Improve error log when snapshot fails

If snapshot creation via glance fails due to lack of space or over
quota, we want to have a clearer error message.

Change-Id: Ic9133f6bc14d4fe766d37a438bf52c33e89da768
Closes-Bug: #1613770

nova/exception.py

@@ -615,6 +615,11 @@ class ImageBadRequest(Invalid):
                 "%(response)s")
 
 
+class ImageQuotaExceeded(NovaException):
+    msg_fmt = _("Quota exceeded or out of space for image %(image_id)s "
+                "in the image service.")
+
+
 class InstanceUnacceptable(Invalid):
     msg_fmt = _("Instance %(instance_id)s is unacceptable: %(reason)s")
 

nova/image/glance.py

@@ -938,6 +938,8 @@ def _translate_image_exception(image_id, exc_value):
     if isinstance(exc_value, glanceclient.exc.BadRequest):
         return exception.ImageBadRequest(image_id=image_id,
                                          response=six.text_type(exc_value))
+    if isinstance(exc_value, glanceclient.exc.HTTPOverLimit):
+        return exception.ImageQuotaExceeded(image_id=image_id)
     return exc_value
 
 

nova/tests/unit/image/test_glance.py

@@ -305,6 +305,11 @@ class TestExceptionTranslations(test.NoDBTestCase):
         out_exc = glance._translate_image_exception('123', in_exc)
         self.assertIsInstance(out_exc, exception.ImageNotFound)
 
+    def test_client_httpoverlimit_converts_to_imagequotaexceeded(self):
+        in_exc = glanceclient.exc.HTTPOverLimit('123')
+        out_exc = glance._translate_image_exception('123', in_exc)
+        self.assertIsInstance(out_exc, exception.ImageQuotaExceeded)
+
 
 class TestGlanceSerializer(test.NoDBTestCase):
     def test_serialize(self):