Show a pretty progressbar when uploading and downloading an image.

Add a new module that contain generic wrapper for file and iterator, which
are used to wrap image to upload and the request body iterator in upload and
download cases repectively, to show and advance a pretty progress bar when this
laters are consumed, The progress bar is triggered by adding a --progress command
line argument to commands: image-create, image-download or image-update.

Change-Id: I2ba42fd0c58f4fa087adb568ec3f08246cae3759
bug fix: LP#1112309
blueprint: progressbar-when-uploading

tests/v2/test_shell_v2.py

@@ -15,11 +15,16 @@
 #    under the License.
 # vim: tabstop=4 shiftwidth=4 softtabstop=4
 
+import StringIO
+
 import mock
 import testtools
 
+from glanceclient.common import http
+from glanceclient.common import progressbar
 from glanceclient.common import utils
 from glanceclient.v2 import shell as test_shell
+from tests import utils as test_utils
 
 
 class ShellV2Test(testtools.TestCase):
@@ -109,15 +114,32 @@ class ShellV2Test(testtools.TestCase):
             self.gc.schemas.get.assert_called_once_with('test')
 
     def test_image_download(self):
-        args = self._make_args({'id': 'pass', 'file': 'test'})
+        args = self._make_args(
+            {'id': 'pass', 'file': 'test', 'progress': False})
 
         with mock.patch.object(self.gc.images, 'data') as mocked_data:
-            mocked_data.return_value = 'test_passed'
-
+            resp = test_utils.FakeResponse({}, StringIO.StringIO('CCC'))
+            ret = mocked_data.return_value = http.ResponseBodyIterator(resp)
             test_shell.do_image_download(self.gc, args)
 
             mocked_data.assert_called_once_with('pass')
-            utils.save_image.assert_called_once_with('test_passed', 'test')
+            utils.save_image.assert_called_once_with(ret, 'test')
+
+    def test_image_download_with_progressbar(self):
+        args = self._make_args(
+            {'id': 'pass', 'file': 'test', 'progress': True})
+
+        with mock.patch.object(self.gc.images, 'data') as mocked_data:
+            resp = test_utils.FakeResponse({}, StringIO.StringIO('CCC'))
+            mocked_data.return_value = http.ResponseBodyIterator(resp)
+            test_shell.do_image_download(self.gc, args)
+
+            mocked_data.assert_called_once_with('pass')
+            utils.save_image.assert_called_once_with(mock.ANY, 'test')
+            self.assertIsInstance(
+                utils.save_image.call_args[0][0],
+                progressbar.VerboseIteratorWrapper
+            )
 
     def test_do_image_delete(self):
         args = self._make_args({'id': 'pass', 'file': 'test'})