add the validation of MaxSize ,MinSize and DesiredCapacity

* check whether MinSize is less than MaxSize
* check whether MinSize and MaxSize is not less than 0
* if DesiredCapacity is offered,check whether it is between
  MinSize and MaxSize

Change-Id: I79a7b6c0e61f109ac7e71d3fd48d93fb741bbc64
Closes-Bug: #1270070

heat/engine/resources/autoscaling.py

@@ -650,6 +650,24 @@ class AutoScalingGroup(InstanceGroup, CooldownMixin):
         if res:
             return res
 
+        # check validity of group size
+        min_size = int(self.properties[self.MIN_SIZE])
+        max_size = int(self.properties[self.MAX_SIZE])
+
+        if max_size < min_size:
+            msg = _("MinSize can not be greater than MaxSize")
+            raise exception.StackValidationFailed(message=msg)
+
+        if min_size < 0:
+            msg = _("The size of AutoScalingGroup can not be less than zero")
+            raise exception.StackValidationFailed(message=msg)
+
+        if self.properties[self.DESIRED_CAPACITY]:
+            desired_capacity = int(self.properties[self.DESIRED_CAPACITY])
+            if desired_capacity < min_size or desired_capacity > max_size:
+                msg = _("DesiredCapacity must be between MinSize and MaxSize")
+                raise exception.StackValidationFailed(message=msg)
+
         # TODO(pasquier-s): once Neutron is able to assign subnets to
         # availability zones, it will be possible to specify multiple subnets.
         # For now, only one subnet can be specified. The bug #1096017 tracks

heat/tests/test_autoscaling.py

@@ -1526,3 +1526,49 @@ class AutoScalingTest(HeatTestCase):
 
         self.assertRaises(exception.NotSupported, self.create_scaling_group, t,
                           stack, 'WebServerGroup')
+
+    def test_invalid_min_size(self):
+        t = template_format.parse(as_template)
+        properties = t['Resources']['WebServerGroup']['Properties']
+        properties['MinSize'] = '-1'
+        properties['MaxSize'] = '2'
+
+        stack = utils.parse_stack(t, params=self.params)
+
+        e = self.assertRaises(exception.StackValidationFailed,
+                              self.create_scaling_group, t,
+                              stack, 'WebServerGroup')
+
+        expected_msg = "The size of AutoScalingGroup can not be less than zero"
+        self.assertEqual(expected_msg, str(e))
+
+    def test_invalid_max_size(self):
+        t = template_format.parse(as_template)
+        properties = t['Resources']['WebServerGroup']['Properties']
+        properties['MinSize'] = '3'
+        properties['MaxSize'] = '1'
+
+        stack = utils.parse_stack(t, params=self.params)
+
+        e = self.assertRaises(exception.StackValidationFailed,
+                              self.create_scaling_group, t,
+                              stack, 'WebServerGroup')
+
+        expected_msg = "MinSize can not be greater than MaxSize"
+        self.assertEqual(expected_msg, str(e))
+
+    def test_invalid_desiredcapacity(self):
+        t = template_format.parse(as_template)
+        properties = t['Resources']['WebServerGroup']['Properties']
+        properties['MinSize'] = '1'
+        properties['MaxSize'] = '3'
+        properties['DesiredCapacity'] = '4'
+
+        stack = utils.parse_stack(t, params=self.params)
+
+        e = self.assertRaises(exception.StackValidationFailed,
+                              self.create_scaling_group, t,
+                              stack, 'WebServerGroup')
+
+        expected_msg = "DesiredCapacity must be between MinSize and MaxSize"
+        self.assertEqual(expected_msg, str(e))