Use placement for unified resource management

placement restapi integration

Co-Authored-By: Hongbin Lu <hongbin034@gmail.com>
Change-Id: I81fbadd030e486516c6bdcf0526e89a5d58d3e26
Implements: blueprint use-placement-resource-management

lower-constraints.txt

@@ -66,8 +66,10 @@ openstacksdk==0.12.0
 os-api-ref==1.4.0
 os-brick==2.2.0
 os-client-config==1.29.0
+os-resource-classes==0.1.0
 os-service-types==1.2.0
 os-testr==1.0.0
+os-traits==0.15.0
 os-win==4.0.0
 osc-lib==1.10.0
 oslo.cache==1.29.0
@@ -84,8 +86,8 @@ oslo.privsep==1.32.0
 oslo.serialization==2.18.0
 oslo.service==1.24.0
 oslo.upgradecheck==0.1.0
-oslo.utils==3.33.0
+oslo.utils==3.37.0
-oslo.versionedobjects==1.31.2
+oslo.versionedobjects==1.35.0
 oslo.rootwrap==5.8.0
 oslotest==3.2.0
 osprofiler==1.4.0

requirements.txt

@@ -20,13 +20,15 @@ oslo.policy>=1.30.0 # Apache-2.0
 oslo.privsep>=1.32.0 # Apache-2.0
 oslo.serialization!=2.19.1,>=2.18.0 # Apache-2.0
 oslo.service!=1.28.1,>=1.24.0 # Apache-2.0
-oslo.versionedobjects>=1.31.2 # Apache-2.0
+oslo.versionedobjects>=1.35.0 # Apache-2.0
 oslo.context>=2.19.2 # Apache-2.0
-oslo.utils>=3.33.0 # Apache-2.0
+oslo.utils>=3.37.0 # Apache-2.0
 oslo.db>=4.27.0 # Apache-2.0
 oslo.rootwrap>=5.8.0 # Apache-2.0
 oslo.upgradecheck>=0.1.0 # Apache-2.0
 os-brick>=2.2.0 # Apache-2.0
+os-resource-classes>=0.1.0 # Apache-2.0
+os-traits>=0.15.0 # Apache-2.0
 six>=1.10.0 # MIT
 SQLAlchemy!=1.1.5,!=1.1.6,!=1.1.7,!=1.1.8,>=1.0.10 # MIT
 stevedore>=1.20.0 # Apache-2.0

zun/common/clients.py

@@ -14,6 +14,7 @@
 
 from cinderclient import client as cinderclient
 from glanceclient import client as glanceclient
+from keystoneauth1.loading import adapter as ka_adapter
 from neutronclient.v2_0 import client as neutronclient
 
 from zun.common import exception
@@ -30,6 +31,8 @@ class OpenStackClients(object):
         self._glance = None
         self._neutron = None
         self._cinder = None
+        self._placement = None
+        self._placement_ks_filter = None
 
     def url_for(self, **kwargs):
         return self.keystone().session.get_endpoint(**kwargs)
@@ -115,3 +118,26 @@ class OpenStackClients(object):
                                            **kwargs)
 
         return self._cinder
+
+    @exception.wrap_keystone_exception
+    def placement(self):
+        if self._placement:
+            return self._placement, self._placement_ks_filter
+
+        session = self.keystone().session
+        session.verify = \
+            self._get_client_option('placement', 'ca_file') or True
+        if self._get_client_option('placement', 'insecure'):
+            session.verify = False
+        region_name = self._get_client_option('placement', 'region_name')
+        endpoint_type = self._get_client_option('placement', 'endpoint_type')
+        kwargs = {
+            'session': self.keystone().session,
+            'auth': self.keystone().auth,
+        }
+        self._placement_ks_filter = {'service_type': 'placement',
+                                     'region_name': region_name,
+                                     'interface': endpoint_type}
+        self._placement = ka_adapter.Adapter().load_from_options(**kwargs)
+
+        return self._placement, self._placement_ks_filter

zun/common/exception.py

@@ -423,10 +423,6 @@ class ZunServiceNotFound(HTTPNotFound):
     message = _("Zun service %(binary)s on host %(host)s could not be found.")
 
 
-class ResourceProviderNotFound(HTTPNotFound):
-    message = _("Resource provider %(resource_provider)s could not be found.")
-
-
 class ResourceClassNotFound(HTTPNotFound):
     message = _("Resource class %(resource_class)s could not be found.")
 
@@ -776,3 +772,113 @@ class NameEmpty(InvalidReference):
 class NameTooLong(InvalidReference):
     message = _('repository name must not be more than %(length_max)s '
                 'characters')
+
+
+# An exception with this name is used on both sides of the placement/zun
+# interaction.
+class ResourceProviderInUse(ZunException):
+    message = _("Resource provider has allocations.")
+
+
+class ResourceProviderRetrievalFailed(ZunException):
+    message = _("Failed to get resource provider with UUID %(uuid)s")
+
+
+class ResourceProviderAggregateRetrievalFailed(ZunException):
+    message = _("Failed to get aggregates for resource provider with UUID"
+                " %(uuid)s")
+
+
+class ResourceProviderTraitRetrievalFailed(ZunException):
+    message = _("Failed to get traits for resource provider with UUID"
+                " %(uuid)s")
+
+
+class ResourceProviderCreationFailed(ZunException):
+    message = _("Failed to create resource provider %(name)s")
+
+
+class ResourceProviderDeletionFailed(ZunException):
+    message = _("Failed to delete resource provider %(uuid)s")
+
+
+class ResourceProviderUpdateFailed(ZunException):
+    message = _("Failed to update resource provider via URL %(url)s: "
+                "%(error)s")
+
+
+class ResourceProviderNotFound(NotFound):
+    message = _("No such resource provider %(name_or_uuid)s.")
+
+
+class ResourceProviderSyncFailed(ZunException):
+    message = _("Failed to synchronize the placement service with resource "
+                "provider information supplied by the compute host.")
+
+
+class PlacementAPIConnectFailure(ZunException):
+    message = _("Unable to communicate with the Placement API.")
+
+
+class PlacementAPIConflict(ZunException):
+    """Any 409 error from placement APIs should use (a subclass of) this
+    exception.
+    """
+    message = _("A conflict was encountered attempting to invoke the "
+                "placement API at URL %(url)s: %(error)s")
+
+
+class ResourceProviderUpdateConflict(PlacementAPIConflict):
+    """A 409 caused by generation mismatch from attempting to update an
+    existing provider record or its associated data (aggregates, traits, etc.).
+    """
+    message = _("A conflict was encountered attempting to update resource "
+                "provider %(uuid)s (generation %(generation)d): %(error)s")
+
+
+class InvalidResourceClass(Invalid):
+    message = _("Resource class '%(resource_class)s' invalid.")
+
+
+class InvalidResourceAmount(Invalid):
+    message = _("Resource amounts must be integers. Received '%(amount)s'.")
+
+
+class InvalidInventory(Invalid):
+    message = _("Inventory for '%(resource_class)s' on "
+                "resource provider '%(resource_provider)s' invalid.")
+
+
+class UsagesRetrievalFailed(ZunException):
+    message = _("Failed to retrieve usages for project '%(project_id)s' and "
+                "user '%(user_id)s'.")
+
+
+class AllocationUpdateFailed(ZunException):
+    message = _('Failed to update allocations for consumer %(consumer_uuid)s. '
+                'Error: %(error)s')
+
+
+class ConsumerAllocationRetrievalFailed(ZunException):
+    message = _("Failed to retrieve allocations for consumer "
+                "%(consumer_uuid)s: %(error)s")
+
+
+class TraitRetrievalFailed(ZunException):
+    message = _("Failed to get traits for resource provider with UUID"
+                " %(uuid)s")
+
+
+class TraitCreationFailed(ZunException):
+    message = _("Failed to create trait %(name)s: %(error)s")
+
+
+class AllocationMoveFailed(ZunException):
+    message = _('Failed to move allocations from consumer %(source_consumer)s '
+                'to consumer %(target_consumer)s. '
+                'Error: %(error)s')
+
+
+class ResourceProviderAllocationRetrievalFailed(ZunException):
+    message = _("Failed to retrieve allocations for resource provider "
+                "%(rp_uuid)s: %(error)s")

zun/common/keystone.py

@@ -33,6 +33,7 @@ class KeystoneClientV3(object):
         self.context = context
         self._client = None
         self._session = None
+        self._auth = None
 
     @property
     def auth_url(self):
@@ -55,6 +56,14 @@ class KeystoneClientV3(object):
         self._session = session
         return session
 
+    @property
+    def auth(self):
+        if self._auth:
+            return self._auth
+        auth = self._get_auth()
+        self._auth = auth
+        return auth
+
     def _get_session(self, auth):
         session = ka_loading.load_session_from_conf_options(
             CONF, ksconf.CFG_GROUP, auth=auth)

zun/common/utils.py

@@ -18,6 +18,7 @@
 """Utilities and helper functions."""
 import base64
 import binascii
+import contextlib
 import eventlet
 import functools
 import inspect
@@ -716,3 +717,12 @@ def decode_file_data(data):
 
 def strtime(at):
     return at.strftime("%Y-%m-%dT%H:%M:%S.%f")
+
+
+if six.PY2:
+    nested_contexts = contextlib.nested
+else:
+    @contextlib.contextmanager
+    def nested_contexts(*contexts):
+        with contextlib.ExitStack() as stack:
+            yield [stack.enter_context(c) for c in contexts]

zun/compute/api.py

@@ -23,7 +23,7 @@ from zun.compute import container_actions
 from zun.compute import rpcapi
 import zun.conf
 from zun import objects
-from zun.scheduler import client as scheduler_client
+from zun.scheduler.client import query as scheduler_client
 
 
 CONF = zun.conf.CONF

zun/compute/compute_node_tracker.py

@@ -24,7 +24,7 @@ import zun.conf
 from zun import objects
 from zun.objects import base as obj_base
 from zun.pci import manager as pci_manager
-from zun.scheduler import client as scheduler_client
+from zun.scheduler.client import query as scheduler_client
 
