.join(path, program)
         if os.path.isfile(candidate) and os.access(candidate, os.X_OK):
             return candidate
+
+
+def safe_deserialize(loader):
+    """Wrapper for deserializers.
+
+    Exceptions are raising during deserialization will be transformed
+    into BadDataException
+
+    :param loader: deserializer function
+    :return: wrapped loader
+    """
+    @functools.wraps(loader)
+    def wrapper(data):
+        try:
+            return loader(data)
+        except (ValueError, TypeError, yaml.error.YAMLError) as e:
+            raise error.BadDataException('{0}: {1}'
+                                         ''.format(e.__class__.__name__,
+                                                   six.text_type(e)))
+    return wrapper