Enable tasks data model and table for async worker

Add tasks data model and table for async worker to
store the tasks data persistently.

Partially implement blueprint async-glance-workers

Change-Id: I2b2d70295da4905bf75cffc2b2eadec174d1abfc

glance/db/sqlalchemy/migrate_repo/versions/030_add_tasks_table.py

@@ -0,0 +1,66 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+
+# Copyright 2013 OpenStack Foundation
+# All Rights Reserved.
+# Copyright 2013 IBM Corp.
+#
+#    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.schema import (Column, MetaData, Table, Index)
+
+from glance.db.sqlalchemy.migrate_repo.schema import (
+    Boolean, DateTime, String, Text, create_tables, drop_tables)
+
+
+def define_tasks_table(meta):
+    tasks = Table('tasks',
+                  meta,
+                  Column('id', String(36), primary_key=True, nullable=False),
+                  Column('type', String(30), nullable=False),
+                  Column('status', String(30), nullable=False),
+                  Column('owner', String(255), nullable=False),
+                  Column('input', Text()),  # json blob
+                  Column('result', Text()),  # json blob
+                  Column('message', Text()),
+                  Column('expires_at', DateTime(), nullable=True),
+                  Column('created_at', DateTime(), nullable=False),
+                  Column('updated_at', DateTime()),
+                  Column('deleted_at', DateTime()),
+                  Column('deleted',
+                         Boolean(),
+                         nullable=False,
+                         default=False),
+                  mysql_engine='InnoDB',
+                  extend_existing=True)
+
+    Index('ix_tasks_type', tasks.c.type)
+    Index('ix_tasks_status', tasks.c.status)
+    Index('ix_tasks_owner', tasks.c.owner)
+    Index('ix_tasks_deleted', tasks.c.deleted)
+    Index('ix_tasks_updated_at', tasks.c.updated_at)
+
+    return tasks
+
+
+def upgrade(migrate_engine):
+    meta = MetaData()
+    meta.bind = migrate_engine
+    tables = [define_tasks_table(meta)]
+    create_tables(tables)
+
+
+def downgrade(migrate_engine):
+    meta = MetaData()
+    meta.bind = migrate_engine
+    tables = [define_tasks_table(meta)]
+    drop_tables(tables)

glance/db/sqlalchemy/models.py

@@ -214,6 +214,25 @@ class ImageMember(BASE, ModelBase):
     status = Column(String(20), nullable=False, default="pending")
 
 
+class Task(BASE, ModelBase):
+    """Represents an task in the datastore"""
+    __tablename__ = 'tasks'
+    __table_args__ = (Index('ix_tasks_type', 'type'),
+                      Index('ix_tasks_status', 'status'),
+                      Index('ix_tasks_owner', 'owner'),
+                      Index('ix_tasks_deleted', 'deleted'),
+                      Index('ix_tasks_updated_at', 'updated_at'))
+
+    id = Column(String(36), primary_key=True, default=uuidutils.generate_uuid)
+    type = Column(String(30))
+    status = Column(String(30))
+    input = Column(JSONEncodedDict())
+    result = Column(JSONEncodedDict())
+    owner = Column(String(255))
+    message = Column(Text)
+    expires_at = Column(DateTime, nullable=True)
+
+
 def register_models(engine):
     """
     Creates database tables for all models with the given engine

glance/tests/unit/test_migrations.py

@@ -993,3 +993,48 @@ class TestMigrations(utils.BaseTestCase):
             md = r['meta_data']
             d = pickle.loads(md)
             self.assertEqual(type(d), dict)
+
+    def _check_030(self, engine, data):
+        table = "tasks"
+        index_type = ('ix_tasks_type', ['type'])
+        index_status = ('ix_tasks_status', ['status'])
+        index_owner = ('ix_tasks_owner', ['owner'])
+        index_deleted = ('ix_tasks_deleted', ['deleted'])
+        index_updated_at = ('ix_tasks_updated_at', ['updated_at'])
+
+        meta = sqlalchemy.MetaData()
+        meta.bind = engine
+
+        tasks_table = sqlalchemy.Table(table, meta, autoload=True)
+
+        index_data = [(idx.name, idx.columns.keys())
+                      for idx in tasks_table.indexes]
+
+        self.assertIn(index_type, index_data)
+        self.assertIn(index_status, index_data)
+        self.assertIn(index_owner, index_data)
+        self.assertIn(index_deleted, index_data)
+        self.assertIn(index_updated_at, index_data)
+
+        expected = [u'id',
+                    u'type',
+                    u'status',
+                    u'owner',
+                    u'input',
+                    u'result',
+                    u'message',
+                    u'expires_at',
+                    u'created_at',
+                    u'updated_at',
+                    u'deleted_at',
+                    u'deleted']
+
+        # NOTE(flwang): Skip the column type checking for now since Jenkins is
+        # using sqlalchemy.dialects.postgresql.base.TIMESTAMP instead of
+        # DATETIME which is using by mysql and sqlite.
+        col_data = [col.name for col in tasks_table.columns]
+        self.assertEqual(expected, col_data)
+
+    def _post_downgrade_030(self, engine):
+        self.assertRaises(sqlalchemy.exc.NoSuchTableError,
+                          get_table, engine, 'tasks')