Extract group functions into a utility module.

This patch extracts group checking functions into a dedicated module so
that resource implementations are simplified.  The module could later be
used by the autoscaling engine as well.

Change-Id: I99cdd8c9e8fe377e6923ab047a9c2ef08d1defad
partial-blueprint: reorg-asg-code
partial-blueprint: as-lib

heat/common/grouputils.py

@@ -0,0 +1,62 @@
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+import six
+
+
+def get_size(group):
+    """Get number of member resources managed by the specified group.
+
+    The list of members are not sorted or returned.
+    """
+    if group.nested():
+        resources = [r for r in six.itervalues(group.nested())
+                     if r.status != r.FAILED]
+        return len(resources)
+    else:
+        return 0
+
+
+def get_members(group):
+    """Get a list of member resources managed by the specified group.
+
+    Sort the list of instances first by created_time then by name.
+    """
+    resources = []
+    if group.nested():
+        resources = [r for r in six.itervalues(group.nested())
+                     if r.status != r.FAILED]
+
+    return sorted(resources, key=lambda r: (r.created_time, r.name))
+
+
+def get_member_refids(group, exclude=None):
+    """Get a list of member resources managed by the specified group.
+
+    The list of resources is sorted first by created_time then by name.
+    """
+    members = get_members(group)
+    if len(members) == 0:
+        return []
+
+    if exclude is None:
+        exclude = []
+    return [r.FnGetRefId() for r in members
+            if r.FnGetRefId() not in exclude]
+
+
+def get_member_names(group):
+    """Get a list of resource names of the resources in the specified group.
+    Failed resources will be ignored.
+    """
+    return [r.name for r in get_members(group)]

heat/engine/resources/aws/autoscaling_group.py

@@ -16,6 +16,7 @@
 import six
 
 from heat.common import exception
+from heat.common import grouputils
 from heat.common.i18n import _
 from heat.common.i18n import _LI
 from heat.engine import constraints
@@ -213,7 +214,7 @@ def check_create_complete(self, task):
         done = super(AutoScalingGroup, self).check_create_complete(task)
         if done:
             self._cooldown_timestamp(
-                "%s : %s" % (EXACT_CAPACITY, len(self.get_instances())))
+                "%s : %s" % (EXACT_CAPACITY, grouputils.get_size(self)))
         return done
 
     def handle_update(self, json_snippet, tmpl_diff, prop_diff):
@@ -241,7 +242,7 @@ def handle_update(self, json_snippet, tmpl_diff, prop_diff):
                 self.adjust(self.properties[self.DESIRED_CAPACITY],
                             adjustment_type=EXACT_CAPACITY)
             else:
-                current_capacity = len(self.get_instances())
+                current_capacity = grouputils.get_size(self)
                 self.adjust(current_capacity, adjustment_type=EXACT_CAPACITY)
 
     def adjust(self, adjustment, adjustment_type=CHANGE_IN_CAPACITY):
@@ -255,7 +256,7 @@ def adjust(self, adjustment, adjustment_type=CHANGE_IN_CAPACITY):
                       'cooldown': self.properties[self.COOLDOWN]})
             return
 
-        capacity = len(self.get_instances())
+        capacity = grouputils.get_size(self)
         lower = self.properties[self.MIN_SIZE]
         upper = self.properties[self.MAX_SIZE]
 

heat/engine/resources/instance_group.py

@@ -15,6 +15,7 @@
 
 from heat.common import environment_format
 from heat.common import exception
+from heat.common import grouputils
 from heat.common.i18n import _
 from heat.common import timeutils as iso8601utils
 from heat.engine import attributes
@@ -165,24 +166,6 @@ def validate_launchconfig(self):
                                        lc=self.LAUNCH_CONFIGURATION_NAME,
                                        ref=conf_refid))
 