 
 CONF = zun.conf.CONF

zun/compute/provider_tree.py

@@ -0,0 +1,680 @@
+#    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.
+
+"""An object describing a tree of resource providers and their inventories.
+
+This object is not stored in the Zun API; rather, this
+object is constructed and used by the scheduler report client to track state
+changes for resources on the container engine. As such, there are
+no remoteable methods nor is there any interaction with the zun.db modules.
+"""
+
+import collections
+import copy
+
+import os_traits
+from oslo_concurrency import lockutils
+from oslo_log import log as logging
+from oslo_utils import uuidutils
+
+from zun.common.i18n import _
+
+
+LOG = logging.getLogger(__name__)
+_LOCK_NAME = 'provider-tree-lock'
+
+# Point-in-time representation of a resource provider in the tree.
+# Note that, whereas namedtuple enforces read-only-ness of containers as a
+# whole, nothing prevents modification of the internals of attributes of
+# complex types (children/inventory/traits/aggregates).  However, any such
+# modifications still have no effect on the ProviderTree the container came
+# from.  Like, you can Sharpie a moustache on a Polaroid of my face, but that
+# doesn't make a moustache appear on my actual face.
+ProviderData = collections.namedtuple(
+    'ProviderData', ['uuid', 'name', 'generation', 'parent_uuid', 'inventory',
+                     'traits', 'aggregates'])
+
+
+class _Provider(object):
+    """Represents a resource provider in the tree. All operations against the
+    tree should be done using the ProviderTree interface, since it controls
+    thread-safety.
+    """
+    def __init__(self, name, uuid=None, generation=None, parent_uuid=None):
+        if uuid is None:
+            uuid = uuidutils.generate_uuid()
+        self.uuid = uuid
+        self.name = name
+        self.generation = generation
+        self.parent_uuid = parent_uuid
+        # Contains a dict, keyed by uuid of child resource providers having
+        # this provider as a parent
+        self.children = {}
+        # dict of inventory records, keyed by resource class
+        self.inventory = {}
+        # Set of trait names
+        self.traits = set()
+        # Set of aggregate UUIDs
+        self.aggregates = set()
+
+    @classmethod
+    def from_dict(cls, pdict):
+        """Factory method producing a _Provider based on a dict with
+        appropriate keys.
+
+        :param pdict: Dictionary representing a provider, with keys 'name',
+                      'uuid', 'generation', 'parent_provider_uuid'.  Of these,
+                      only 'name' is mandatory.
+        """
+        return cls(pdict['name'], uuid=pdict.get('uuid'),
+                   generation=pdict.get('generation'),
+                   parent_uuid=pdict.get('parent_provider_uuid'))
+
+    def data(self):
+        inventory = copy.deepcopy(self.inventory)
+        traits = copy.copy(self.traits)
+        aggregates = copy.copy(self.aggregates)
+        return ProviderData(
+            self.uuid, self.name, self.generation, self.parent_uuid,
+            inventory, traits, aggregates)
+
+    def get_provider_uuids(self):
+        """Returns a list, in top-down traversal order, of UUIDs of this
+        provider and all its descendants.
+        """
+        ret = [self.uuid]
+        for child in self.children.values():
+            ret.extend(child.get_provider_uuids())
+        return ret
+
+    def find(self, search):
+        if self.name == search or self.uuid == search:
+            return self
+        if search in self.children:
+            return self.children[search]
+        if self.children:
+            for child in self.children.values():
+                # We already searched for the child by UUID above, so here we
+                # just check for a child name match
+                if child.name == search:
+                    return child
+                subchild = child.find(search)
+                if subchild:
+                    return subchild
+        return None
+
+    def add_child(self, provider):
+        self.children[provider.uuid] = provider
+
+    def remove_child(self, provider):
+        if provider.uuid in self.children:
+            del self.children[provider.uuid]
+
+    def has_inventory(self):
+        """Returns whether the provider has any inventory records at all. """
+        return self.inventory != {}
+
+    def has_inventory_changed(self, new):
+        """Returns whether the inventory has changed for the provider."""
+        cur = self.inventory
+        if set(cur) != set(new):
+            return True
+        for key, cur_rec in cur.items():
+            new_rec = new[key]
+            # If the new record contains new fields (e.g. we're adding on
+            # `reserved` or `allocation_ratio`) we want to make sure to pick
+            # them up
+            if set(new_rec) - set(cur_rec):
+                return True
+            for rec_key, cur_val in cur_rec.items():
+                if rec_key not in new_rec:
+                    # Deliberately don't want to compare missing keys in the
+                    # *new* inventory record. For instance, we will be passing
+                    # in fields like allocation_ratio in the current dict but
+                    # the resource tracker may only pass in the total field. We
+                    # want to return that inventory didn't change when the
+                    # total field values are the same even if the
+                    # allocation_ratio field is missing from the new record.
+                    continue
+                if new_rec[rec_key] != cur_val:
+                    return True
+        return False
+
+    def _update_generation(self, generation, operation):
+        if generation is not None and generation != self.generation:
+            msg_args = {
+                'rp_uuid': self.uuid,
+                'old': self.generation,
+                'new': generation,
+                'op': operation
+            }
+            LOG.debug("Updating resource provider %(rp_uuid)s generation "
+                      "from %(old)s to %(new)s during operation: %(op)s",
+                      msg_args)
+            self.generation = generation
+
+    def update_inventory(self, inventory, generation):
+        """Update the stored inventory for the provider along with a resource
+        provider generation to set the provider to. The method returns whether
+        the inventory has changed.
+        """
+        self._update_generation(generation, 'update_inventory')
+        if self.has_inventory_changed(inventory):
+            LOG.debug('Updating inventory in ProviderTree for provider %s '
+                      'with inventory: %s', self.uuid, inventory)
+            self.inventory = copy.deepcopy(inventory)
+            return True
+        LOG.debug('Inventory has not changed in ProviderTree for provider: %s',
+                  self.uuid)
+        return False
+
+    def have_traits_changed(self, new):
+        """Returns whether the provider's traits have changed."""
+        return set(new) != self.traits
+
+    def update_traits(self, new, generation=None):
+        """Update the stored traits for the provider along with a resource
+        provider generation to set the provider to. The method returns whether
+        the traits have changed.
+        """
+        self._update_generation(generation, 'update_traits')
+        if self.have_traits_changed(new):
+            self.traits = set(new)  # create a copy of the new traits
+            return True
+        return False
+
+    def has_traits(self, traits):
+        """Query whether the provider has certain traits.
+
+        :param traits: Iterable of string trait names to look for.
+        :return: True if this provider has *all* of the specified traits; False
+                 if any of the specified traits are absent.  Returns True if
+                 the traits parameter is empty.
+        """
+        return not bool(set(traits) - self.traits)
+
+    def have_aggregates_changed(self, new):
+        """Returns whether the provider's aggregates have changed."""
+        return set(new) != self.aggregates
+
+    def update_aggregates(self, new, generation=None):
+        """Update the stored aggregates for the provider along with a resource
+        provider generation to set the provider to. The method returns whether
+        the aggregates have changed.
+        """
+        self._update_generation(generation, 'update_aggregates')
+        if self.have_aggregates_changed(new):
+            self.aggregates = set(new)  # create a copy of the new aggregates
+            return True
+        return False
+
+    def in_aggregates(self, aggregates):
+        """Query whether the provider is a member of certain aggregates.
+
+        :param aggregates: Iterable of string aggregate UUIDs to look for.
+        :return: True if this provider is a member of *all* of the specified
+                 aggregates; False if any of the specified aggregates are
+                 absent.  Returns True if the aggregates parameter is empty.
+        """
+        return not bool(set(aggregates) - self.aggregates)
+
+
+class ProviderTree(object):
+
+    def __init__(self):
+        """Create an empty provider tree."""
+        self.lock = lockutils.internal_lock(_LOCK_NAME)
+        self.roots = []
+
+    def get_provider_uuids(self, name_or_uuid=None):
+        """Return a list, in top-down traversable order, of the UUIDs of all
+        providers (in a (sub)tree).
+
+        :param name_or_uuid: Provider name or UUID representing the root of a
+                             (sub)tree for which to return UUIDs.  If not
+                             specified, the method returns all UUIDs in the
+                             ProviderTree.
+        """
+        if name_or_uuid is not None:
+            with self.lock:
+                return self._find_with_lock(name_or_uuid).get_provider_uuids()
+
+        # If no name_or_uuid, get UUIDs for all providers recursively.
+        ret = []
+        with self.lock:
+            for root in self.roots:
+                ret.extend(root.get_provider_uuids())
+        return ret
+
+    def get_provider_uuids_in_tree(self, name_or_uuid):
+        """Returns a list, in top-down traversable order, of the UUIDs of all
+        providers in the whole tree of which the provider identified by
+        ``name_or_uuid`` is a member.
+
+        :param name_or_uuid: Provider name or UUID representing any member of
+                             whole tree for which to return UUIDs.
+        """
+        with self.lock:
+            return self._find_with_lock(
+                name_or_uuid, return_root=True).get_provider_uuids()
+
+    def populate_from_iterable(self, provider_dicts):
+        """Populates this ProviderTree from an iterable of provider dicts.
+
+        This method will ADD providers to the tree if provider_dicts contains
+        providers that do not exist in the tree already and will REPLACE
+        providers in the tree if provider_dicts contains providers that are
+        already in the tree. This method will NOT remove providers from the
+        tree that are not in provider_dicts.  But if a parent provider is in
+        provider_dicts and the descendents are not, this method will remove the
+        descendents from the tree.
+
+        :param provider_dicts: An iterable of dicts of resource provider
+                               information.  If a provider is present in
+                               provider_dicts, all its descendants must also be
+                               present.
+        :raises: ValueError if any provider in provider_dicts has a parent that
+                 is not in this ProviderTree or elsewhere in provider_dicts.
+        """
+        if not provider_dicts:
+            return
+
+        # Map of provider UUID to provider dict for the providers we're
+        # *adding* via this method.
+        to_add_by_uuid = {pd['uuid']: pd for pd in provider_dicts}
+
+        with self.lock:
+            # Sanity check for orphans.  Every parent UUID must either be None
+            # (the provider is a root), or be in the tree already, or exist as
+            # a key in to_add_by_uuid (we're adding it).
+            all_parents = set([None]) | set(to_add_by_uuid)
+            # NOTE(efried): Can't use get_provider_uuids directly because we're
+            # already under lock.
+            for root in self.roots:
+                all_parents |= set(root.get_provider_uuids())
+            missing_parents = set()
+            for pd in to_add_by_uuid.values():
+                parent_uuid = pd.get('parent_provider_uuid')
+                if parent_uuid not in all_parents:
+                    missing_parents.add(parent_uuid)
+            if missing_parents:
+                raise ValueError(
+                    _("The following parents were not found: %s") %
+                    ', '.join(missing_parents))
+
+            # Ready to do the work.
+            # Use to_add_by_uuid to keep track of which providers are left to
+            # be added.
+            while to_add_by_uuid:
+                # Find a provider that's suitable to inject.
+                for uuid, pd in to_add_by_uuid.items():
+                    # Roots are always okay to inject (None won't be a key in
+                    # to_add_by_uuid).  Otherwise, we have to make sure we
+                    # already added the parent (and, by recursion, all
+                    # ancestors) if present in the input.
+                    parent_uuid = pd.get('parent_provider_uuid')
+                    if parent_uuid not in to_add_by_uuid:
+                        break
+                else:
+                    # This should never happen - we already ensured all parents
+                    # exist in the tree, which means we can't have any branches
+                    # that don't wind up at the root, which means we can't have
+                    # cycles.  But to quell the paranoia...
+                    raise ValueError(
+                        _("Unexpectedly failed to find parents already in the "
+                          "tree for any of the following: %s") %
+                        ','.join(set(to_add_by_uuid)))
+
+                # Add or replace the provider, either as a root or under its
+                # parent
+                try:
+                    self._remove_with_lock(uuid)
+                except ValueError:
+                    # Wasn't there in the first place - fine.
+                    pass
+
+                provider = _Provider.from_dict(pd)
+                if parent_uuid is None:
