Add keypairs to instance_extra

This adds a keypairs deferred-load column to instance_extra where we
can store the keypairs for a given instance instead of referring to
them by name. This is needed for the cell/api split.

Related to blueprint cells-keypairs-api-db

Change-Id: I5a3bf86e2fba21feacf6b59f6a96a0927f044e66

nova/db/sqlalchemy/migrate_repo/versions/332_keypair_in_extra.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 Table
+from sqlalchemy import Text
+
+
+def upgrade(migrate_engine):
+    meta = MetaData()
+    meta.bind = migrate_engine
+
+    for prefix in ('', 'shadow_'):
+        table = Table(prefix + 'instance_extra', meta, autoload=True)
+        new_column = Column('keypairs', Text, nullable=True)
+        if not hasattr(table.c, 'keypairs'):
+            table.create_column(new_column)

nova/db/sqlalchemy/models.py

@@ -376,6 +376,7 @@ class InstanceExtra(BASE, NovaBase, models.SoftDeleteMixin):
     flavor = orm.deferred(Column(Text))
     vcpu_model = orm.deferred(Column(Text))
     migration_context = orm.deferred(Column(Text))
+    keypairs = orm.deferred(Column(Text))
     instance = orm.relationship(Instance,
                             backref=orm.backref('extra',
                                                 uselist=False),

nova/tests/unit/db/test_migrations.py

@@ -895,6 +895,9 @@ class NovaMigrationsCheckers(test_migrations.ModelsMigrationsSync,
         self.assertColumnExists(engine, 'virtual_interfaces', 'tag')
         self.assertColumnExists(engine, 'block_device_mapping', 'tag')
 
+    def _check_332(self, engine, data):
+        self.assertColumnExists(engine, 'instance_extra', 'keypairs')
+
 
 class TestNovaMigrationsSQLite(NovaMigrationsCheckers,
                                test_base.DbTestCase,