-    def get_instance_names(self):
-        """Get a list of resource names of the instances in this InstanceGroup.
-
-        Failed resources will be ignored.
-        """
-        return [r.name for r in self.get_instances()]
-
-    def get_instances(self):
-        """Get a list of all the instance resources managed by this group.
-
-        Sort the list of instances first by created_time then by name.
-        """
-        resources = []
-        if self.nested():
-            resources = [resource for resource in self.nested().itervalues()
-                         if resource.status != resource.FAILED]
-        return sorted(resources, key=lambda r: (r.created_time, r.name))
-
     def _environment(self):
         """Return the environment for the nested stack."""
         return {
@@ -232,8 +215,8 @@ def handle_update(self, json_snippet, tmpl_diff, prop_diff):
             # Get the current capacity, we may need to adjust if
             # Size has changed
             if self.SIZE in prop_diff:
-                inst_list = self.get_instances()
-                if len(inst_list) != self.properties[self.SIZE]:
+                curr_size = grouputils.get_size(self)
+                if curr_size != self.properties[self.SIZE]:
                     self.resize(self.properties[self.SIZE])
 
     def _tags(self):
@@ -270,7 +253,7 @@ def _get_instance_definition(self):
     def _get_instance_templates(self):
         """Get templates for resource instances."""
         return [(instance.name, instance.t)
-                for instance in self.get_instances()]
+                for instance in grouputils.get_members(self)]
 
     def _create_template(self, num_instances, num_replace=0,
                          template_version=('HeatTemplateFormatVersion',
@@ -301,7 +284,7 @@ def _replace(self, min_in_service, batch_size, pause_sec):
         Replace the instances in the group using updated launch configuration
         """
         def changing_instances(tmpl):
-            instances = self.get_instances()
+            instances = grouputils.get_members(self)
             current = set((i.name, i.t) for i in instances)
             updated = set(tmpl.resource_definitions(self.nested()).items())
             # includes instances to be updated and deleted
@@ -374,8 +357,7 @@ def _lb_reload(self, exclude=None):
         '''
         exclude = exclude or []
         if self.properties[self.LOAD_BALANCER_NAMES]:
-            id_list = [inst.FnGetRefId() for inst in self.get_instances()
-                       if inst.FnGetRefId() not in exclude]
+            id_list = grouputils.get_member_refids(self, exclude=exclude)
             for lb in self.properties[self.LOAD_BALANCER_NAMES]:
                 lb_resource = self.stack[lb]
 
@@ -408,7 +390,7 @@ def _resolve_attribute(self, name):
         '''
         if name == self.INSTANCE_LIST:
             return u','.join(inst.FnGetAtt('PublicIp')
-                             for inst in self.get_instances()) or None
+                             for inst in grouputils.get_members(self)) or None
 
     def child_template(self):
         num_instances = int(self.properties[self.SIZE])

heat/engine/resources/openstack/autoscaling_group.py

@@ -12,6 +12,7 @@
 #    under the License.
 
 from heat.common import exception
+from heat.common import grouputils
 from heat.common.i18n import _
 from heat.engine import attributes
 from heat.engine import constraints
@@ -148,10 +149,10 @@ def _create_template(self, num_instances, num_replace=0,
 
     def FnGetAtt(self, key, *path):
         if key == self.CURRENT_SIZE:
-            return len(self.get_instances())
+            return grouputils.get_size(self)
         if path:
-            attrs = ((rsrc.name,
-                      rsrc.FnGetAtt(*path)) for rsrc in self.get_instances())
+            members = grouputils.get_members(self)
+            attrs = ((rsrc.name, rsrc.FnGetAtt(*path)) for rsrc in members)
             if key == self.OUTPUTS:
                 return dict(attrs)
             if key == self.OUTPUTS_LIST:

heat/tests/autoscaling/test_scaling_group.py

@@ -16,6 +16,7 @@
 import six
 
 from heat.common import exception
+from heat.common import grouputils
 from heat.common import template_format
 from heat.engine import scheduler
 from heat.tests.autoscaling import inline_templates
@@ -178,14 +179,14 @@ def setUp(self):
     def test_scaling_policy_cooldown_toosoon(self):
         """If _cooldown_inprogress() returns True don't progress."""
 