+                    self.roots.append(provider)
+                else:
+                    parent = self._find_with_lock(parent_uuid)
+                    parent.add_child(provider)
+
+                # Remove this entry to signify we're done with it.
+                to_add_by_uuid.pop(uuid)
+
+    def _remove_with_lock(self, name_or_uuid):
+        found = self._find_with_lock(name_or_uuid)
+        if found.parent_uuid:
+            parent = self._find_with_lock(found.parent_uuid)
+            parent.remove_child(found)
+        else:
+            self.roots.remove(found)
+
+    def remove(self, name_or_uuid):
+        """Safely removes the provider identified by the supplied name_or_uuid
+        parameter and all of its children from the tree.
+
+        :raises ValueError if name_or_uuid points to a non-existing provider.
+        :param name_or_uuid: Either name or UUID of the resource provider to
+                             remove from the tree.
+        """
+        with self.lock:
+            self._remove_with_lock(name_or_uuid)
+
+    def new_root(self, name, uuid, generation=None):
+        """Adds a new root provider to the tree, returning its UUID.
+
+        :param name: The name of the new root provider
+        :param uuid: The UUID of the new root provider
+        :param generation: Generation to set for the new root provider
+        :returns: the UUID of the new provider
+        :raises: ValueError if a provider with the specified uuid already
+                 exists in the tree.
+        """
+
+        with self.lock:
+            exists = True
+            try:
+                self._find_with_lock(uuid)
+            except ValueError:
+                exists = False
+
+            if exists:
+                err = _("Provider %s already exists.")
+                raise ValueError(err % uuid)
+
+            p = _Provider(name, uuid=uuid, generation=generation)
+            self.roots.append(p)
+            return p.uuid
+
+    def _find_with_lock(self, name_or_uuid, return_root=False):
+        for root in self.roots:
+            found = root.find(name_or_uuid)
+            if found:
+                return root if return_root else found
+        raise ValueError(_("No such provider %s") % name_or_uuid)
+
+    def data(self, name_or_uuid):
+        """Return a point-in-time copy of the specified provider's data.
+
+        :param name_or_uuid: Either name or UUID of the resource provider whose
+                             data is to be returned.
+        :return: ProviderData object representing the specified provider.
+        :raises: ValueError if a provider with name_or_uuid was not found in
+                 the tree.
+        """
+        with self.lock:
+            return self._find_with_lock(name_or_uuid).data()
+
+    def exists(self, name_or_uuid):
+        """Given either a name or a UUID, return True if the tree contains the
+        provider, False otherwise.
+        """
+        with self.lock:
+            try:
+                self._find_with_lock(name_or_uuid)
+                return True
+            except ValueError:
+                return False
+
+    def new_child(self, name, parent, uuid=None, generation=None):
+        """Creates a new child provider with the given name and uuid under the
+        given parent.
+
+        :param name: The name of the new child provider
+        :param parent: Either name or UUID of the parent provider
+        :param uuid: The UUID of the new child provider
+        :param generation: Generation to set for the new child provider
+        :returns: the UUID of the new provider
+
+        :raises ValueError if a provider with the specified uuid or name
+                already exists; or if parent_uuid points to a nonexistent
+                provider.
+        """
+        with self.lock:
+            try:
+                self._find_with_lock(uuid or name)
+            except ValueError:
+                pass
+            else:
+                err = _("Provider %s already exists.")
+                raise ValueError(err % (uuid or name))
+
+            parent_node = self._find_with_lock(parent)
+            p = _Provider(name, uuid, generation, parent_node.uuid)
+            parent_node.add_child(p)
+            return p.uuid
+
+    def has_inventory(self, name_or_uuid):
+        """Returns True if the provider identified by name_or_uuid has any
+        inventory records at all.
+
+        :raises: ValueError if a provider with uuid was not found in the tree.
+        :param name_or_uuid: Either name or UUID of the resource provider
+        """
+        with self.lock:
+            p = self._find_with_lock(name_or_uuid)
+            return p.has_inventory()
+
+    def has_inventory_changed(self, name_or_uuid, inventory):
+        """Returns True if the supplied inventory is different for the provider
+        with the supplied name or UUID.
+
+        :raises: ValueError if a provider with name_or_uuid was not found in
+                 the tree.
+        :param name_or_uuid: Either name or UUID of the resource provider to
+                             query inventory for.
+        :param inventory: dict, keyed by resource class, of inventory
+                          information.
+        """
+        with self.lock:
+            provider = self._find_with_lock(name_or_uuid)
+            return provider.has_inventory_changed(inventory)
+
+    def update_inventory(self, name_or_uuid, inventory, generation=None):
+        """Given a name or UUID of a provider and a dict of inventory resource
+        records, update the provider's inventory and set the provider's
+        generation.
+
+        :returns: True if the inventory has changed.
+
+        :note: The provider's generation is always set to the supplied
+               generation, even if there were no changes to the inventory.
+
+        :raises: ValueError if a provider with name_or_uuid was not found in
+                 the tree.
+        :param name_or_uuid: Either name or UUID of the resource provider to
+                             update inventory for.
+        :param inventory: dict, keyed by resource class, of inventory
+                          information.
+        :param generation: The resource provider generation to set.  If not
+                           specified, the provider's generation is not changed.
+        """
+        with self.lock:
+            provider = self._find_with_lock(name_or_uuid)
+            return provider.update_inventory(inventory, generation)
+
+    def has_sharing_provider(self, resource_class):
+        """Returns whether the specified provider_tree contains any sharing
+        providers of inventory of the specified resource_class.
+        """
+        for rp_uuid in self.get_provider_uuids():
+            pdata = self.data(rp_uuid)
+            has_rc = resource_class in pdata.inventory
+            is_sharing = os_traits.MISC_SHARES_VIA_AGGREGATE in pdata.traits
+            if has_rc and is_sharing:
+                return True
+        return False
+
+    def has_traits(self, name_or_uuid, traits):
+        """Given a name or UUID of a provider, query whether that provider has
+        *all* of the specified traits.
+
+        :raises: ValueError if a provider with name_or_uuid was not found in
+                 the tree.
+        :param name_or_uuid: Either name or UUID of the resource provider to
+                             query for traits.
+        :param traits: Iterable of string trait names to search for.
+        :return: True if this provider has *all* of the specified traits; False
+                 if any of the specified traits are absent.  Returns True if
+                 the traits parameter is empty, even if the provider has no
+                 traits.
+        """
+        with self.lock:
+            provider = self._find_with_lock(name_or_uuid)
+            return provider.has_traits(traits)
+
+    def have_traits_changed(self, name_or_uuid, traits):
+        """Returns True if the specified traits list is different for the
+        provider with the specified name or UUID.
+
+        :raises: ValueError if a provider with name_or_uuid was not found in
+                 the tree.
+        :param name_or_uuid: Either name or UUID of the resource provider to
+                             query traits for.
+        :param traits: Iterable of string trait names to compare against the
+                       provider's traits.
+        """
+        with self.lock:
+            provider = self._find_with_lock(name_or_uuid)
+            return provider.have_traits_changed(traits)
+
+    def update_traits(self, name_or_uuid, traits, generation=None):
+        """Given a name or UUID of a provider and an iterable of string trait
+        names, update the provider's traits and set the provider's generation.
+
+        :returns: True if the traits list has changed.
+
+        :note: The provider's generation is always set to the supplied
+               generation, even if there were no changes to the traits.
+
+        :raises: ValueError if a provider with name_or_uuid was not found in
+                 the tree.
+        :param name_or_uuid: Either name or UUID of the resource provider to
+                             update traits for.
+        :param traits: Iterable of string trait names to set.
+        :param generation: The resource provider generation to set.  If None,
+                           the provider's generation is not changed.
+        """
+        with self.lock:
+            provider = self._find_with_lock(name_or_uuid)
+            return provider.update_traits(traits, generation=generation)
+
+    def add_traits(self, name_or_uuid, *traits):
+        """Set traits on a provider, without affecting existing traits.
+
+        :param name_or_uuid: The name or UUID of the provider whose traits are
+                             to be affected.
+        :param traits: String names of traits to be added.
+        """
+        if not traits:
+            return
+        with self.lock:
+            provider = self._find_with_lock(name_or_uuid)
+            final_traits = provider.traits | set(traits)
+            provider.update_traits(final_traits)
+
+    def remove_traits(self, name_or_uuid, *traits):
+        """Unset traits on a provider, without affecting other existing traits.
+
+        :param name_or_uuid: The name or UUID of the provider whose traits are
+                             to be affected.
+        :param traits: String names of traits to be removed.
+        """
+        if not traits:
+            return
+        with self.lock:
+            provider = self._find_with_lock(name_or_uuid)
+            final_traits = provider.traits - set(traits)
+            provider.update_traits(final_traits)
+
+    def in_aggregates(self, name_or_uuid, aggregates):
+        """Given a name or UUID of a provider, query whether that provider is a
+        member of *all* the specified aggregates.
+
+        :raises: ValueError if a provider with name_or_uuid was not found in
+                 the tree.
+        :param name_or_uuid: Either name or UUID of the resource provider to
+                             query for aggregates.
+        :param aggregates: Iterable of string aggregate UUIDs to search for.
+        :return: True if this provider is associated with *all* of the
+                 specified aggregates; False if any of the specified aggregates
+                 are absent.  Returns True if the aggregates parameter is
+                 empty, even if the provider has no aggregate associations.
+        """
+        with self.lock:
+            provider = self._find_with_lock(name_or_uuid)
+            return provider.in_aggregates(aggregates)
+
+    def have_aggregates_changed(self, name_or_uuid, aggregates):
+        """Returns True if the specified aggregates list is different for the
+        provider with the specified name or UUID.
+
+        :raises: ValueError if a provider with name_or_uuid was not found in
+                 the tree.
+        :param name_or_uuid: Either name or UUID of the resource provider to
+                             query aggregates for.
+        :param aggregates: Iterable of string aggregate UUIDs to compare
+                           against the provider's aggregates.
+        """
+        with self.lock:
+            provider = self._find_with_lock(name_or_uuid)
+            return provider.have_aggregates_changed(aggregates)
+
+    def update_aggregates(self, name_or_uuid, aggregates, generation=None):
+        """Given a name or UUID of a provider and an iterable of string
+        aggregate UUIDs, update the provider's aggregates and set the
+        provider's generation.
+
+        :returns: True if the aggregates list has changed.
+
+        :note: The provider's generation is always set to the supplied
+               generation, even if there were no changes to the aggregates.
+
+        :raises: ValueError if a provider with name_or_uuid was not found in
+                 the tree.
+        :param name_or_uuid: Either name or UUID of the resource provider to
+                             update aggregates for.
+        :param aggregates: Iterable of string aggregate UUIDs to set.
+        :param generation: The resource provider generation to set.  If None,
+                           the provider's generation is not changed.
+        """
+        with self.lock:
+            provider = self._find_with_lock(name_or_uuid)
+            return provider.update_aggregates(aggregates,
+                                              generation=generation)
+
+    def add_aggregates(self, name_or_uuid, *aggregates):
+        """Set aggregates on a provider, without affecting existing aggregates.
+
+        :param name_or_uuid: The name or UUID of the provider whose aggregates
+                             are to be affected.
+        :param aggregates: String UUIDs of aggregates to be added.
+        """
+        with self.lock:
+            provider = self._find_with_lock(name_or_uuid)
+            final_aggs = provider.aggregates | set(aggregates)
+            provider.update_aggregates(final_aggs)
+
+    def remove_aggregates(self, name_or_uuid, *aggregates):
+        """Unset aggregates on a provider, without affecting other existing
+        aggregates.
+
+        :param name_or_uuid: The name or UUID of the provider whose aggregates
+                             are to be affected.
+        :param aggregates: String UUIDs of aggregates to be removed.
+        """
+        with self.lock:
+            provider = self._find_with_lock(name_or_uuid)
+            final_aggs = provider.aggregates - set(aggregates)
+            provider.update_aggregates(final_aggs)

