db: Add attachment_id to block_device_mapping

This adds an attachment_id column to the block_device_mapping table as
required for Nova to begin interacting with cinder v3.

Implements: blueprint cinder-new-attach-apis
Change-Id: I5d6afbc22ee89b764440f3313229a29311883f52

nova/block_device.py

@@ -48,7 +48,7 @@ bdm_new_fields = set(['source_type', 'destination_type',
                      'connection_info', 'tag'])
 
 
-bdm_db_only_fields = set(['id', 'instance_uuid'])
+bdm_db_only_fields = set(['id', 'instance_uuid', 'attachment_id'])
 
 
 bdm_db_inherited_fields = set(['created_at', 'updated_at',

nova/db/sqlalchemy/migrate_repo/versions/358_bdm_attachment_id.py

@@ -0,0 +1,28 @@
+#    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 sqlalchemy import Column
+from sqlalchemy import MetaData
+from sqlalchemy import String
+from sqlalchemy import Table
+
+
+def upgrade(migrate_engine):
+    meta = MetaData()
+    meta.bind = migrate_engine
+
+    for prefix in ('', 'shadow_'):
+        table = Table(prefix + 'block_device_mapping', meta, autoload=True)
+        new_column = Column('attachment_id', String(36), nullable=True)
+        if not hasattr(table.c, 'attachment_id'):
+            table.create_column(new_column)

nova/db/sqlalchemy/models.py

@@ -623,6 +623,8 @@ class BlockDeviceMapping(BASE, NovaBase, models.SoftDeleteMixin):
 
     tag = Column(String(255))
 
+    attachment_id = Column(String(36))
+
 
 class SecurityGroupInstanceAssociation(BASE, NovaBase, models.SoftDeleteMixin):
     __tablename__ = 'security_group_instance_association'

nova/tests/unit/db/test_db_api.py

@@ -6360,14 +6360,22 @@ class BlockDeviceMappingTestCase(test.TestCase):
         bdm = self._create_bdm({})
         self.assertIsNotNone(bdm)
 
+    def test_block_device_mapping_create_with_attachment_id(self):
+        bdm = self._create_bdm({'attachment_id': uuidsentinel.attachment_id})
+        self.assertEqual(uuidsentinel.attachment_id, bdm.attachment_id)
+
     def test_block_device_mapping_update(self):
         bdm = self._create_bdm({})
+        self.assertIsNone(bdm.attachment_id)
         result = db.block_device_mapping_update(
-                self.ctxt, bdm['id'], {'destination_type': 'moon'},
-                legacy=False)
+            self.ctxt, bdm['id'],
+            {'destination_type': 'moon',
+             'attachment_id': uuidsentinel.attachment_id},
+            legacy=False)
         uuid = bdm['instance_uuid']
         bdm_real = db.block_device_mapping_get_all_by_instance(self.ctxt, uuid)
         self.assertEqual(bdm_real[0]['destination_type'], 'moon')
+        self.assertEqual(uuidsentinel.attachment_id, bdm_real[0].attachment_id)
         # Also make sure the update call returned correct data
         self.assertEqual(dict(bdm_real[0]),
                          dict(result))

nova/tests/unit/db/test_migrations.py

@@ -943,6 +943,10 @@ class NovaMigrationsCheckers(test_migrations.ModelsMigrationsSync,
                                 'instances_updated_at_project_id_idx',
                                 ['updated_at', 'project_id'])
 
+    def _check_358(self, engine, data):
+        self.assertColumnExists(engine, 'block_device_mapping',
+                                'attachment_id')
+
 
 class TestNovaMigrationsSQLite(NovaMigrationsCheckers,
                                test_base.DbTestCase,