Make sqlite in-memory-db usable to unittest

Move migrate monkey patch from nova.tests.test_migrations to
nova.db.sqlalchemy.migration

Change-Id: I018e44903558cad6311fd368787583322f962d0c

nova/test.py

@@ -40,6 +40,7 @@ from nova.openstack.common import cfg
 from nova import utils
 from nova import service
 from nova.testing.fake import rabbit
+from nova.tests import reset_db
 from nova.virt import fake
 
 
@@ -129,8 +130,7 @@ class TestCase(unittest.TestCase):
         #             now that we have some required db setup for the system
         #             to work properly.
         self.start = utils.utcnow()
-        shutil.copyfile(os.path.join(FLAGS.state_path, FLAGS.sqlite_clean_db),
-                        os.path.join(FLAGS.state_path, FLAGS.sqlite_db))
+        reset_db()
 
         # emulate some of the mox stuff, we can't use the metaclass
         # because it screws with our generators

nova/tests/__init__.py

@@ -34,25 +34,44 @@
 # The code below enables nosetests to work with i18n _() blocks
 import __builtin__
 setattr(__builtin__, '_', lambda x: x)
+import os
+import shutil
+
+from nova.db.sqlalchemy.session import get_engine
+from nova import flags
+
+FLAGS = flags.FLAGS
+
+_DB = None
+
+
+def reset_db():
+    if FLAGS.sql_connection == "sqlite://":
+        engine = get_engine()
+        engine.dispose()
+        conn = engine.connect()
+        conn.connection.executescript(_DB)
+    else:
+        shutil.copyfile(os.path.join(FLAGS.state_path, FLAGS.sqlite_clean_db),
+                        os.path.join(FLAGS.state_path, FLAGS.sqlite_db))
 
 
 def setup():
     import mox  # Fail fast if you don't have mox. Workaround for bug 810424
-    import os
-    import shutil
 
     from nova import context
-    from nova import flags
     from nova import db
     from nova.db import migration
     from nova.network import manager as network_manager
     from nova.tests import fake_flags
 
-    FLAGS = flags.FLAGS
-
-    testdb = os.path.join(FLAGS.state_path, FLAGS.sqlite_db)
-    if os.path.exists(testdb):
-        return
+    if FLAGS.sql_connection == "sqlite://":
+        if migration.db_version() > 1:
+            return
+    else:
+        testdb = os.path.join(FLAGS.state_path, FLAGS.sqlite_db)
+        if os.path.exists(testdb):
+            return
     migration.db_sync()
     ctxt = context.get_admin_context()
     network = network_manager.VlanManager()
@@ -74,5 +93,11 @@ def setup():
     for net in db.network_get_all(ctxt):
         network.set_network_host(ctxt, net)
 
-    cleandb = os.path.join(FLAGS.state_path, FLAGS.sqlite_clean_db)
-    shutil.copyfile(testdb, cleandb)
+    if FLAGS.sql_connection == "sqlite://":
+        global _DB
+        engine = get_engine()
+        conn = engine.connect()
+        _DB = "".join(line for line in conn.connection.iterdump())
+    else:
+        cleandb = os.path.join(FLAGS.state_path, FLAGS.sqlite_clean_db)
+        shutil.copyfile(testdb, cleandb)

nova/tests/fake_flags.py

@@ -37,7 +37,7 @@ FLAGS.set_default('image_service', 'nova.image.fake.FakeImageService')
 flags.DECLARE('iscsi_num_targets', 'nova.volume.driver')
 FLAGS.set_default('iscsi_num_targets', 8)
 FLAGS.set_default('verbose', True)
-FLAGS.set_default('sqlite_db', "tests.sqlite")
+FLAGS.set_default('sql_connection', "sqlite://")
 FLAGS.set_default('use_ipv6', True)
 FLAGS.set_default('flat_network_bridge', 'br100')
 FLAGS.set_default('sqlite_synchronous', False)

nova/tests/test_migrations.py

@@ -26,50 +26,20 @@ if possible.
 
 import ConfigParser
 import commands
-import distutils.version as dist_version
 import os
 import unittest
 import urlparse
 
-import migrate
-from migrate.versioning import util as migrate_util
+from migrate.versioning import repository
 import sqlalchemy
 
 import nova.db.sqlalchemy.migrate_repo
+from nova.db.sqlalchemy.migration import versioning_api as migration_api
 from nova import log as logging
 from nova import test
 
-
 LOG = logging.getLogger('nova.tests.test_migrations')
 
-MIGRATE_PKG_VER = dist_version.StrictVersion(migrate.__version__)
-USE_MIGRATE_PATCH = MIGRATE_PKG_VER < dist_version.StrictVersion('0.7.3')
-
-
-@migrate_util.decorator
-def patched_with_engine(f, *a, **kw):
-    url = a[0]
-    engine = migrate_util.construct_engine(url, **kw)
-
-    try:
-        kw['engine'] = engine
-        return f(*a, **kw)
-    finally:
-        if isinstance(engine, migrate_util.Engine) and engine is not url:
-            migrate_util.log.debug('Disposing SQLAlchemy engine %s', engine)
-            engine.dispose()
-
-
-# TODO(jkoelker) When migrate 0.7.3 is released and nova depends
-#                on that version or higher, this can be removed
-if USE_MIGRATE_PATCH:
-    migrate_util.with_engine = patched_with_engine
-
-
-# NOTE(jkoelker) Delay importing migrate until we are patched
-from migrate.versioning import api as migration_api
-from migrate.versioning import repository
-
 
 class TestMigrations(unittest.TestCase):
     """Test sqlalchemy-migrate migrations"""