zun/conf/__init__.py

@@ -29,6 +29,7 @@ from zun.conf import network
 from zun.conf import neutron_client
 from zun.conf import path
 from zun.conf import pci
+from zun.conf import placement_client
 from zun.conf import profiler
 from zun.conf import quota
 from zun.conf import scheduler
@@ -65,3 +66,4 @@ cinder_client.register_opts(CONF)
 netconf.register_opts(CONF)
 availability_zone.register_opts(CONF)
 utils.register_opts(CONF)
+placement_client.register_opts(CONF)

zun/conf/compute.py

@@ -29,6 +29,25 @@ compute_opts = [
         'enable_cpu_pinning',
         default=False,
         help='allow the container with cpu_policy is dedicated'),
+    cfg.IntOpt(
+        'resource_provider_association_refresh',
+        default=300,
+        min=0,
+        mutable=True,
+        # TODO(efried): Provide more/better explanation of what this option is
+        # all about. Reference bug(s). Unless we're just going to remove it.
+        help="""
+Interval for updating zun-compute-side cache of the compute node resource
+provider's inventories, aggregates, and traits.
+This option specifies the number of seconds between attempts to update a
+provider's inventories, aggregates and traits in the local cache of the compute
+node.
+A value of zero disables cache refresh completely.
+The cache can be cleared manually at any time by sending SIGHUP to the compute
+process, causing it to be repopulated the next time the data is accessed.
+Possible values:
+* Any positive integer in seconds, or zero to disable refresh.
+"""),
 ]
 
 service_opts = [

zun/conf/placement_client.py

@@ -0,0 +1,53 @@
+#    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.
+
+from oslo_config import cfg
+
+
+placement_group = cfg.OptGroup(
+    name='placement_client',
+    title='Placement Service Options',
+    help="Configuration options for connecting to the placement API service")
+
+common_security_opts = [
+    cfg.StrOpt('ca_file',
+               help='Optional CA cert file to use in SSL connections.'),
+    cfg.StrOpt('cert_file',
+               help='Optional PEM-formatted certificate chain file.'),
+    cfg.StrOpt('key_file',
+               help='Optional PEM-formatted file that contains the '
+                    'private key.'),
+    cfg.BoolOpt('insecure',
+                default=False,
+                help="If set, then the server's certificate will not "
+                     "be verified.")]
+
+placement_client_opts = [
+    cfg.StrOpt('region_name',
+               help='Region in Identity service catalog to use for '
+                    'communication with the OpenStack service.'),
+    cfg.StrOpt('endpoint_type',
+               default='publicURL',
+               help='Type of endpoint in Identity service catalog to use '
+                    'for communication with the OpenStack service.')]
+
+
+ALL_OPTS = (placement_client_opts + common_security_opts)
+
+
+def register_opts(conf):
+    conf.register_group(placement_group)
+    conf.register_opts(ALL_OPTS, group=placement_group)
+
+
+def list_opts():
+    return {placement_group: ALL_OPTS}

zun/conf/scheduler.py

@@ -92,6 +92,25 @@ Related options:
 * All of the filters in this option *must* be present in the
   'scheduler_available_filters' option, or a SchedulerHostFilterNotFound
   exception will be raised.
+"""),
+    cfg.IntOpt("max_placement_results",
+               default=1000,
+               min=1,
+               help="""
+This setting determines the maximum limit on results received from the
+placement service during a scheduling operation. It effectively limits
+the number of hosts that may be considered for scheduling requests that
+match a large number of candidates.
+
+A value of 1 (the minimum) will effectively defer scheduling to the placement
+service strictly on "will it fit" grounds. A higher value will put an upper
+cap on the number of results the scheduler will consider during the filtering
+and weighing process. Large deployments may need to set this lower than the
+total number of hosts available to limit memory consumption, network traffic,
+etc. of the scheduler.
+
+This option is only used by the FilterScheduler; if you use a different
+scheduler, this option has no effect.
 """),
 ]
 

zun/objects/__init__.py

@@ -23,6 +23,7 @@ from zun.objects import pci_device_pool
 from zun.objects import quota
 from zun.objects import quota_class
 from zun.objects import registry
+from zun.objects import request_group
 from zun.objects import resource_class
 from zun.objects import resource_provider
 from zun.objects import volume
@@ -54,6 +55,7 @@ ContainerAction = container_action.ContainerAction
 ContainerActionEvent = container_action.ContainerActionEvent
 ExecInstance = exec_instance.ExecInstance
 Registry = registry.Registry
+RequestGroup = request_group.RequestGroup
 
 __all__ = (
     'Container',
@@ -79,4 +81,5 @@ __all__ = (
     'ContainerActionEvent',
     'ExecInstance',
     'Registry',
+    'RequestGroup',
 )

zun/objects/fields.py

@@ -83,6 +83,14 @@ class JsonField(fields.AutoTypedField):
     AUTO_TYPE = Json()
 
 
+class SetOfStringsField(fields.AutoTypedField):
+    AUTO_TYPE = fields.Set(fields.String())
+
+
+class ListOfListsOfStringsField(fields.AutoTypedField):
+    AUTO_TYPE = fields.List(fields.List(fields.String()))
+
+
 class ResourceClass(fields.Enum):
     ALL = consts.RESOURCE_CLASSES
 
@@ -119,8 +127,8 @@ class PciDeviceType(BaseZunEnum):
 
 
 class PciDeviceTypeField(fields.BaseEnumField):
-        AUTO_TYPE = PciDeviceType()
+    AUTO_TYPE = PciDeviceType()
 
 
 class PciDeviceStatusField(fields.BaseEnumField):
-        AUTO_TYPE = PciDeviceStatus()
+    AUTO_TYPE = PciDeviceStatus()

zun/objects/request_group.py

@@ -0,0 +1,48 @@
+#    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.
+
+from oslo_versionedobjects import fields
+
+from zun.objects import base
+from zun.objects import fields as zun_fields
+
+
+@base.ZunObjectRegistry.register
+class RequestGroup(base.ZunPersistentObject, base.ZunObject):
+    # Version 1.0: Initial version
+    VERSION = '1.0'
+
+    fields = {
+        'use_same_provider': fields.BooleanField(default=True),
+        'resources': fields.DictOfIntegersField(default={}),
+        'required_traits': zun_fields.SetOfStringsField(default=set()),
+        'forbidden_traits': zun_fields.SetOfStringsField(default=set()),
+        # The aggregates field has a form of
+        #     [[aggregate_UUID1],
+        #      [aggregate_UUID2, aggregate_UUID3]]
+        # meaning that the request should be fulfilled from an RP that is a
+        # member of the aggregate aggregate_UUID1 and member of the aggregate
+        # aggregate_UUID2 or aggregate_UUID3 .
+        'aggregates': zun_fields.ListOfListsOfStringsField(default=[]),
+        # The entity the request is coming from (e.g. the Neutron port uuid)
+        # which may not always be a UUID.
+        'requester_id': fields.StringField(nullable=True, default=None),
+        # The resource provider UUIDs that together fulfill the request
+        # NOTE(gibi): this can be more than one if this is the unnumbered
+        # request group (i.e. use_same_provider=False)
+        'provider_uuids': fields.ListOfUUIDField(default=[]),
+        'in_tree': fields.UUIDField(nullable=True, default=None),
+    }
+
+    def __init__(self, context=None, **kwargs):
+        super(RequestGroup, self).__init__(context=context, **kwargs)
+        self.obj_set_defaults()

