Move baremetal database tests to fixtures.

The baremetal database tests didn't get migrated to fixtures when we migrated
base nova. Funny story: maybe we should re-use code rather than copying!

So I did that. It's reusable now.

Change-Id: I730aad4a6aedb3993e032a14c9b8d2cd58913b4f

nova/test.py

@@ -37,7 +37,7 @@ import testtools
 from nova import context
 from nova import db
 from nova.db import migration
-from nova.db.sqlalchemy.session import get_engine
+from nova.db.sqlalchemy import session
 from nova.network import manager as network_manager
 from nova.openstack.common import cfg
 from nova.openstack.common import log as logging
@@ -75,38 +75,19 @@ _DB_CACHE = None
 
 class Database(fixtures.Fixture):
 
-    def __init__(self):
-        self.engine = get_engine()
+    def __init__(self, db_session, db_migrate):
+        self.engine = db_session.get_engine()
         self.engine.dispose()
         conn = self.engine.connect()
         if CONF.sql_connection == "sqlite://":
-            if migration.db_version() > migration.INIT_VERSION:
+            if db_migrate.db_version() > db_migrate.INIT_VERSION:
                 return
         else:
             testdb = os.path.join(CONF.state_path, CONF.sqlite_db)
             if os.path.exists(testdb):
                 return
-        migration.db_sync()
-        ctxt = context.get_admin_context()
-        network = network_manager.VlanManager()
-        bridge_interface = CONF.flat_interface or CONF.vlan_interface
-        network.create_networks(ctxt,
-                                label='test',
-                                cidr=CONF.fixed_range,
-                                multi_host=CONF.multi_host,
-                                num_networks=CONF.num_networks,
-                                network_size=CONF.network_size,
-                                cidr_v6=CONF.fixed_range_v6,
-                                gateway=CONF.gateway,
-                                gateway_v6=CONF.gateway_v6,
-                                bridge=CONF.flat_network_bridge,
-                                bridge_interface=bridge_interface,
-                                vpn_start=CONF.vpn_start,
-                                vlan_start=CONF.vlan_start,
-                                dns1=CONF.flat_network_dns)
-        for net in db.network_get_all(ctxt):
-            network.set_network_host(ctxt, net)
-
+        db_migrate.db_sync()
+        self.post_migrations()
         if CONF.sql_connection == "sqlite://":
             conn = self.engine.connect()
             self._DB = "".join(line for line in conn.connection.iterdump())
@@ -128,6 +109,28 @@ class Database(fixtures.Fixture):
                             os.path.join(CONF.state_path,
                                          CONF.sqlite_db))
 
+    def post_migrations(self):
+        """Any addition steps that are needed outside of the migrations."""
+        ctxt = context.get_admin_context()
+        network = network_manager.VlanManager()
+        bridge_interface = CONF.flat_interface or CONF.vlan_interface
+        network.create_networks(ctxt,
+                                label='test',
+                                cidr=CONF.fixed_range,
+                                multi_host=CONF.multi_host,
+                                num_networks=CONF.num_networks,
+                                network_size=CONF.network_size,
+                                cidr_v6=CONF.fixed_range_v6,
+                                gateway=CONF.gateway,
+                                gateway_v6=CONF.gateway_v6,
+                                bridge=CONF.flat_network_bridge,
+                                bridge_interface=bridge_interface,
+                                vpn_start=CONF.vpn_start,
+                                vlan_start=CONF.vlan_start,
+                                dns1=CONF.flat_network_dns)
+        for net in db.network_get_all(ctxt):
+            network.set_network_host(ctxt, net)
+
 
 class ReplaceModule(fixtures.Fixture):
     """Replace a module with a fake module."""
@@ -205,7 +208,7 @@ class TestCase(testtools.TestCase):
 
         global _DB_CACHE
         if not _DB_CACHE:
-            _DB_CACHE = Database()
+            _DB_CACHE = Database(session, migration)
         self.useFixture(_DB_CACHE)
 
         mox_fixture = self.useFixture(MoxStubout())

nova/tests/baremetal/db/base.py

@@ -15,31 +15,25 @@
 
 """Bare-metal DB test base class."""
 
+import fixtures
+
 from nova import context as nova_context
 from nova.openstack.common import cfg
 from nova import test
 from nova.virt.baremetal.db import migration as bm_migration
 from nova.virt.baremetal.db.sqlalchemy import session as bm_session
 
-_DB = None
+_DB_CACHE = None
 
 CONF = cfg.CONF
 CONF.import_opt('baremetal_sql_connection',
                 'nova.virt.baremetal.db.sqlalchemy.session')
 
 
-def _reset_bmdb():
-    global _DB
-    engine = bm_session.get_engine()
-    engine.dispose()
-    conn = engine.connect()
-    if _DB is None:
-        if bm_migration.db_version() > bm_migration.INIT_VERSION:
-            return
-        bm_migration.db_sync()
-        _DB = "".join(line for line in conn.connection.iterdump())
-    else:
-        conn.connection.executescript(_DB)
+class Database(test.Database):
+
+    def post_migrations(self):
+        pass
 
 
 class BMDBTestCase(test.TestCase):
@@ -47,5 +41,8 @@ class BMDBTestCase(test.TestCase):
     def setUp(self):
         super(BMDBTestCase, self).setUp()
         self.flags(baremetal_sql_connection='sqlite:///:memory:')
-        _reset_bmdb()
+        global _DB_CACHE
+        if not _DB_CACHE:
+            _DB_CACHE = Database(bm_session, bm_migration)
+        self.useFixture(_DB_CACHE)
         self.context = nova_context.get_admin_context()