Address db_sync check against new install

This patch fixes a bug and causes a log message along with an exit
code to be returned when a DBMigration error is raised.

Change-Id: Iba7aff606937561ad98e2ef551ca4005bd4f337d
Closes-Bug: #1663627

doc/source/upgrading.rst

@@ -225,7 +225,7 @@ authenticate requests normally.
    the previous release.
 
 Using db_sync check
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+~~~~~~~~~~~~~~~~~~~
 
 In order to check the current state of your rolling upgrades, you may run the
 command ``keystone-manage db_sync --check``. This will inform you of any
@@ -239,8 +239,9 @@ can make from your current version. Here are a list of possible return codes.
   database and operator intervention will be required.
 
 * A return code of ``2`` means that an upgrade from your current database
-  version is available and your first step is to run ``keystone-manage
+  version is available, your database is not currently under version control,
-  db_sync --expand``.
+  or the database is already under control. Your first step is to run
+  ``keystone-manage db_sync --expand``.
 
 * A return code of ``3`` means that the expansion stage is complete, and the
   next step is to run ``keystone-manage db_sync --migrate``.

keystone/cmd/cli.py

@@ -21,6 +21,7 @@ import uuid
 
 import migrate
 from oslo_config import cfg
+from oslo_db.sqlalchemy import migration
 from oslo_log import log
 from oslo_log import versionutils
 from oslo_serialization import jsonutils
@@ -457,10 +458,17 @@ class DbSync(BaseApp):
     @classmethod
     def check_db_sync_status(self):
         status = 0
-        expand_version = upgrades.get_db_version(repo='expand_repo')
+        try:
-        migrate_version = upgrades.get_db_version(
+            expand_version = upgrades.get_db_version(repo='expand_repo')
-            repo='data_migration_repo')
+            migrate_version = upgrades.get_db_version(
-        contract_version = upgrades.get_db_version(repo='contract_repo')
+                repo='data_migration_repo')
+            contract_version = upgrades.get_db_version(repo='contract_repo')
+        except migration.exception.DbMigrationError:
+            LOG.info(_LI('Your database is not currently under version '
+                         'control or the database is already controlled. Your '
+                         'first step is to run `keystone-manage db_sync '
+                         '--expand`.'))
+            return 2
 
         repo = migrate.versioning.repository.Repository(
             upgrades.find_repo('expand_repo'))

keystone/tests/unit/test_cli.py

@@ -19,6 +19,7 @@ import uuid
 import fixtures
 import mock
 import oslo_config.fixture
+from oslo_db.sqlalchemy import migration
 from oslo_log import log
 from oslotest import mockpatch
 from six.moves import configparser
@@ -680,6 +681,17 @@ class CliDBSyncTestCase(unit.BaseTestCase):
         cli.DbSync.main()
         self._assert_correct_call(upgrades.contract_schema)
 
+    @mock.patch('keystone.cmd.cli.upgrades.get_db_version')
+    def test_db_sync_check_when_database_is_empty(self, mocked_get_db_version):
+        e = migration.exception.DbMigrationError("Invalid version")
+        mocked_get_db_version.side_effect = e
+        checker = cli.DbSync()
+
+        log_info = self.useFixture(fixtures.FakeLogger(level=log.INFO))
+        status = checker.check_db_sync_status()
+        self.assertIn("not currently under version control", log_info.output)
+        self.assertEqual(status, 2)
+
 
 class TestMappingPopulate(unit.SQLDriverOverrides, unit.TestCase):