zun/scheduler/utils.py

@@ -0,0 +1,282 @@
+# All Rights Reserved.
+#
+#    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.
+
+"""Utility methods for scheduling."""
+
+import collections
+import re
+
+import os_resource_classes as orc
+from oslo_log import log as logging
+from six.moves.urllib import parse
+
+import zun.conf
+from zun import objects
+
+
+LOG = logging.getLogger(__name__)
+
+CONF = zun.conf.CONF
+
+
+class ResourceRequest(object):
+    """Presents a granular resource request via RequestGroup instances."""
+    # extra_specs-specific consts
+    XS_RES_PREFIX = 'resources'
+    XS_TRAIT_PREFIX = 'trait'
+    # Regex patterns for numbered or un-numbered resources/trait keys
+    XS_KEYPAT = re.compile(r"^(%s)([1-9][0-9]*)?:(.*)$" %
+                           '|'.join((XS_RES_PREFIX, XS_TRAIT_PREFIX)))
+
+    def __init__(self):
+        # { ident: RequestGroup }
+        self._rg_by_id = {}
+        self._group_policy = None
+        # Default to the configured limit but _limit can be
+        # set to None to indicate "no limit".
+        self._limit = CONF.scheduler.max_placement_results
+
+    def __str__(self):
+        return ', '.join(sorted(
+            list(str(rg) for rg in list(self._rg_by_id.values()))))
+
+    @property
+    def group_policy(self):
+        return self._group_policy
+
+    @group_policy.setter
+    def group_policy(self, value):
+        self._group_policy = value
+
+    def get_request_group(self, ident):
+        if ident not in self._rg_by_id:
+            rq_grp = objects.RequestGroup(use_same_provider=bool(ident))
+            self._rg_by_id[ident] = rq_grp
+        return self._rg_by_id[ident]
+
+    def add_request_group(self, request_group):
+        """Inserts the existing group with a unique integer id
+
+        This function can ensure unique ids by using bigger
+        ids than the maximum of existing ids.
+
+        :param request_group: the RequestGroup to be added
+        """
+        # NOTE(gibi) [0] just here to always have a defined maximum
+        group_idents = [0] + [int(ident) for ident in self._rg_by_id if ident]
+        ident = max(group_idents) + 1
+        self._rg_by_id[ident] = request_group
+
+    def _add_resource(self, groupid, rclass, amount):
+        # Validate the class.
+        if not (rclass.startswith(orc.CUSTOM_NAMESPACE) or
+                rclass in orc.STANDARDS):
+            LOG.warning(
+                "Received an invalid ResourceClass '%(key)s' in extra_specs.",
+                {"key": rclass})
+            return
+        # val represents the amount.  Convert to int, or warn and skip.
+        try:
+            amount = int(amount)
+            if amount < 0:
+                raise ValueError()
+        except ValueError:
+            LOG.warning(
+                "Resource amounts must be nonnegative integers. Received "
+                "'%(val)s' for key resources%(groupid)s.",
+                {"groupid": groupid or '', "val": amount})
+            return
+        self.get_request_group(groupid).resources[rclass] = amount
+
+    def _add_trait(self, groupid, trait_name, trait_type):
+        # Currently the only valid values for a trait entry are 'required'
+        # and 'forbidden'
+        trait_vals = ('required', 'forbidden')
+        if trait_type == 'required':
+            self.get_request_group(groupid).required_traits.add(trait_name)
+        elif trait_type == 'forbidden':
+            self.get_request_group(groupid).forbidden_traits.add(trait_name)
+        else:
+            LOG.warning(
+                "Only (%(tvals)s) traits are supported. Received '%(val)s' "
+                "for key trait%(groupid)s.",
+                {"tvals": ', '.join(trait_vals), "groupid": groupid or '',
+                 "val": trait_type})
+        return
+
+    def _add_group_policy(self, policy):
+        # The only valid values for group_policy are 'none' and 'isolate'.
+        if policy not in ('none', 'isolate'):
+            LOG.warning(
+                "Invalid group_policy '%s'. Valid values are 'none' and "
+                "'isolate'.", policy)
+            return
+        self._group_policy = policy
+
+    @classmethod
+    def from_extra_specs(cls, extra_specs, req=None):
+        """Processes resources and traits in numbered groupings in extra_specs.
+
+        Examines extra_specs for items of the following forms:
+            "resources:$RESOURCE_CLASS": $AMOUNT
+            "resources$N:$RESOURCE_CLASS": $AMOUNT
+            "trait:$TRAIT_NAME": "required"
+            "trait$N:$TRAIT_NAME": "required"
+
+        Does *not* yet handle member_of[$N].
+
+        :param extra_specs: The extra_specs dict.
+        :param req: the ResourceRequest object to add the requirements to or
+               None to create a new ResourceRequest
+        :return: A ResourceRequest object representing the resources and
+                 required traits in the extra_specs.
+        """
+        # TODO(efried): Handle member_of[$N], which will need to be reconciled
+        # with destination.aggregates handling in resources_from_request_spec
+
+        if req is not None:
+            ret = req
+        else:
+            ret = cls()
+
+        for key, val in extra_specs.items():
+            if key == 'group_policy':
+                ret._add_group_policy(val)
+                continue
+
+            match = cls.XS_KEYPAT.match(key)
+            if not match:
+                continue
+
+            # 'prefix' is 'resources' or 'trait'
+            # 'suffix' is $N or None
+            # 'name' is either the resource class name or the trait name.
+            prefix, suffix, name = match.groups()
+
+            # Process "resources[$N]"
+            if prefix == cls.XS_RES_PREFIX:
+                ret._add_resource(suffix, name, val)
+
+            # Process "trait[$N]"
+            elif prefix == cls.XS_TRAIT_PREFIX:
+                ret._add_trait(suffix, name, val)
+
+        return ret
+
+    def resource_groups(self):
+        for rg in self._rg_by_id.values():
+            yield rg.resources
+
+    def get_num_of_numbered_groups(self):
+        return len([ident for ident in self._rg_by_id.keys()
+                    if ident is not None])
+
+    def merged_resources(self, resources=None):
+        """Returns a merge of {resource_class: amount} for all resource groups.
+
+        Amounts of the same resource class from different groups are added
+        together.
+
+        :param resources: A flat dict of {resource_class: amount}.  If
+                          specified, the resources therein are folded
+                          into the return dict, such that any resource
+                          in resources is included only if that
+                          resource class does not exist elsewhere in the
+                          merged ResourceRequest.
+        :return: A dict of the form {resource_class: amount}
+        """
+        ret = collections.defaultdict(lambda: 0)
+        for resource_dict in self.resource_groups():
+            for resource_class, amount in resource_dict.items():
+                ret[resource_class] += amount
+        if resources:
+            for resource_class, amount in resources.items():
+                # If it's in there - even if zero - ignore the one from the
+                # flavor.
+                if resource_class not in ret:
+                    ret[resource_class] = amount
+            # Now strip zeros.  This has to be done after the above - we can't
+            # use strip_zeros :(
+            ret = {rc: amt for rc, amt in ret.items() if amt}
+        return dict(ret)
+
+    def _clean_empties(self):
+        """Get rid of any empty ResourceGroup instances."""
+        for ident, rg in list(self._rg_by_id.items()):
+            if not any((rg.resources, rg.required_traits,
+                        rg.forbidden_traits)):
+                self._rg_by_id.pop(ident)
+
+    def strip_zeros(self):
+        """Remove any resources whose amounts are zero."""
+        for resource_dict in self.resource_groups():
+            for rclass in list(resource_dict):
+                if resource_dict[rclass] == 0:
+                    resource_dict.pop(rclass)
+        self._clean_empties()
+
+    def to_querystring(self):
+        """Produce a querystring of the form expected by
+        GET /allocation_candidates.
+        """
+        # TODO(gibi): We have a RequestGroup OVO so we can move this to that
+        # class as a member function.
+        # NOTE(efried): The sorting herein is not necessary for the API; it is
+        # to make testing easier and logging/debugging predictable.
+        def to_queryparams(request_group, suffix):
+            res = request_group.resources
+            required_traits = request_group.required_traits
+            forbidden_traits = request_group.forbidden_traits
+            aggregates = request_group.aggregates
+            in_tree = request_group.in_tree
+
+            resource_query = ",".join(
+                sorted("%s:%s" % (rc, amount)
+                       for (rc, amount) in res.items()))
+            qs_params = [('resources%s' % suffix, resource_query)]
+
+            # Assemble required and forbidden traits, allowing for either/both
+            # to be empty.
+            required_val = ','.join(
+                sorted(required_traits) +
+                ['!%s' % ft for ft in sorted(forbidden_traits)])
+            if required_val:
+                qs_params.append(('required%s' % suffix, required_val))
+            if aggregates:
+                aggs = []
+                # member_ofN is a list of lists.  We need a tuple of
+                # ('member_ofN', 'in:uuid,uuid,...') for each inner list.
+                for agglist in aggregates:
+                    aggs.append(('member_of%s' % suffix,
+                                 'in:' + ','.join(sorted(agglist))))
+                qs_params.extend(sorted(aggs))
+            if in_tree:
+                qs_params.append(('in_tree%s' % suffix, in_tree))
+            return qs_params
+
+        if self._limit is not None:
+            qparams = [('limit', self._limit)]
+        else:
+            qparams = []
+        if self._group_policy is not None:
+            qparams.append(('group_policy', self._group_policy))
+
+        for ident, rg in self._rg_by_id.items():
+            # [('resourcesN', 'rclass:amount,rclass:amount,...'),
+            #  ('requiredN', 'trait_name,!trait_name,...'),
+            #  ('member_ofN', 'in:uuid,uuid,...'),
+            #  ('member_ofN', 'in:uuid,uuid,...')]
+            qparams.extend(to_queryparams(rg, ident or ''))
+
+        return parse.urlencode(sorted(qparams))

