Merge "Add a new method get_decoded_user_data to the metadata services"

cloudbaseinit/metadata/services/base.py

@@ -15,6 +15,8 @@
 
 import abc
 import collections
+import gzip
+import io
 import time
 
 from oslo_config import cfg
@@ -63,6 +65,8 @@ class NotExistingMetadataException(Exception):
 
 @six.add_metaclass(abc.ABCMeta)
 class BaseMetadataService(object):
+    _GZIP_MAGIC_NUMBER = b'\x1f\x8b'
+
     def __init__(self):
         self._cache = {}
         self._enable_retry = False
@@ -113,6 +117,21 @@ class BaseMetadataService(object):
     def get_user_data(self):
         pass
 
+    def get_decoded_user_data(self):
+        """Get the decoded user data, if any
+
+        The user data can be gzip-encoded, which means
+        that every access to it should verify this fact,
+        leading to code duplication.
+        """
+        user_data = self.get_user_data()
+        if user_data and user_data[:2] == self._GZIP_MAGIC_NUMBER:
+            bio = io.BytesIO(user_data)
+            with gzip.GzipFile(fileobj=bio, mode='rb') as out:
+                user_data = out.read()
+
+        return user_data
+
     def get_host_name(self):
         pass
 

cloudbaseinit/plugins/common/userdata.py

@@ -13,8 +13,6 @@
 #    under the License.
 
 import email
-import gzip
-import io
 
 from oslo_log import log as oslo_logging
 
@@ -36,7 +34,7 @@ class UserDataPlugin(base.BasePlugin):
 
     def execute(self, service, shared_data):
         try:
-            user_data = service.get_user_data()
+            user_data = service.get_decoded_user_data()
         except metadata_services_base.NotExistingMetadataException:
             return base.PLUGIN_EXECUTION_DONE, False
 
@@ -44,18 +42,8 @@ class UserDataPlugin(base.BasePlugin):
             return base.PLUGIN_EXECUTION_DONE, False
 
         LOG.debug('User data content length: %d' % len(user_data))
-        user_data = self._check_gzip_compression(user_data)
-
         return self._process_user_data(user_data)
 
-    def _check_gzip_compression(self, user_data):
-        if user_data[:2] == self._GZIP_MAGIC_NUMBER:
-            bio = io.BytesIO(user_data)
-            with gzip.GzipFile(fileobj=bio, mode='rb') as f:
-                user_data = f.read()
-
-        return user_data
-
     @staticmethod
     def _parse_mime(user_data):
         user_data_str = encoding.get_as_string(user_data)

cloudbaseinit/tests/metadata/services/test_base.py

@@ -0,0 +1,37 @@
+# Copyright 2015 Cloudbase Solutions Srl
+#
+#    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 unittest
+
+from cloudbaseinit.metadata.services import base
+
+
+class FakeService(base.BaseMetadataService):
+    def _get_data(self):
+        return (b'\x1f\x8b\x08\x00\x93\x90\xf2U\x02'
+                b'\xff\xcbOSH\xce/-*NU\xc8,Q(\xcf/\xca.'
+                b'\x06\x00\x12:\xf6a\x12\x00\x00\x00')
+
+    def get_user_data(self):
+        return self._get_data()
+
+
+class TestBase(unittest.TestCase):
+
+    def setUp(self):
+        self._service = FakeService()
+
+    def test_get_decoded_user_data(self):
+        userdata = self._service.get_decoded_user_data()
+        self.assertEqual(b"of course it works", userdata)

cloudbaseinit/tests/plugins/common/test_userdata.py

@@ -34,7 +34,7 @@ class FakeService(object):
     def __init__(self, user_data):
         self.user_data = user_data
 
-    def get_user_data(self):
+    def get_decoded_user_data(self):
         return self.user_data.encode()
 
 
@@ -53,26 +53,18 @@ class UserDataPluginTest(unittest.TestCase):
 
     @mock.patch('cloudbaseinit.plugins.common.userdata.UserDataPlugin'
                 '._process_user_data')
-    @mock.patch('cloudbaseinit.plugins.common.userdata.UserDataPlugin'
-                '._check_gzip_compression')
-    def _test_execute(self, mock_check_gzip_compression,
-                      mock_process_user_data, ret_val):
+    def _test_execute(self, mock_process_user_data, ret_val):
         mock_service = mock.MagicMock()
-        mock_service.get_user_data.side_effect = [ret_val]
+        mock_service.get_decoded_user_data.side_effect = [ret_val]
 
         response = self._userdata.execute(service=mock_service,
                                           shared_data=None)
 
-        mock_service.get_user_data.assert_called_once_with()
+        mock_service.get_decoded_user_data.assert_called_once_with()
         if ret_val is metadata_services_base.NotExistingMetadataException:
             self.assertEqual(response, (base.PLUGIN_EXECUTION_DONE, False))
         elif ret_val is None:
             self.assertEqual(response, (base.PLUGIN_EXECUTION_DONE, False))
-        else:
-            mock_check_gzip_compression.assert_called_once_with(ret_val)
-            mock_process_user_data.assert_called_once_with(
-                mock_check_gzip_compression.return_value)
-            self.assertEqual(response, mock_process_user_data.return_value)
 
     def test_execute(self):
         self._test_execute(ret_val='fake_data')
@@ -87,20 +79,6 @@ class UserDataPluginTest(unittest.TestCase):
     def test_execute_not_user_data(self):
         self._test_execute(ret_val=None)
 
-    @mock.patch('io.BytesIO')
-    @mock.patch('gzip.GzipFile')
-    def test_check_gzip_compression(self, mock_GzipFile, mock_BytesIO):
-        fake_userdata = b'\x1f\x8b'
-        fake_userdata += self._userdata._GZIP_MAGIC_NUMBER
-
-        response = self._userdata._check_gzip_compression(fake_userdata)
-
-        mock_BytesIO.assert_called_once_with(fake_userdata)
-        mock_GzipFile.assert_called_once_with(
-            fileobj=mock_BytesIO.return_value, mode='rb')
-        data = mock_GzipFile().__enter__().read.return_value
-        self.assertEqual(data, response)
-
     @mock.patch('email.message_from_string')
     @mock.patch('cloudbaseinit.utils.encoding.get_as_string')
     def test_parse_mime(self, mock_get_as_string,