Implements stack lifecycle scheduler hints

This is a mechanism whereby when heat processes
a stack VM resource, the stack id, root stack id,
stack resource id, stack resource name and the
path in the stack (as a list of tuples,
(stackresourcename, stackname)) can be passed to
nova by heat as scheduler hints, to the
configured schedulers for nova.

Implements: blueprint stack-lifecycle-scheduler-hint
Co-Authored-By: Karolyn Chambers <chamberk@us.ibm.com>

Change-Id: I3e006339a41c469451bc3ee740018b285d3e0a65

doc/source/index.rst

@@ -53,6 +53,7 @@ Developers Documentation
 
    architecture
    pluginguide
+   schedulerhints
 
 API Documentation
 ========================

doc/source/schedulerhints.rst

@@ -0,0 +1,41 @@
+..
+      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.
+
+====================================
+Heat Stack Lifecycle Scheduler Hints
+====================================
+This is a mechanism whereby when heat processes a stack Server resource, the
+stack id, root stack id, stack resource id, stack resource name and the path
+in the stack can be passed to nova by heat as scheduler hints, to the
+configured schedulers for nova.
+
+
+Enabling the scheduler hints
+----------------------------
+By default, passing the lifecycle scheduler hints is disabled. To enable it,
+set stack_scheduler_hints to True in heat.conf.
+
+The hints
+---------
+When heat processes a stack, and the feature is enabled, the stack id, root
+stack id, stack resource id, stack resource name and the path in the stack
+(as a list of tuple, (stackresourcename, stackname)) will be passed to nova
+by heat as scheduler hints, to the configured schedulers for nova.
+
+Purpose
+-------
+A heat provider may have a need for custom code to examine stack requests
+prior to performing the operations to create or update a stack. After the
+custom code completes, the provider may want to provide hints to the nova
+scheduler with stack related identifiers, for processing by any custom
+scheduler plug-ins configured for nova.

heat/common/config.py

@@ -189,7 +189,24 @@ engine_opts = [
                       'resource-signal using the provided keystone '
                       'credentials')),
     cfg.StrOpt('onready',
-               help=_('Deprecated.'))]
+               help=_('Deprecated.')),
+    cfg.BoolOpt('stack_scheduler_hints',
+                default=False,
+                help=_('When this feature is enabled, scheduler hints'
+                       ' identifying the heat stack context of a server'
+                       ' resource are passed to the configured schedulers in'
+                       ' nova, for server creates done using heat resource'
+                       ' types OS::Nova::Server and AWS::EC2::Instance.'
+                       ' heat_root_stack_id will be set to the id of the root'
+                       ' stack of the resource, heat_stack_id will be set to'
+                       ' the id of the resource\'s parent stack,'
+                       ' heat_stack_name will be set to the name of the'
+                       ' resource\'s parent stack, heat_path_in_stack will be'
+                       ' set to a list of tuples,'
+                       ' (stackresourcename, stackname) with list[0] being'
+                       ' (None, rootstackname), and heat_resource_name will'
+                       ' be set to the resource\'s name.'))]
+
 
 rpc_opts = [
     cfg.StrOpt('host',

heat/engine/resources/aws/ec2/instance.py

@@ -28,6 +28,7 @@ from heat.engine import scheduler
 from heat.engine import volume_tasks as vol_task
 
 cfg.CONF.import_opt('instance_user', 'heat.common.config')
+cfg.CONF.import_opt('stack_scheduler_hints', 'heat.common.config')
 
 LOG = logging.getLogger(__name__)
 
@@ -524,6 +525,14 @@ class Instance(resource.Resource):
                     scheduler_hints[hint] = hint_value
         else:
             scheduler_hints = None
+        if cfg.CONF.stack_scheduler_hints:
+            if scheduler_hints is None:
+                scheduler_hints = {}
+            scheduler_hints['heat_root_stack_id'] = self.stack.root_stack.id
+            scheduler_hints['heat_stack_id'] = self.stack.id
+            scheduler_hints['heat_stack_name'] = self.stack.name
+            scheduler_hints['heat_path_in_stack'] = self.stack.path_in_stack()
+            scheduler_hints['heat_resource_name'] = self.name
 
         nics = self._build_nics(self.properties[self.NETWORK_INTERFACES],
                                 security_groups=security_groups,

heat/engine/resources/openstack/nova/server.py

@@ -35,6 +35,7 @@ from heat.rpc import api as rpc_api
 
 cfg.CONF.import_opt('instance_user', 'heat.common.config')
 cfg.CONF.import_opt('default_software_config_transport', 'heat.common.config')
+cfg.CONF.import_opt('stack_scheduler_hints', 'heat.common.config')
 
 LOG = logging.getLogger(__name__)
 
@@ -651,6 +652,14 @@ class Server(stack_user.StackUser):
                 instance_meta)
 
         scheduler_hints = self.properties.get(self.SCHEDULER_HINTS)
+        if cfg.CONF.stack_scheduler_hints:
+            if scheduler_hints is None:
+                scheduler_hints = {}
+            scheduler_hints['heat_root_stack_id'] = self.stack.root_stack.id
+            scheduler_hints['heat_stack_id'] = self.stack.id
+            scheduler_hints['heat_stack_name'] = self.stack.name
+            scheduler_hints['heat_path_in_stack'] = self.stack.path_in_stack()
+            scheduler_hints['heat_resource_name'] = self.name
         nics = self._build_nics(self.properties.get(self.NETWORKS))
         block_device_mapping = self._build_block_device_mapping(
             self.properties.get(self.BLOCK_DEVICE_MAPPING))

heat/engine/stack.py

@@ -251,6 +251,32 @@ class Stack(collections.Mapping):
             return self.parent_resource.stack.root_stack
         return self
 
