Remove capacity check from AWS::AG update

When heat is trying to update autoscaling group resource with
the same template an exception is raised because nested stack
is not in (UPDATE, COMPLETE) state. It happens because heat
doesn't change the state of nested stacks if size of Autoscaling
group has not been changed. So fix allows handle_update in
AWS::AutoscalingGroup to launch resize despite of changes
in AG capacity.

Change-Id: Ibb71f31f2ec7d1d37b995323a2474b799ea498bb
Closes-bug: #1429134

heat/engine/resources/aws/autoscaling/autoscaling_group.py

@@ -310,11 +310,6 @@ class AutoScalingGroup(instgrp.InstanceGroup, cooldown.CooldownMixin):
 
         new_capacity = _calculate_new_capacity(capacity, adjustment,
                                                adjustment_type, lower, upper)
-        total = grouputils.get_size(self, include_failed=True)
-        # if there are failed resources in nested_stack, has to change
-        if new_capacity == total:
-            LOG.debug('no change in capacity %d' % capacity)
-            return
 
         # send a notification before, on-error and on-success.
         notif = {

heat/tests/autoscaling/test_heat_scaling_group.py

@@ -137,6 +137,36 @@ class TestGroupAdjust(common.HeatTestCase):
             self.group.adjust(1)
         self.assertEqual([], dont_call.call_args_list)
 
+    def test_scaling_same_capacity(self):
+        """Alway resize even if the capacity is the same."""
+        self.patchobject(grouputils, 'get_size', return_value=3)
+        resize = self.patchobject(self.group, 'resize')
+        cd_stamp = self.patchobject(self.group, '_cooldown_timestamp')
+        notify = self.patch('heat.engine.notification.autoscaling.send')
+        self.patchobject(self.group, '_cooldown_inprogress',
+                         return_value=False)
+        self.group.adjust(3, adjustment_type='ExactCapacity')
+
+        expected_notifies = [
+            mock.call(
+                capacity=3, suffix='start',
+                adjustment_type='ExactCapacity',
+                groupname=u'my-group',
+                message=u'Start resizing the group my-group',
+                adjustment=3,
+                stack=self.group.stack),
+            mock.call(
+                capacity=3, suffix='end',
+                adjustment_type='ExactCapacity',
+                groupname=u'my-group',
+                message=u'End resizing the group my-group',
+                adjustment=3,
+                stack=self.group.stack)]
+
+        self.assertEqual(expected_notifies, notify.call_args_list)
+        resize.assert_called_once_with(3)
+        cd_stamp.assert_called_once_with('ExactCapacity : 3')
+
     def test_scaling_policy_cooldown_ok(self):
         self.patchobject(grouputils, 'get_members', return_value=[])
         resize = self.patchobject(self.group, 'resize')

heat/tests/autoscaling/test_scaling_group.py

@@ -316,6 +316,36 @@ class TestGroupAdjust(common.HeatTestCase):
             self.group.adjust(1)
         self.assertEqual([], dont_call.call_args_list)
 
+    def test_scaling_same_capacity(self):
+        """Alway resize even if the capacity is the same."""
+        self.patchobject(grouputils, 'get_size', return_value=3)
+        resize = self.patchobject(self.group, 'resize')
+        cd_stamp = self.patchobject(self.group, '_cooldown_timestamp')
+        notify = self.patch('heat.engine.notification.autoscaling.send')
+        self.patchobject(self.group, '_cooldown_inprogress',
+                         return_value=False)
+        self.group.adjust(3, adjustment_type='ExactCapacity')
+
+        expected_notifies = [
+            mock.call(
+                capacity=3, suffix='start',
+                adjustment_type='ExactCapacity',
+                groupname=u'WebServerGroup',
+                message=u'Start resizing the group WebServerGroup',
+                adjustment=3,
+                stack=self.group.stack),
+            mock.call(
+                capacity=3, suffix='end',
+                adjustment_type='ExactCapacity',
+                groupname=u'WebServerGroup',
+                message=u'End resizing the group WebServerGroup',
+                adjustment=3,
+                stack=self.group.stack)]
+
+        self.assertEqual(expected_notifies, notify.call_args_list)
+        resize.assert_called_once_with(3)
+        cd_stamp.assert_called_once_with('ExactCapacity : 3')
+
     def test_scaling_policy_cooldown_ok(self):
         self.patchobject(grouputils, 'get_members', return_value=[])
         resize = self.patchobject(self.group, 'resize')

heat_integrationtests/functional/test_heat_autoscaling.py

@@ -97,3 +97,39 @@ outputs:
         expected_resources = {'random_group': 'OS::Heat::AutoScalingGroup'}
         self.assertEqual(expected_resources, self.list_resources(stack_id))
         self._assert_output_values(stack_id)
+
+
+class AutoScalingGroupUpdateWithNoChanges(test.HeatIntegrationTest):
+
+    template = '''
+heat_template_version: 2013-05-23
+
+resources:
+  test_group:
+    type: OS::Heat::AutoScalingGroup
+    properties:
+      desired_capacity: 0
+      max_size: 0
+      min_size: 0
+      resource:
+        type: OS::Heat::RandomString
+  test_policy:
+    type: OS::Heat::ScalingPolicy
+    properties:
+      adjustment_type: change_in_capacity
+      auto_scaling_group_id: { get_resource: test_group }
+      scaling_adjustment: 1
+'''
+
+    def setUp(self):
+        super(AutoScalingGroupUpdateWithNoChanges, self).setUp()
+        self.client = self.orchestration_client
+
+    def test_as_group_update_without_resource_changes(self):
+        stack_identifier = self.stack_create(template=self.template)
+        new_template = self.template.replace(
+            'scaling_adjustment: 1',
+            'scaling_adjustment: 2')
+
+        self.update_stack(stack_identifier, template=new_template)
+        self._wait_for_stack_status(stack_identifier, 'UPDATE_COMPLETE')