Add InstanceTypeFilter as default filters

Change-Id: I480a2e694cfc6b3d22dbe8c7663e63d15fb8e199

nimble/conf/scheduler.py

@@ -34,6 +34,7 @@ opts = [
     cfg.ListOpt('scheduler_default_filters',
                 default=[
                     'AvailabilityZoneFilter',
+                    'InstanceTypeFilter',
                     'CapabilitiesFilter'
                 ],
                 help=_('Which filter class names to use for filtering nodes '

nimble/engine/scheduler/filters/instance_type_filter.py

@@ -0,0 +1,32 @@
+# Copyright 2016 Huawei Technologies Co.,LTD.
+# 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 nimble.engine.scheduler import filters
+
+
+class InstanceTypeFilter(filters.BaseNodeFilter):
+    """Filters Nodes by instance type."""
+
+    # Instance types do not change within a request
+    run_filter_once_per_request = True
+
+    def node_passes(self, node_state, filter_properties):
+        spec = filter_properties.get('request_spec', {})
+        instance_type = spec.get('instance_type', {})
+        type_name = instance_type.get('name')
+
+        if type_name:
+            return type_name == node_state.instance_type
+        return True

setup.cfg

@@ -27,6 +27,7 @@ packages =
 [entry_points]
 nimble.engine.scheduler.filters =
     AvailabilityZoneFilter = nimble.engine.scheduler.filters.availability_zone_filter:AvailabilityZoneFilter
+    InstanceTypeFilter = nimble.engine.scheduler.filters.instance_type_filter:InstanceTypeFilter
     CapabilitiesFilter = nimble.engine.scheduler.filters.capabilities_filter:CapabilitiesFilter
     JsonFilter = nimble.engine.scheduler.filters.json_filter:JsonFilter