Adds exact match filters to nova scheduler

Add exact match ram, disk, core filters which will match exact values
of requested metrics, this is required for Baremetal/Ironic instance
filtering.

Unit tests have been proposed to nova at
https://review.openstack.org/#/c/83728

Change-Id: I20faa1c17f4121429bbbea80e59b168095909b48
Closes-Bug: #1291396

ironic/nova/scheduler/filters/exact_core_filter.py

@@ -0,0 +1,50 @@
+# Copyright (c) 2014 OpenStack Foundation
+#
+# 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.
+
+
+from nova.openstack.common.gettextutils import _
+from nova.openstack.common import log as logging
+from nova.scheduler import filters
+
+LOG = logging.getLogger(__name__)
+
+
+class ExactCoreFilter(filters.BaseHostFilter):
+
+    def host_passes(self, host_state, filter_properties):
+        """Return True if host has sufficient CPU cores."""
+        instance_type = filter_properties.get('instance_type')
+        if not instance_type:
+            return True
+
+        if not host_state.vcpus_total:
+            # Fail safe
+            LOG.warning(_("VCPUs not set; assuming CPU collection broken"))
+            return True
+
+        required_vcpus = instance_type['vcpus']
+        usable_vcpus = host_state.vcpus_total - host_state.vcpus_used
+
+        if required_vcpus != usable_vcpus:
+            LOG.debug(_("%(host_state)s does not have %(requested_vcpus)s "
+                        "cores of usable vcpu, it only has %(usable_vcpus)s "
+                        "cores of usable vcpu."),
+                        {'host_state': host_state,
+                        'requested_vcpus': required_vcpus,
+                        'usable_vcpus': usable_vcpus})
+            return False
+
+        return True

ironic/nova/scheduler/filters/exact_disk_filter.py

@@ -0,0 +1,41 @@
+# Copyright (c) 2014 OpenStack Foundation
+# 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.
+
+from nova.openstack.common.gettextutils import _
+from nova.openstack.common import log as logging
+from nova.scheduler import filters
+
+LOG = logging.getLogger(__name__)
+
+
+class ExactDiskFilter(filters.BaseHostFilter):
+    """Exact Disk Filter."""
+
+    def host_passes(self, host_state, filter_properties):
+        """Filter based on disk usage."""
+        instance_type = filter_properties.get('instance_type')
+        requested_disk = (1024 * (instance_type['root_gb'] +
+                                 instance_type['ephemeral_gb']) +
+                         instance_type['swap'])
+
+        if requested_disk != host_state.free_disk_mb:
+            LOG.debug(_("%(host_state)s does not have %(requested_disk)s MB "
+                    "usable disk, it only has %(usable_disk_mb)s MB usable "
+                    "disk."), {'host_state': host_state,
+                               'requested_disk': requested_disk,
+                               'usable_disk_mb': host_state.free_disk_mb})
+            return False
+
+        return True

ironic/nova/scheduler/filters/exact_ram_filter.py

@@ -0,0 +1,37 @@
+# Copyright (c) 2014 OpenStack Foundation
+# 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.
+
+from nova.openstack.common.gettextutils import _
+from nova.openstack.common import log as logging
+from nova.scheduler import filters
+
+LOG = logging.getLogger(__name__)
+
+
+class ExactRamFilter(filters.BaseHostFilter):
+
+    def host_passes(self, host_state, filter_properties):
+        """Only return hosts with sufficient available RAM."""
+        instance_type = filter_properties.get('instance_type')
+        requested_ram = instance_type['memory_mb']
+        if requested_ram != host_state.free_ram_mb:
+            LOG.debug(_("%(host_state)s does not have %(requested_ram)s MB "
+                    "usable ram, it only has %(usable_ram)s MB usable ram."),
+                    {'host_state': host_state,
+                     'requested_ram': requested_ram,
+                     'usable_ram': host_state.free_ram_mb})
+            return False
+
+        return True

ironic/nova/scheduler/ironic_host_manager.py

@@ -20,10 +20,35 @@ This host manager will consume all cpu's, disk space, and
 ram from a host / node as it is supporting Baremetal hosts, which can not be
 subdivided into multiple instances.
 """
+from oslo.config import cfg
 
 from nova.openstack.common import log as logging
 from nova.scheduler import host_manager
 
+host_manager_opts = [
+    cfg.ListOpt('baremetal_scheduler_default_filters',
+                default=[
+                  'RetryFilter',
+                  'AvailabilityZoneFilter',
+                  'ComputeFilter',
+                  'ComputeCapabilitiesFilter',
+                  'ImagePropertiesFilter',
+                  'ExactRamFilter',
+                  'ExactDiskFilter',
+                  'ExactCoreFilter',
+                  ],
+                help='Which filter class names to use for filtering '
+                     'baremetal hosts when not specified in the request.'),
+    cfg.BoolOpt('scheduler_use_baremetal_filters',
+                default=False,
+                help='Flag to decide whether to use '
+                     'baremetal_scheduler_default_filters or not.'),
+
+    ]
+
+CONF = cfg.CONF
+CONF.register_opts(host_manager_opts)
+
 LOG = logging.getLogger(__name__)
 
 
@@ -76,3 +101,6 @@ class IronicHostManager(host_manager.HostManager):
 
     def __init__(self):
         super(IronicHostManager, self).__init__()
+        if CONF.scheduler_use_baremetal_filters:
+            baremetal_default = CONF.baremetal_scheduler_default_filters
+            CONF.scheduler_default_filters = baremetal_default