Correct the error message for query parameter validation

Currently the error message returned by failed query parameter validation
didn't include correct parameter name. This patch correct that.

Change-Id: Ifd0b37084709c2728749b5b7b317f304b0488269
Closes-Bug: #1655710

2 files changed, 23 insertions, 7 deletions

diff --git a/nova/api/validation/validators.py b/nova/api/validation/validators.py
index 6ac478755d..f3c0c9d1a7 100644
--- a/nova/api/validation/validators.py
+++ b/nova/api/validation/validators.py
@@ -280,14 +280,23 @@ class _SchemaValidator(object):
                     #       message has been written as the similar format of
                     #       WSME.
                     detail = _("Invalid input for field/attribute %(path)s. "
-                               "Value: %(value)s. %(message)s")
+                               "Value: %(value)s. %(message)s") % {
+                        'path': ex.path.pop(),
+                        'value': ex.instance,
+                        'message': ex.message}
                 else:
+                    # NOTE: Use 'ex.path.popleft()' instead of 'ex.path.pop()',
+                    #       due to the structure of query parameters is a dict
+                    #       with key as name and value is list. So the first
+                    #       item in the 'ex.path' is the key, and second item
+                    #       is the index of list in the value. We need the
+                    #       key as the parameter name in the error message.
+                    #       So pop the first value out of 'ex.path'.
                     detail = _("Invalid input for query parameters %(path)s. "
-                               "Value: %(value)s. %(message)s")
-                detail = detail % {
-                    'path': ex.path.pop(), 'value': ex.instance,
-                    'message': ex.message
-                }
+                               "Value: %(value)s. %(message)s") % {
+                        'path': ex.path.popleft(),
+                        'value': ex.instance,
+                        'message': ex.message}
             else:
                 detail = ex.message
             raise exception.ValidationError(detail=detail)
diff --git a/nova/tests/unit/test_api_validation.py b/nova/tests/unit/test_api_validation.py
index eab625c89a..e1861323cf 100644
--- a/nova/tests/unit/test_api_validation.py
+++ b/nova/tests/unit/test_api_validation.py
@@ -271,7 +271,14 @@ class QueryParamsSchemaTestCase(test.NoDBTestCase):
         # parameter 'foo' expect a UUID
         req = fakes.HTTPRequest.blank("/tests?foo=abc")
         req.api_version_request = api_version.APIVersionRequest("2.3")
-        self.assertRaises(exception.ValidationError, self.controller.get, req)
+        ex = self.assertRaises(exception.ValidationError, self.controller.get,
+                               req)
+        if six.PY3:
+            self.assertEqual("Invalid input for query parameters foo. Value: "
+                             "abc. 'abc' is not a 'uuid'", ex.message)
+        else:
+            self.assertEqual("Invalid input for query parameters foo. Value: "
+                             "abc. u'abc' is not a 'uuid'", ex.message)
 
     def test_validate_request_with_multiple_values(self):
         req = fakes.HTTPRequest.blank("/tests?foos=abc")