+    def object_path_in_stack(self):
+        '''
+        If this is not nested return (None, self), else return stack resources
+        and stacks in path from the root stack and including this stack
+
+        :returns: a list of (stack_resource, stack) tuples
+        '''
+        if self.parent_resource and self.parent_resource.stack:
+            path = self.parent_resource.stack.object_path_in_stack()
+            path.extend([(self.parent_resource, self)])
+            return path
+        return [(None, self)]
+
+    def path_in_stack(self):
+        '''
+        If this is not nested return (None, self.name), else return tuples of
+        names (stack_resource.name, stack.name) in path from the root stack and
+        including this stack.
+
+        :returns: a list of (string, string) tuples.
+
+        '''
+        opis = self.object_path_in_stack()
+        return [(stckres.name if stckres else None,
+                 stck.name if stck else None) for stckres, stck in opis]
+
     def total_resources(self):
         '''
         Return the total number of resources in a stack, including nested

heat/tests/test_instance.py

@@ -520,6 +520,46 @@ class InstancesTest(common.HeatTestCase):
 
         self.m.VerifyAll()
 
+    def test_instance_create_with_stack_scheduler_hints(self):
+        return_server = self.fc.servers.list()[1]
+        instances.cfg.CONF.set_override('stack_scheduler_hints', True)
+        # Unroll _create_test_instance, to enable check
+        # for addition of heat ids (stack id, resource name)
+        stack_name = 'test_instance_create_with_stack_scheduler_hints'
+        (t, stack) = self._get_test_template(stack_name)
+        resource_defns = t.resource_definitions(stack)
+        instance = instances.Instance('in_create_with_sched_hints',
+                                      resource_defns['WebServer'], stack)
+        bdm = {"vdb": "9ef5496e-7426-446a-bbc8-01f84d9c9972:snap::True"}
+        self._mock_get_image_id_success('CentOS 5.2', 1)
+
+        self.m.StubOutWithMock(nova.NovaClientPlugin, '_create')
+        nova.NovaClientPlugin._create().AndReturn(self.fc)
+        self.stub_SnapshotConstraint_validate()
+
+        self.m.StubOutWithMock(self.fc.servers, 'create')
+        self.fc.servers.create(
+            image=1, flavor=1, key_name='test',
+            name=utils.PhysName(
+                stack_name,
+                instance.name,
+                limit=instance.physical_resource_name_limit),
+            security_groups=None,
+            userdata=mox.IgnoreArg(),
+            scheduler_hints={'heat_root_stack_id': stack.root_stack.id,
+                             'heat_stack_id': stack.id,
+                             'heat_stack_name': stack.name,
+                             'heat_path_in_stack': [(None, stack.name)],
+                             'heat_resource_name': instance.name,
+                             'foo': ['spam', 'ham', 'baz'], 'bar': 'eggs'},
+            meta=None, nics=None, availability_zone=None,
+            block_device_mapping=bdm).AndReturn(
+                return_server)
+        self.m.ReplayAll()
+        scheduler.TaskRunner(instance.create)()
+        self.assertTrue(instance.id > 0)
+        self.m.VerifyAll()
+
     def test_instance_validate(self):
         stack_name = 'test_instance_validate_stack'
         (tmpl, stack) = self._setup_test_stack(stack_name)

heat/tests/test_server.py

@@ -879,6 +879,49 @@ class ServersTest(common.HeatTestCase):
             config_drive=None, disk_config=None, reservation_id=None,
             files={}, admin_pass='foo')
 
+    def test_server_create_with_stack_scheduler_hints(self):
+        return_server = self.fc.servers.list()[1]
+        return_server.id = '5678'
+        servers.cfg.CONF.set_override('stack_scheduler_hints', True)
+        # Unroll _create_test_server, to enable check
+        # for addition of heat ids (stack id, resource name)
+        stack_name = 'test_server_w_stack_sched_hints_s'
+        server_name = 'server_w_stack_sched_hints'
+        (t, stack) = self._get_test_template(stack_name, server_name)
+
+        resource_defns = t.resource_definitions(stack)
+        server = servers.Server(server_name,
+                                resource_defns['WebServer'], stack)
+
+        self._mock_get_image_id_success('CentOS 5.2', 1,
+                                        server_rebuild=False)
+
+        self.m.StubOutWithMock(nova.NovaClientPlugin, '_create')
+        nova.NovaClientPlugin._create().MultipleTimes().AndReturn(self.fc)
+
+        self.m.StubOutWithMock(self.fc.servers, 'create')
+        self.fc.servers.create(
+            image=1, flavor=1, key_name='test',
+            name=server_name,
+            security_groups=[],
+            userdata=mox.IgnoreArg(),
+            scheduler_hints={'heat_root_stack_id': stack.root_stack.id,
+                             'heat_stack_id': stack.id,
+                             'heat_stack_name': stack.name,
+                             'heat_path_in_stack': [(None, stack.name)],
+                             'heat_resource_name': server.name},
+            meta=None, nics=None, availability_zone=None,
+            block_device_mapping=None, block_device_mapping_v2=None,
+            config_drive=None, disk_config=None, reservation_id=None,
+            files={}, admin_pass=None).AndReturn(return_server)
+
+        self.m.ReplayAll()
+        scheduler.TaskRunner(server.create)()
+        # this makes sure the auto increment worked on server creation
+        self.assertTrue(server.id > 0)
+
+        self.m.VerifyAll()
+
     def test_check_maximum(self):
         msg = 'test_check_maximum'
         self.assertIsNone(servers.Server._check_maximum(1, 1, msg))