zun/tests/unit/compute/test_provider_tree.py

@@ -0,0 +1,692 @@
+# 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.
+from oslo_utils.fixture import uuidsentinel as uuids
+
+from zun.common import context
+from zun.compute import provider_tree
+from zun.tests import base
+from zun.tests.unit.objects import utils
+
+
+class TestProviderTree(base.TestCase):
+
+    def setUp(self):
+        super(TestProviderTree, self).setUp()
+        self.context = context.get_admin_context()
+        self.compute_node1 = utils.get_test_compute_node(
+            self.context, uuid=uuids.cn1, hostname='compute-node-1')
+        self.compute_node2 = utils.get_test_compute_node(
+            self.context, uuid=uuids.cn2, hostname='compute-node-2')
+        self.compute_nodes = [self.compute_node1, self.compute_node2]
+
+    def _pt_with_cns(self):
+        pt = provider_tree.ProviderTree()
+        for cn in self.compute_nodes:
+            pt.new_root(cn.hostname, cn.uuid, generation=0)
+        return pt
+
+    def test_tree_ops(self):
+        cn1 = self.compute_node1
+        cn2 = self.compute_node2
+        pt = self._pt_with_cns()
+
+        self.assertRaises(
+            ValueError,
+            pt.new_root,
+            cn1.hostname,
+            cn1.uuid,
+        )
+
+        self.assertTrue(pt.exists(cn1.uuid))
+        self.assertTrue(pt.exists(cn1.hostname))
+        self.assertFalse(pt.exists(uuids.non_existing_rp))
+        self.assertFalse(pt.exists('noexist'))
+
+        self.assertEqual([cn1.uuid],
+                         pt.get_provider_uuids(name_or_uuid=cn1.uuid))
+        # Same with ..._in_tree
+        self.assertEqual([cn1.uuid], pt.get_provider_uuids_in_tree(cn1.uuid))
+        self.assertEqual(set([cn1.uuid, cn2.uuid]),
+                         set(pt.get_provider_uuids()))
+
+        numa_cell0_uuid = pt.new_child('numa_cell0', cn1.uuid)
+        numa_cell1_uuid = pt.new_child('numa_cell1', cn1.hostname)
+
+        self.assertEqual(cn1.uuid, pt.data(numa_cell1_uuid).parent_uuid)
+
+        self.assertTrue(pt.exists(numa_cell0_uuid))
+        self.assertTrue(pt.exists('numa_cell0'))
+
+        self.assertTrue(pt.exists(numa_cell1_uuid))
+        self.assertTrue(pt.exists('numa_cell1'))
+
+        pf1_cell0_uuid = pt.new_child('pf1_cell0', numa_cell0_uuid)
+        self.assertTrue(pt.exists(pf1_cell0_uuid))
+        self.assertTrue(pt.exists('pf1_cell0'))
+
+        # Now we've got a 3-level tree under cn1 - check provider UUIDs again
+        all_cn1 = [cn1.uuid, numa_cell0_uuid, pf1_cell0_uuid, numa_cell1_uuid]
+        self.assertEqual(
+            set(all_cn1),
+            set(pt.get_provider_uuids(name_or_uuid=cn1.uuid)))
+        # Same with ..._in_tree if we're asking for the root
+        self.assertEqual(
+            set(all_cn1),
+            set(pt.get_provider_uuids_in_tree(cn1.uuid)))
+        # Asking for a subtree.
+        self.assertEqual(
+            [numa_cell0_uuid, pf1_cell0_uuid],
+            pt.get_provider_uuids(name_or_uuid=numa_cell0_uuid))
+        # With ..._in_tree, get the whole tree no matter which we specify.
+        for node in all_cn1:
+            self.assertEqual(set(all_cn1), set(pt.get_provider_uuids_in_tree(
+                node)))
+        # With no provider specified, get everything
+        self.assertEqual(
+            set([cn1.uuid, cn2.uuid, numa_cell0_uuid, pf1_cell0_uuid,
+                 numa_cell1_uuid]),
+            set(pt.get_provider_uuids()))
+
+        self.assertRaises(
+            ValueError,
+            pt.new_child,
+            'pf1_cell0',
+            uuids.non_existing_rp,
+        )
+
+        # Fail attempting to add a child that already exists in the tree
+        # Existing provider is a child; search by name
+        self.assertRaises(ValueError, pt.new_child, 'numa_cell0', cn1.uuid)
+        # Existing provider is a root; search by UUID
+        self.assertRaises(ValueError, pt.new_child, cn1.uuid, cn2.uuid)
+
+        # Test data().
+        # Root, by UUID
+        cn1_snap = pt.data(cn1.uuid)
+        # Fields were faithfully copied
+        self.assertEqual(cn1.uuid, cn1_snap.uuid)
+        self.assertEqual(cn1.hostname, cn1_snap.name)
+        self.assertIsNone(cn1_snap.parent_uuid)
+        self.assertEqual({}, cn1_snap.inventory)
+        self.assertEqual(set(), cn1_snap.traits)
+        self.assertEqual(set(), cn1_snap.aggregates)
+        # Validate read-only-ness
+        self.assertRaises(AttributeError, setattr, cn1_snap, 'name', 'foo')
+
+        cn3 = utils.get_test_compute_node(
+            self.context, uuid=uuids.cn3, hostname='compute-node-3')
+        self.assertFalse(pt.exists(cn3.uuid))
+        self.assertFalse(pt.exists(cn3.hostname))
+        pt.new_root(cn3.hostname, cn3.uuid)
+
+        self.assertTrue(pt.exists(cn3.uuid))
+        self.assertTrue(pt.exists(cn3.hostname))
+
+        self.assertRaises(
+            ValueError,
+            pt.new_root,
+            cn3.hostname,
+            cn3.uuid,
+        )
+
+        self.assertRaises(
+            ValueError,
+            pt.remove,
+            uuids.non_existing_rp,
+        )
+
+        pt.remove(numa_cell1_uuid)
+        self.assertFalse(pt.exists(numa_cell1_uuid))
+        self.assertTrue(pt.exists(pf1_cell0_uuid))
+        self.assertTrue(pt.exists(numa_cell0_uuid))
+        self.assertTrue(pt.exists(uuids.cn1))
+
+        # Now remove the root and check that children no longer exist
+        pt.remove(uuids.cn1)
+        self.assertFalse(pt.exists(pf1_cell0_uuid))
+        self.assertFalse(pt.exists(numa_cell0_uuid))
+        self.assertFalse(pt.exists(uuids.cn1))
+
+    def test_populate_from_iterable_empty(self):
+        pt = provider_tree.ProviderTree()
+        # Empty list is a no-op
+        pt.populate_from_iterable([])
+        self.assertEqual([], pt.get_provider_uuids())
+
+    def test_populate_from_iterable_error_orphan_cycle(self):
+        pt = provider_tree.ProviderTree()
+
+        # Error trying to populate with an orphan
+        grandchild1_1 = {
+            'uuid': uuids.grandchild1_1,
+            'name': 'grandchild1_1',
+            'generation': 11,
+            'parent_provider_uuid': uuids.child1,
+        }
+
+        self.assertRaises(ValueError,
+                          pt.populate_from_iterable, [grandchild1_1])
+
+        # Create a cycle so there are no orphans, but no path to a root
+        cycle = {
+            'uuid': uuids.child1,
+            'name': 'child1',
+            'generation': 1,
+            # There's a country song about this
+            'parent_provider_uuid': uuids.grandchild1_1,
+        }
+
+        self.assertRaises(ValueError,
+                          pt.populate_from_iterable, [grandchild1_1, cycle])
+
+    def test_populate_from_iterable_complex(self):
+        # root
+        #   +-> child1
+        #   |      +-> grandchild1_2
+        #   |             +-> ggc1_2_1
+        #   |             +-> ggc1_2_2
+        #   |             +-> ggc1_2_3
+        #   +-> child2
+        # another_root
+        pt = provider_tree.ProviderTree()
+        plist = [
+            {
+                'uuid': uuids.root,
+                'name': 'root',
+                'generation': 0,
+            },
+            {
+                'uuid': uuids.child1,
+                'name': 'child1',
+                'generation': 1,
+                'parent_provider_uuid': uuids.root,
+            },
+            {
+                'uuid': uuids.child2,
+                'name': 'child2',
+                'generation': 2,
+                'parent_provider_uuid': uuids.root,
+            },
+            {
+                'uuid': uuids.grandchild1_2,
+                'name': 'grandchild1_2',
+                'generation': 12,
+                'parent_provider_uuid': uuids.child1,
+            },
+            {
+                'uuid': uuids.ggc1_2_1,
+                'name': 'ggc1_2_1',
+                'generation': 121,
+                'parent_provider_uuid': uuids.grandchild1_2,
+            },
+            {
+                'uuid': uuids.ggc1_2_2,
+                'name': 'ggc1_2_2',
+                'generation': 122,
+                'parent_provider_uuid': uuids.grandchild1_2,
+            },
+            {
+                'uuid': uuids.ggc1_2_3,
+                'name': 'ggc1_2_3',
+                'generation': 123,
+                'parent_provider_uuid': uuids.grandchild1_2,
+            },
+            {
+                'uuid': uuids.another_root,
+                'name': 'another_root',
+                'generation': 911,
+            },
+        ]
+        pt.populate_from_iterable(plist)
+
+        def validate_root(expected_uuids):
+            # Make sure we have all and only the expected providers
+            self.assertEqual(expected_uuids, set(pt.get_provider_uuids()))
+            # Now make sure they're in the right hierarchy.  Cheat: get the
+            # actual _Provider to make it easier to walk the tree (ProviderData
+            # doesn't include children).
+            root = pt._find_with_lock(uuids.root)
+            self.assertEqual(uuids.root, root.uuid)
+            self.assertEqual('root', root.name)
+            self.assertEqual(0, root.generation)
+            self.assertIsNone(root.parent_uuid)
+            self.assertEqual(2, len(list(root.children)))
+            for child in root.children.values():
+                self.assertTrue(child.name.startswith('child'))
+                if child.name == 'child1':
+                    if uuids.grandchild1_1 in expected_uuids:
+                        self.assertEqual(2, len(list(child.children)))
+                    else:
+                        self.assertEqual(1, len(list(child.children)))
+                    for grandchild in child.children.values():
+                        self.assertTrue(grandchild.name.startswith(
+                            'grandchild1_'))
+                        if grandchild.name == 'grandchild1_1':
+                            self.assertEqual(0, len(list(grandchild.children)))
+                        if grandchild.name == 'grandchild1_2':
+                            self.assertEqual(3, len(list(grandchild.children)))
+                            for ggc in grandchild.children.values():
+                                self.assertTrue(ggc.name.startswith('ggc1_2_'))
+            another_root = pt._find_with_lock(uuids.another_root)
+            self.assertEqual(uuids.another_root, another_root.uuid)
+            self.assertEqual('another_root', another_root.name)
+            self.assertEqual(911, another_root.generation)
+            self.assertIsNone(another_root.parent_uuid)
+            self.assertEqual(0, len(list(another_root.children)))
+            if uuids.new_root in expected_uuids:
+                new_root = pt._find_with_lock(uuids.new_root)
+                self.assertEqual(uuids.new_root, new_root.uuid)
+                self.assertEqual('new_root', new_root.name)
+                self.assertEqual(42, new_root.generation)
+                self.assertIsNone(new_root.parent_uuid)
+                self.assertEqual(0, len(list(new_root.children)))
+
+        expected_uuids = set([
+            uuids.root, uuids.child1, uuids.child2, uuids.grandchild1_2,
+            uuids.ggc1_2_1, uuids.ggc1_2_2, uuids.ggc1_2_3,
+            uuids.another_root])
+
+        validate_root(expected_uuids)
+
+        # Merge an orphan - still an error
+        orphan = {
+            'uuid': uuids.orphan,
+            'name': 'orphan',
+            'generation': 86,
+            'parent_provider_uuid': uuids.mystery,
+        }
+        self.assertRaises(ValueError, pt.populate_from_iterable, [orphan])
+
+        # And the tree didn't change
+        validate_root(expected_uuids)
+
+        # Merge a list with a new grandchild and a new root
+        plist = [
+            {
+                'uuid': uuids.grandchild1_1,
+                'name': 'grandchild1_1',
+                'generation': 11,
+                'parent_provider_uuid': uuids.child1,
+            },
+            {
+                'uuid': uuids.new_root,
+                'name': 'new_root',
+                'generation': 42,
+            },
+        ]
+        pt.populate_from_iterable(plist)
+
+        expected_uuids |= set([uuids.grandchild1_1, uuids.new_root])
+
+        validate_root(expected_uuids)
+
+        # Merge an empty list - still a no-op
+        pt.populate_from_iterable([])
+        validate_root(expected_uuids)
+
+        # Since we have a complex tree, test the ordering of get_provider_uuids
+        # We can't predict the order of siblings, or where nephews will appear
+        # relative to their uncles, but we can guarantee that any given child
+        # always comes after its parent (and by extension, its ancestors too).
+        puuids = pt.get_provider_uuids()
+        for desc in (uuids.child1, uuids.child2):
+            self.assertGreater(puuids.index(desc), puuids.index(uuids.root))
+        for desc in (uuids.grandchild1_1, uuids.grandchild1_2):
+            self.assertGreater(puuids.index(desc), puuids.index(uuids.child1))
+        for desc in (uuids.ggc1_2_1, uuids.ggc1_2_2, uuids.ggc1_2_3):
+            self.assertGreater(
+                puuids.index(desc), puuids.index(uuids.grandchild1_2))
+
+    def test_populate_from_iterable_with_root_update(self):
+        # Ensure we can update hierarchies, including adding children, in a
+        # tree that's already populated.  This tests the case where a given
+        # provider exists both in the tree and in the input.  We must replace
+        # that provider *before* we inject its descendants; otherwise the
+        # descendants will be lost.  Note that this test case is not 100%
+        # reliable, as we can't predict the order over which hashed values are
+        # iterated.
+
+        pt = provider_tree.ProviderTree()
