Fixes the use of dates when listing images

When listing images there are several optional parameters that
can be used to filter the list of images retrieved by the API. The
following two parameters are not working properly: the created_at and
the updated_at. Before the Mitaka release it was possible to use these
filters just using a datetime in the format ISO 8601, starting on
Mitaka, you need to add an operator along with the datetime stamp or
the API call fails. This commit adds backwards compatibility so it is
possible to filter the images list using only a datetime stamp without
also specifing an operator. If no operator is used an eq operator is
assumed.

Change-Id: Id5d5455e77637e0dc7baec25c8163b21634d72c4
Partial-Bug: 1584415

glance/common/utils.py

@@ -44,6 +44,7 @@ import six
 from webob import exc
 
 from glance.common import exception
+from glance.common import timeutils
 from glance.i18n import _, _LE, _LW
 
 CONF = cfg.CONF
@@ -603,8 +604,17 @@ def split_filter_op(expression):
     """
     left, sep, right = expression.partition(':')
     if sep:
-        op = left
-        threshold = right
+        # If the expression is a date of the format ISO 8601 like
+        # CCYY-MM-DDThh:mm:ss+hh:mm and has no operator, it should
+        # not be partitioned, and a default operator of eq should be
+        # assumed.
+        try:
+            timeutils.parse_isotime(expression)
+            op = 'eq'
+            threshold = expression
+        except ValueError:
+            op = left
+            threshold = right
     else:
         op = 'eq'  # default operator
         threshold = left

glance/tests/unit/common/test_utils.py

@@ -450,6 +450,16 @@ class SplitFilterOpTestCase(test_utils.BaseTestCase):
         returned = utils.split_filter_op(expr)
         self.assertEqual(('eq', expr), returned)
 
+    def test_default_operator_with_datetime(self):
+        expr = '2015-08-27T09:49:58Z'
+        returned = utils.split_filter_op(expr)
+        self.assertEqual(('eq', expr), returned)
+
+    def test_operator_with_datetime(self):
+        expr = 'lt:2015-08-27T09:49:58Z'
+        returned = utils.split_filter_op(expr)
+        self.assertEqual(('lt', '2015-08-27T09:49:58Z'), returned)
+
 
 class EvaluateFilterOpTestCase(test_utils.BaseTestCase):