py3: use binary mode for opening image files

If binary mode is not used when running with python3 glance image
uploads fail as files are opened with encoding='UTF-8' by default.

It results in the following confusing error message:

UnicodeDecodeError: 'utf-8' codec can't decode byte 0xfb in position 3:
invalid start byte

(Pdb) e
UnicodeDecodeError('utf-8', b'QFI\xfb\x00\x00\

0xfb is a QCOW magic string and is invalid from UTF-8 standard
perspective. From the QCOW2 spec:

Byte  0 -  3:   magic
                QCOW magic string ("QFI\xfb")

Tracing have shown that the error comes from python-glanceclient when a
file handle passed to it is attempted to be used for sending image
chunks.

Change-Id: I6bb31fe1d3f79a8fd4707a5576204dee69a3f307
Depends-On: I4991acccefd4754e209feafd5e24d03c76c283f8
Closes-Bug: #1819274

rally_openstack/services/image/glance_v1.py

@@ -52,7 +52,7 @@ class GlanceV1Service(service.Service, glance_common.GlanceMixin):
 
         try:
             if os.path.isfile(image_location):
-                kwargs["data"] = open(image_location)
+                kwargs["data"] = open(image_location, "rb")
             else:
                 kwargs["copy_from"] = image_location
 

rally_openstack/services/image/glance_v2.py

@@ -44,7 +44,7 @@ class GlanceV2Service(service.Service, glance_common.GlanceMixin):
         response = None
         try:
             if os.path.isfile(image_location):
-                image_data = open(image_location)
+                image_data = open(image_location, "rb")
             else:
                 response = requests.get(image_location, stream=True)
                 image_data = response.raw

tests/unit/services/image/test_glance_v1.py

@@ -70,7 +70,7 @@ class GlanceV1ServiceTestCase(test.TestCase):
 
         if location.startswith("/"):
             call_args["data"] = mock_open.return_value
-            mock_open.assert_called_once_with(location)
+            mock_open.assert_called_once_with(location, "rb")
             mock_open.return_value.close.assert_called_once_with()
         else:
             call_args["copy_from"] = location

tests/unit/services/image/test_glance_v2.py

@@ -51,7 +51,7 @@ class GlanceV2ServiceTestCase(test.TestCase):
         self.service.upload_data(image_id, image_location=location)
 
         if location.startswith("/"):
-            mock_open.assert_called_once_with(location)
+            mock_open.assert_called_once_with(location, "rb")
             mock_open.return_value.close.assert_called_once_with()
             self.gc.images.upload.assert_called_once_with(
                 image_id, mock_open.return_value)