+
+        # Let's create a root
+        plist = [
+            {
+                'uuid': uuids.root,
+                'name': 'root',
+                'generation': 0,
+            },
+        ]
+        pt.populate_from_iterable(plist)
+        expected_uuids = [uuids.root]
+        self.assertEqual(expected_uuids, pt.get_provider_uuids())
+
+        # Let's add a child updating the name and generation for the root.
+        # root
+        #   +-> child1
+        plist = [
+            {
+                'uuid': uuids.root,
+                'name': 'root_with_new_name',
+                'generation': 1,
+            },
+            {
+                'uuid': uuids.child1,
+                'name': 'child1',
+                'generation': 1,
+                'parent_provider_uuid': uuids.root,
+            },
+        ]
+        pt.populate_from_iterable(plist)
+        expected_uuids = [uuids.root, uuids.child1]
+        self.assertEqual(expected_uuids, pt.get_provider_uuids())
+
+    def test_populate_from_iterable_disown_grandchild(self):
+        # Start with:
+        # root
+        #   +-> child
+        #   |      +-> grandchild
+        # Then send in [child] and grandchild should disappear.
+        child = {
+            'uuid': uuids.child,
+            'name': 'child',
+            'generation': 1,
+            'parent_provider_uuid': uuids.root,
+        }
+        pt = provider_tree.ProviderTree()
+        plist = [
+            {
+                'uuid': uuids.root,
+                'name': 'root',
+                'generation': 0,
+            },
+            child,
+            {
+                'uuid': uuids.grandchild,
+                'name': 'grandchild',
+                'generation': 2,
+                'parent_provider_uuid': uuids.child,
+            },
+        ]
+        pt.populate_from_iterable(plist)
+        self.assertEqual([uuids.root, uuids.child, uuids.grandchild],
+                         pt.get_provider_uuids())
+        self.assertTrue(pt.exists(uuids.grandchild))
+        pt.populate_from_iterable([child])
+        self.assertEqual([uuids.root, uuids.child], pt.get_provider_uuids())
+        self.assertFalse(pt.exists(uuids.grandchild))
+
+    def test_has_inventory_changed_no_existing_rp(self):
+        pt = self._pt_with_cns()
+        self.assertRaises(
+            ValueError,
+            pt.has_inventory_changed,
+            uuids.non_existing_rp,
+            {}
+        )
+
+    def test_update_inventory_no_existing_rp(self):
+        pt = self._pt_with_cns()
+        self.assertRaises(
+            ValueError,
+            pt.update_inventory,
+            uuids.non_existing_rp,
+            {},
+        )
+
+    def test_has_inventory_changed(self):
+        cn = self.compute_node1
+        pt = self._pt_with_cns()
+        rp_gen = 1
+
+        cn_inv = {
+            'VCPU': {
+                'total': 8,
+                'min_unit': 1,
+                'max_unit': 8,
+                'step_size': 1,
+                'allocation_ratio': 16.0,
+            },
+            'MEMORY_MB': {
+                'total': 1024,
+                'reserved': 512,
+                'min_unit': 64,
+                'max_unit': 1024,
+                'step_size': 64,
+                'allocation_ratio': 1.5,
+            },
+            'DISK_GB': {
+                'total': 1000,
+                'reserved': 100,
+                'min_unit': 10,
+                'max_unit': 1000,
+                'step_size': 10,
+                'allocation_ratio': 1.0,
+            },
+        }
+        self.assertTrue(pt.has_inventory_changed(cn.uuid, cn_inv))
+        self.assertTrue(pt.update_inventory(cn.uuid, cn_inv,
+                                            generation=rp_gen))
+
+        # Updating with the same inventory info should return False
+        self.assertFalse(pt.has_inventory_changed(cn.uuid, cn_inv))
+        self.assertFalse(pt.update_inventory(cn.uuid, cn_inv,
+                                             generation=rp_gen))
+
+        # A data-grab's inventory should be "equal" to the original
+        cndata = pt.data(cn.uuid)
+        self.assertFalse(pt.has_inventory_changed(cn.uuid, cndata.inventory))
+
+        cn_inv['VCPU']['total'] = 6
+        self.assertTrue(pt.has_inventory_changed(cn.uuid, cn_inv))
+        self.assertTrue(pt.update_inventory(cn.uuid, cn_inv,
+                                            generation=rp_gen))
+
+        # The data() result was not affected; now the tree's copy is different
+        self.assertTrue(pt.has_inventory_changed(cn.uuid, cndata.inventory))
+
+        self.assertFalse(pt.has_inventory_changed(cn.uuid, cn_inv))
+        self.assertFalse(pt.update_inventory(cn.uuid, cn_inv,
+                                             generation=rp_gen))
+
+        # Deleting a key in the new record should NOT result in changes being
+        # recorded...
+        del cn_inv['VCPU']['allocation_ratio']
+        self.assertFalse(pt.has_inventory_changed(cn.uuid, cn_inv))
+        self.assertFalse(pt.update_inventory(cn.uuid, cn_inv,
+                                             generation=rp_gen))
+
+        del cn_inv['MEMORY_MB']
+        self.assertTrue(pt.has_inventory_changed(cn.uuid, cn_inv))
+        self.assertTrue(pt.update_inventory(cn.uuid, cn_inv,
+                                            generation=rp_gen))
+
+        # ...but *adding* a key in the new record *should* result in changes
+        # being recorded
+        cn_inv['VCPU']['reserved'] = 0
+        self.assertTrue(pt.has_inventory_changed(cn.uuid, cn_inv))
+        self.assertTrue(pt.update_inventory(cn.uuid, cn_inv,
+                                            generation=rp_gen))
+
+    def test_have_traits_changed_no_existing_rp(self):
+        pt = self._pt_with_cns()
+        self.assertRaises(
+            ValueError, pt.have_traits_changed, uuids.non_existing_rp, [])
+
+    def test_update_traits_no_existing_rp(self):
+        pt = self._pt_with_cns()
+        self.assertRaises(
+            ValueError, pt.update_traits, uuids.non_existing_rp, [])
+
+    def test_have_traits_changed(self):
+        cn = self.compute_node1
+        pt = self._pt_with_cns()
+        rp_gen = 1
+
+        traits = [
+            "HW_GPU_API_DIRECT3D_V7_0",
+            "HW_NIC_OFFLOAD_SG",
+            "HW_CPU_X86_AVX",
+        ]
+        self.assertTrue(pt.have_traits_changed(cn.uuid, traits))
+        # A data-grab's traits are the same
+        cnsnap = pt.data(cn.uuid)
+        self.assertFalse(pt.have_traits_changed(cn.uuid, cnsnap.traits))
+        self.assertTrue(pt.has_traits(cn.uuid, []))
+        self.assertFalse(pt.has_traits(cn.uuid, traits))
+        self.assertFalse(pt.has_traits(cn.uuid, traits[:1]))
+        self.assertTrue(pt.update_traits(cn.uuid, traits, generation=rp_gen))
+        self.assertTrue(pt.has_traits(cn.uuid, traits))
+        self.assertTrue(pt.has_traits(cn.uuid, traits[:1]))
+
+        # Updating with the same traits info should return False
+        self.assertFalse(pt.have_traits_changed(cn.uuid, traits))
+        # But the generation should get updated
+        rp_gen = 2
+        self.assertFalse(pt.update_traits(cn.uuid, traits, generation=rp_gen))
+        self.assertFalse(pt.have_traits_changed(cn.uuid, traits))
+        self.assertEqual(rp_gen, pt.data(cn.uuid).generation)
+        self.assertTrue(pt.has_traits(cn.uuid, traits))
+        self.assertTrue(pt.has_traits(cn.uuid, traits[:1]))
+
+        # Make a change to the traits list
+        traits.append("HW_GPU_RESOLUTION_W800H600")
+        self.assertTrue(pt.have_traits_changed(cn.uuid, traits))
+        # The previously-taken data now differs
+        self.assertTrue(pt.have_traits_changed(cn.uuid, cnsnap.traits))
+        self.assertFalse(pt.has_traits(cn.uuid, traits[-1:]))
+        # Don't update the generation
+        self.assertTrue(pt.update_traits(cn.uuid, traits))
+        self.assertEqual(rp_gen, pt.data(cn.uuid).generation)
+        self.assertTrue(pt.has_traits(cn.uuid, traits[-1:]))
+
+    def test_add_remove_traits(self):
+        cn = self.compute_node1
+        pt = self._pt_with_cns()
+        self.assertEqual(set([]), pt.data(cn.uuid).traits)
+        # Test adding with no trait provided for a bogus provider
+        pt.add_traits('bogus-uuid')
+        self.assertEqual(
+            set([]),
+            pt.data(cn.uuid).traits
+        )
+        # Add a couple of traits
+        pt.add_traits(cn.uuid, "HW_GPU_API_DIRECT3D_V7_0", "HW_NIC_OFFLOAD_SG")
+        self.assertEqual(
+            set(["HW_GPU_API_DIRECT3D_V7_0", "HW_NIC_OFFLOAD_SG"]),
+            pt.data(cn.uuid).traits)
+        # set() behavior: add a trait that's already there, and one that's not.
+        # The unrelated one is unaffected.
+        pt.add_traits(cn.uuid, "HW_GPU_API_DIRECT3D_V7_0", "HW_CPU_X86_AVX")
+        self.assertEqual(
+            set(["HW_GPU_API_DIRECT3D_V7_0", "HW_NIC_OFFLOAD_SG",
+                 "HW_CPU_X86_AVX"]),
+            pt.data(cn.uuid).traits)
+        # Test removing with no trait provided for a bogus provider
+        pt.remove_traits('bogus-uuid')
+        self.assertEqual(
+            set(["HW_GPU_API_DIRECT3D_V7_0", "HW_NIC_OFFLOAD_SG",
+                 "HW_CPU_X86_AVX"]),
+            pt.data(cn.uuid).traits)
+        # Now remove a trait
+        pt.remove_traits(cn.uuid, "HW_NIC_OFFLOAD_SG")
+        self.assertEqual(
+            set(["HW_GPU_API_DIRECT3D_V7_0", "HW_CPU_X86_AVX"]),
+            pt.data(cn.uuid).traits)
+        # set() behavior: remove a trait that's there, and one that's not.
+        # The unrelated one is unaffected.
+        pt.remove_traits(cn.uuid,
+                         "HW_NIC_OFFLOAD_SG", "HW_GPU_API_DIRECT3D_V7_0")
+        self.assertEqual(set(["HW_CPU_X86_AVX"]), pt.data(cn.uuid).traits)
+        # Remove the last trait, and an unrelated one
+        pt.remove_traits(cn.uuid, "CUSTOM_FOO", "HW_CPU_X86_AVX")
+        self.assertEqual(set([]), pt.data(cn.uuid).traits)
+
+    def test_have_aggregates_changed_no_existing_rp(self):
+        pt = self._pt_with_cns()
+        self.assertRaises(
+            ValueError, pt.have_aggregates_changed, uuids.non_existing_rp, [])
+
+    def test_update_aggregates_no_existing_rp(self):
+        pt = self._pt_with_cns()
+        self.assertRaises(
+            ValueError, pt.update_aggregates, uuids.non_existing_rp, [])
+
+    def test_have_aggregates_changed(self):
+        cn = self.compute_node1
+        pt = self._pt_with_cns()
+        rp_gen = 1
+
+        aggregates = [
+            uuids.agg1,
+            uuids.agg2,
+        ]
+        self.assertTrue(pt.have_aggregates_changed(cn.uuid, aggregates))
+        self.assertTrue(pt.in_aggregates(cn.uuid, []))
+        self.assertFalse(pt.in_aggregates(cn.uuid, aggregates))
+        self.assertFalse(pt.in_aggregates(cn.uuid, aggregates[:1]))
+        self.assertTrue(pt.update_aggregates(cn.uuid, aggregates,
+                                             generation=rp_gen))
+        self.assertTrue(pt.in_aggregates(cn.uuid, aggregates))
+        self.assertTrue(pt.in_aggregates(cn.uuid, aggregates[:1]))
+
+        # data() gets the same aggregates
+        cnsnap = pt.data(cn.uuid)
+        self.assertFalse(
+            pt.have_aggregates_changed(cn.uuid, cnsnap.aggregates))
+
+        # Updating with the same aggregates info should return False
+        self.assertFalse(pt.have_aggregates_changed(cn.uuid, aggregates))
+        # But the generation should get updated
+        rp_gen = 2
+        self.assertFalse(pt.update_aggregates(cn.uuid, aggregates,
+                                              generation=rp_gen))
+        self.assertFalse(pt.have_aggregates_changed(cn.uuid, aggregates))
+        self.assertEqual(rp_gen, pt.data(cn.uuid).generation)
+        self.assertTrue(pt.in_aggregates(cn.uuid, aggregates))
+        self.assertTrue(pt.in_aggregates(cn.uuid, aggregates[:1]))
+
+        # Make a change to the aggregates list
+        aggregates.append(uuids.agg3)
+        self.assertTrue(pt.have_aggregates_changed(cn.uuid, aggregates))
+        self.assertFalse(pt.in_aggregates(cn.uuid, aggregates[-1:]))
+        # Don't update the generation
+        self.assertTrue(pt.update_aggregates(cn.uuid, aggregates))
+        self.assertEqual(rp_gen, pt.data(cn.uuid).generation)
+        self.assertTrue(pt.in_aggregates(cn.uuid, aggregates[-1:]))
+        # Previously-taken data now differs
+        self.assertTrue(pt.have_aggregates_changed(cn.uuid, cnsnap.aggregates))
+
+    def test_add_remove_aggregates(self):
+        cn = self.compute_node1
+        pt = self._pt_with_cns()
+        self.assertEqual(set([]), pt.data(cn.uuid).aggregates)
+        # Add a couple of aggregates
+        pt.add_aggregates(cn.uuid, uuids.agg1, uuids.agg2)
+        self.assertEqual(
+            set([uuids.agg1, uuids.agg2]),
+            pt.data(cn.uuid).aggregates)
+        # set() behavior: add an aggregate that's already there, and one that's
+        # not. The unrelated one is unaffected.
+        pt.add_aggregates(cn.uuid, uuids.agg1, uuids.agg3)
+        self.assertEqual(set([uuids.agg1, uuids.agg2, uuids.agg3]),
+                         pt.data(cn.uuid).aggregates)
+        # Now remove an aggregate
+        pt.remove_aggregates(cn.uuid, uuids.agg2)
+        self.assertEqual(set([uuids.agg1, uuids.agg3]),
+                         pt.data(cn.uuid).aggregates)
+        # set() behavior: remove an aggregate that's there, and one that's not.
+        # The unrelated one is unaffected.
+        pt.remove_aggregates(cn.uuid, uuids.agg2, uuids.agg3)
+        self.assertEqual(set([uuids.agg1]), pt.data(cn.uuid).aggregates)
+        # Remove the last aggregate, and an unrelated one
+        pt.remove_aggregates(cn.uuid, uuids.agg4, uuids.agg1)
+        self.assertEqual(set([]), pt.data(cn.uuid).aggregates)