-        dont_call = self.patchobject(self.group, 'get_instances')
+        dont_call = self.patchobject(grouputils, 'get_members')
         with mock.patch.object(self.group, '_cooldown_inprogress',
                                return_value=True):
             self.group.adjust(1)
         self.assertEqual([], dont_call.call_args_list)
 
     def test_scaling_policy_cooldown_ok(self):
-        self.patchobject(self.group, 'get_instances', return_value=[])
+        self.patchobject(grouputils, 'get_members', return_value=[])
         resize = self.patchobject(self.group, 'resize')
         cd_stamp = self.patchobject(self.group, '_cooldown_timestamp')
         notify = self.patch('heat.engine.notification.autoscaling.send')
@@ -213,7 +214,7 @@ def test_scaling_policy_cooldown_ok(self):
         cd_stamp.assert_called_once_with('ChangeInCapacity : 1')
 
     def test_scaling_policy_resize_fail(self):
-        self.patchobject(self.group, 'get_instances', return_value=[])
+        self.patchobject(grouputils, 'get_members', return_value=[])
         self.patchobject(self.group, 'resize',
                          side_effect=ValueError('test error'))
         notify = self.patch('heat.engine.notification.autoscaling.send')

heat/tests/test_autoscaling.py

@@ -20,6 +20,7 @@
 import six
 
 from heat.common import exception
+from heat.common import grouputils
 from heat.common import short_id
 from heat.common import template_format
 from heat.engine.notification import autoscaling as notification
@@ -260,7 +261,7 @@ def test_scaling_group_update_replace(self):
         rsrc = self.create_scaling_group(t, stack, 'WebServerGroup')
         self.assertEqual(utils.PhysName(stack.name, rsrc.name),
                          rsrc.FnGetRefId())
-        self.assertEqual(1, len(rsrc.get_instance_names()))
+        self.assertEqual(1, len(grouputils.get_member_names(rsrc)))
         props = copy.copy(rsrc.properties.data)
         props['AvailabilityZones'] = ['foo']
         update_snippet = rsrc_defn.ResourceDefinition(rsrc.name,
@@ -284,7 +285,7 @@ def test_scaling_group_suspend(self):
         rsrc = self.create_scaling_group(t, stack, 'WebServerGroup')
         self.assertEqual(utils.PhysName(stack.name, rsrc.name),
                          rsrc.FnGetRefId())
-        self.assertEqual(1, len(rsrc.get_instance_names()))
+        self.assertEqual(1, len(grouputils.get_member_names(rsrc)))
         self.assertEqual((rsrc.CREATE, rsrc.COMPLETE), rsrc.state)
 
         self.m.VerifyAll()
@@ -311,7 +312,7 @@ def test_scaling_group_resume(self):
         rsrc = self.create_scaling_group(t, stack, 'WebServerGroup')
         self.assertEqual(utils.PhysName(stack.name, rsrc.name),
                          rsrc.FnGetRefId())
-        self.assertEqual(1, len(rsrc.get_instance_names()))
+        self.assertEqual(1, len(grouputils.get_member_names(rsrc)))
         self.assertEqual((rsrc.CREATE, rsrc.COMPLETE), rsrc.state)
 
         self.m.VerifyAll()
@@ -344,7 +345,7 @@ def test_scaling_group_suspend_multiple(self):
         rsrc = self.create_scaling_group(t, stack, 'WebServerGroup')
         self.assertEqual(utils.PhysName(stack.name, rsrc.name),
                          rsrc.FnGetRefId())
-        self.assertEqual(2, len(rsrc.get_instance_names()))
+        self.assertEqual(2, len(grouputils.get_member_names(rsrc)))
         self.assertEqual((rsrc.CREATE, rsrc.COMPLETE), rsrc.state)
 
         self.m.VerifyAll()
@@ -374,7 +375,7 @@ def test_scaling_group_resume_multiple(self):
         rsrc = self.create_scaling_group(t, stack, 'WebServerGroup')
         self.assertEqual(utils.PhysName(stack.name, rsrc.name),
                          rsrc.FnGetRefId())
-        self.assertEqual(2, len(rsrc.get_instance_names()))
+        self.assertEqual(2, len(grouputils.get_member_names(rsrc)))
         self.assertEqual((rsrc.CREATE, rsrc.COMPLETE), rsrc.state)
 
         self.m.VerifyAll()
@@ -406,7 +407,7 @@ def test_scaling_group_suspend_fail(self):
         rsrc = self.create_scaling_group(t, stack, 'WebServerGroup')
         self.assertEqual(utils.PhysName(stack.name, rsrc.name),
                          rsrc.FnGetRefId())
-        self.assertEqual(1, len(rsrc.get_instance_names()))
+        self.assertEqual(1, len(grouputils.get_member_names(rsrc)))
         self.assertEqual((rsrc.CREATE, rsrc.COMPLETE), rsrc.state)
 
