Test fixture for the api database

In order to run fuctional tests against the database we should have a
fixture to handle the setup and cleanup.  This adapts the current
Database fixture to work for either database.  It is left out the Nova
TestCase test class and should be set up in specific test classes that
need it.

Change-Id: I98e98cb6dea0008d36397b4e2bf7fcf9ed721721

nova/tests/fixtures.py

@@ -35,7 +35,7 @@ from nova.tests.functional.api import client
 _TRUE_VALUES = ('True', 'true', '1', 'yes')
 
 CONF = cfg.CONF
-DB_SCHEMA = ""
+DB_SCHEMA = {'main': "", 'api': ""}
 
 
 class ServiceFixture(fixtures.Fixture):
@@ -190,25 +190,34 @@ class Timeout(fixtures.Fixture):
 
 
 class Database(fixtures.Fixture):
+    def __init__(self, database='main'):
+        super(Database, self).__init__()
+        self.database = database
+        if database == 'main':
+            self.get_engine = session.get_engine
+        elif database == 'api':
+            self.get_engine = session.get_api_engine
+
     def _cache_schema(self):
         global DB_SCHEMA
-        if not DB_SCHEMA:
-            engine = session.get_engine()
+        if not DB_SCHEMA[self.database]:
+            engine = self.get_engine()
             conn = engine.connect()
-            migration.db_sync()
-            DB_SCHEMA = "".join(line for line in conn.connection.iterdump())
+            migration.db_sync(database=self.database)
+            DB_SCHEMA[self.database] = "".join(line for line
+                                               in conn.connection.iterdump())
             engine.dispose()
 
     def cleanup(self):
-        engine = session.get_engine()
+        engine = self.get_engine()
         engine.dispose()
 
     def reset(self):
         self._cache_schema()
-        engine = session.get_engine()
+        engine = self.get_engine()
         engine.dispose()
         conn = engine.connect()
-        conn.connection.executescript(DB_SCHEMA)
+        conn.connection.executescript(DB_SCHEMA[self.database])
 
     def setUp(self):
         super(Database, self).setUp()

nova/tests/unit/conf_fixture.py

@@ -58,7 +58,10 @@ class ConfFixture(config_fixture.Config):
         self.conf.set_default('auth_strategy', 'noauth2')
         config.parse_args([], default_config_files=[])
         self.conf.set_default('connection', "sqlite://", group='database')
+        self.conf.set_default('connection', "sqlite://", group='api_database')
         self.conf.set_default('sqlite_synchronous', False, group='database')
+        self.conf.set_default('sqlite_synchronous', False,
+                group='api_database')
         self.conf.set_default('fatal_exception_format_errors', True)
         self.conf.set_default('enabled', True, 'osapi_v3')
         self.conf.set_default('force_dhcp_release', False)

nova/tests/unit/test_fixtures.py

@@ -19,6 +19,7 @@ import sys
 import fixtures as fx
 from oslo_config import cfg
 from oslo_log import log as logging
+from oslo_utils import uuidutils
 import testtools
 
 from nova.db.sqlalchemy import api as session
@@ -206,6 +207,34 @@ class TestDatabaseFixture(testtools.TestCase):
         rows = result.fetchall()
         self.assertEqual(len(rows), 5, "Rows %s" % rows)
 
+    def test_api_fixture_reset(self):
+        # This sets up reasonable db connection strings
+        self.useFixture(conf_fixture.ConfFixture())
+        self.useFixture(fixtures.Database(database='api'))
+        engine = session.get_api_engine()
+        conn = engine.connect()
+        result = conn.execute("select * from cell_mappings")
+        rows = result.fetchall()
+        self.assertEqual(len(rows), 0, "Rows %s" % rows)
+
+        uuid = uuidutils.generate_uuid()
+        conn.execute("insert into cell_mappings (uuid, name) VALUES "
+                     "('%s', 'fake-cell')" % (uuid,))
+        result = conn.execute("select * from cell_mappings")
+        rows = result.fetchall()
+        self.assertEqual(len(rows), 1, "Rows %s" % rows)
+
+        # reset by invoking the fixture again
+        #
+        # NOTE(sdague): it's important to reestablish the db
+        # connection because otherwise we have a reference to the old
+        # in mem db.
+        self.useFixture(fixtures.Database(database='api'))
+        conn = engine.connect()
+        result = conn.execute("select * from cell_mappings")
+        rows = result.fetchall()
+        self.assertEqual(len(rows), 0, "Rows %s" % rows)
+
     def test_fixture_cleanup(self):
         # because this sets up reasonable db connection strings
         self.useFixture(conf_fixture.ConfFixture())
@@ -220,3 +249,28 @@ class TestDatabaseFixture(testtools.TestCase):
         conn = engine.connect()
         schema = "".join(line for line in conn.connection.iterdump())
         self.assertEqual(schema, "BEGIN TRANSACTION;COMMIT;")
+
+    def test_api_fixture_cleanup(self):
+        # This sets up reasonable db connection strings
+        self.useFixture(conf_fixture.ConfFixture())
+        fix = fixtures.Database(database='api')
+        self.useFixture(fix)
+
+        # No data inserted by migrations so we need to add a row
+        engine = session.get_api_engine()
+        conn = engine.connect()
+        uuid = uuidutils.generate_uuid()
+        conn.execute("insert into cell_mappings (uuid, name) VALUES "
+                     "('%s', 'fake-cell')" % (uuid,))
+        result = conn.execute("select * from cell_mappings")
+        rows = result.fetchall()
+        self.assertEqual(len(rows), 1, "Rows %s" % rows)
+
+        # Manually do the cleanup that addCleanup will do
+        fix.cleanup()
+
+        # Ensure the db contains nothing
+        engine = session.get_api_engine()
+        conn = engine.connect()
+        schema = "".join(line for line in conn.connection.iterdump())
+        self.assertEqual(schema, "BEGIN TRANSACTION;COMMIT;")