zun/tests/unit/fake_requests.py

@@ -0,0 +1,39 @@
+#    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.
+"""Fakes relating to the `requests` module."""
+
+import requests
+
+
+class FakeResponse(requests.Response):
+    def __init__(self, status_code, content=None, headers=None):
+        """A requests.Response that can be used as a mock return_value.
+
+        A key feature is that the instance will evaluate to True or False like
+        a real Response, based on the status_code.
+
+        Properties like ok, status_code, text, and content, and methods like
+        json(), work as expected based on the inputs.
+
+        :param status_code: Integer HTTP response code (200, 404, etc.)
+        :param content: String supplying the payload content of the response.
+                        Using a json-encoded string will make the json() method
+                        behave as expected.
+        :param headers: Dict of HTTP header values to set.
+        """
+        super(FakeResponse, self).__init__()
+        self.status_code = status_code
+        if content:
+            self._content = content.encode('utf-8')
+            self.encoding = 'utf-8'
+        if headers:
+            self.headers = headers

zun/tests/unit/objects/test_objects.py

@@ -371,6 +371,7 @@ object_data = {
     'Network': '1.1-26e8d37a54e5fc905ede657744a221d9',
     'ExecInstance': '1.0-59464e7b96db847c0abb1e96d3cec30a',
     'Registry': '1.0-36c2053fbc30e0021630e657dd1699c9',
+    'RequestGroup': '1.0-5e08d68d0a63b729778340d608ec4eae',
 }
 
 

zun/tests/unit/objects/utils.py

@@ -13,6 +13,7 @@
 
 
 from zun import objects
+from zun.objects.numa import NUMATopology
 from zun.tests.unit.db import utils as db_utils
 
 
@@ -62,3 +63,20 @@ def get_test_registry(context, **kwargs):
     for key in db_registry:
         setattr(registry, key, db_registry[key])
     return registry
+
+
+def get_test_compute_node(context, **kwargs):
+    """Return a test compute node object with appropriate attributes.
+
+    NOTE: The object leaves the attributes marked as changed, such
+    that a create() could be used to commit it to the DB.
+    """
+    db_compute_node = db_utils.get_test_compute_node(**kwargs)
+    compute_node = objects.ComputeNode(context)
+    for key in db_compute_node:
+        if key == 'numa_topology':
+            numa_obj = NUMATopology._from_dict(db_compute_node[key])
+            compute_node.numa_topology = numa_obj
+        else:
+            setattr(compute_node, key, db_compute_node[key])
+    return compute_node

zun/tests/unit/scheduler/client/test_query.py

@@ -14,7 +14,7 @@ import mock
 
 from oslo_config import cfg
 
-from zun.scheduler import client as scheduler_client
+from zun.scheduler.client import query as scheduler_client
 from zun.scheduler import filter_scheduler
 from zun.tests import base
 from zun.tests.unit.scheduler import fakes