Add Instances API

Change-Id: Idccee80dce3ed60b491bd3a0fa56429770c618d0

nimble/objects/instance.py

@@ -0,0 +1,79 @@
+# 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 oslo_versionedobjects import base as object_base
+
+from nimble.db import api as dbapi
+from nimble.objects import base
+from nimble.objects import fields as object_fields
+
+
+@base.NimbleObjectRegistry.register
+class Instance(base.NimbleObject, object_base.VersionedObjectDictCompat):
+    # Version 1.0: Initial version
+    VERSION = '1.0'
+
+    dbapi = dbapi.get_instance()
+
+    fields = {
+        'id': object_fields.IntegerField(),
+        'uuid': object_fields.UUIDField(nullable=True),
+        'name': object_fields.StringField(nullable=True),
+        'description': object_fields.StringField(nullable=True),
+        'status': object_fields.StringField(nullable=True),
+        'power_state': object_fields.StringField(nullable=True),
+        'task_state': object_fields.StringField(nullable=True),
+        'instance_type_id': object_fields.IntegerField(nullable=True),
+        'availability_zone': object_fields.StringField(nullable=True),
+        'node_uuid': object_fields.UUIDField(nullable=True),
+        'extra': object_fields.FlexibleDictField(nullable=True),
+    }
+
+    @staticmethod
+    def _from_db_object_list(db_objects, cls, context):
+        """Converts a list of database entities to a list of formal objects."""
+        return [Instance._from_db_object(cls(context), obj)
+                for obj in db_objects]
+
+    @classmethod
+    def list(cls, context):
+        """Return a list of Instance objects."""
+        db_instances = cls.dbapi.instance_get_all()
+        return Instance._from_db_object_list(db_instances, cls, context)
+
+    @classmethod
+    def get(cls, context, instance_id):
+        """Find a instance and return a Instance object."""
+        db_instance = cls.dbapi.instance_get(instance_id)
+        instance = Instance._from_db_object(cls(context), db_instance)
+        return instance
+
+    def create(self, context=None):
+        """Create a Instance record in the DB."""
+        values = self.obj_get_changes()
+        db_instance = self.dbapi.instance_create(values)
+        self._from_db_object(self, db_instance)
+
+    def destroy(self, context=None):
+        """Delete the Instance from the DB."""
+        self.dbapi.instance_destroy(self.uuid)
+        self.obj_reset_changes()
+
+    def save(self, context=None):
+        """Save updates to this Instance."""
+        updates = self.obj_get_changes()
+        self.dbapi.update_instance(self.uuid, updates)
+        self.obj_reset_changes()