         self.m.VerifyAll()
@@ -436,7 +437,7 @@ def test_scaling_group_resume_fail(self):
         rsrc = self.create_scaling_group(t, stack, 'WebServerGroup')
         self.assertEqual(utils.PhysName(stack.name, rsrc.name),
                          rsrc.FnGetRefId())
-        self.assertEqual(1, len(rsrc.get_instance_names()))
+        self.assertEqual(1, len(grouputils.get_member_names(rsrc)))
         self.assertEqual((rsrc.CREATE, rsrc.COMPLETE), rsrc.state)
 
         self.m.VerifyAll()
@@ -480,7 +481,7 @@ def test_scaling_group_create_error(self):
                           scheduler.TaskRunner(rsrc.create))
         self.assertEqual((rsrc.CREATE, rsrc.FAILED), rsrc.state)
 
-        self.assertEqual([], rsrc.get_instance_names())
+        self.assertEqual([], grouputils.get_members(rsrc))
 
         self.m.VerifyAll()
 
@@ -520,7 +521,7 @@ def test_lb_reload_static_resolve(self):
         rsrc = self.create_scaling_group(t, stack, 'WebServerGroup')
         self.assertEqual(utils.PhysName(stack.name, rsrc.name),
                          rsrc.FnGetRefId())
-        self.assertEqual(1, len(rsrc.get_instance_names()))
+        self.assertEqual(1, len(grouputils.get_member_names(rsrc)))
         props = copy.copy(rsrc.properties.data)
         props['Cooldown'] = '61'
         update_snippet = rsrc_defn.ResourceDefinition(rsrc.name,
@@ -627,7 +628,7 @@ def test_scaling_up_meta_update(self):
         self.m.ReplayAll()
         rsrc = self.create_scaling_group(t, stack, 'WebServerGroup')
         stack.resources['WebServerGroup'] = rsrc
-        self.assertEqual(1, len(rsrc.get_instance_names()))
+        self.assertEqual(1, len(grouputils.get_member_names(rsrc)))
 
         # Scale up one
         self._stub_lb_reload(2)
@@ -641,7 +642,7 @@ def test_scaling_up_meta_update(self):
         alarm_url = up_policy.FnGetAtt('AlarmUrl')
         self.assertIsNotNone(alarm_url)
         up_policy.signal()
-        self.assertEqual(2, len(rsrc.get_instance_names()))
+        self.assertEqual(2, len(grouputils.get_member_names(rsrc)))
 
         # Check CustomLB metadata was updated
         self.m.StubOutWithMock(instance.Instance, '_ipaddress')
@@ -668,7 +669,7 @@ def test_scaling_policy_update(self):
         self.m.ReplayAll()
         rsrc = self.create_scaling_group(t, stack, 'WebServerGroup')
         stack.resources['WebServerGroup'] = rsrc
-        self.assertEqual(1, len(rsrc.get_instance_names()))
+        self.assertEqual(1, len(grouputils.get_member_names(rsrc)))
 
         # Create initial scaling policy
         up_policy = self.create_scaling_policy(t, stack,
@@ -683,7 +684,7 @@ def test_scaling_policy_update(self):
 
         # Trigger alarm
         up_policy.signal()
-        self.assertEqual(2, len(rsrc.get_instance_names()))
+        self.assertEqual(2, len(grouputils.get_member_names(rsrc)))
 
         # Update scaling policy
         props = copy.copy(up_policy.properties.data)
@@ -717,7 +718,7 @@ def test_scaling_policy_update(self):
 
         # Trigger alarm
         up_policy.signal()
-        self.assertEqual(4, len(rsrc.get_instance_names()))
+        self.assertEqual(4, len(grouputils.get_member_names(rsrc)))
 
         rsrc.delete()
         self.m.VerifyAll()
@@ -736,7 +737,7 @@ def test_vpc_zone_identifier(self):
         self.m.ReplayAll()
 
         rsrc = self.create_scaling_group(t, stack, 'WebServerGroup')
-        instances = rsrc.get_instances()
+        instances = grouputils.get_members(rsrc)
         self.assertEqual(1, len(instances))
         self.assertEqual('xxxx', instances[0].properties['SubnetId'])