Merge "add HEAD sentinel file that contains migration revision"

neutron/db/migration/alembic_migrations/versions/HEAD

@@ -0,0 +1 @@
+2447ad0e9585

neutron/db/migration/cli.py

@@ -18,11 +18,14 @@ import os
 
 from alembic import command as alembic_command
 from alembic import config as alembic_config
+from alembic import script as alembic_script
 from alembic import util as alembic_util
 from oslo.config import cfg
 
 from neutron.common import legacy
 
+HEAD_FILENAME = 'HEAD'
+
 
 _core_opts = [
     cfg.StrOpt('core_plugin',
@@ -61,6 +64,7 @@ def do_alembic_command(config, cmd, *args, **kwargs):
 
 def do_check_migration(config, cmd):
     do_alembic_command(config, 'branches')
+    validate_head_file(config)
 
 
 def do_upgrade_downgrade(config, cmd):
@@ -89,6 +93,30 @@ def do_revision(config, cmd):
                        message=CONF.command.message,
                        autogenerate=CONF.command.autogenerate,
                        sql=CONF.command.sql)
+    update_head_file(config)
+
+
+def validate_head_file(config):
+    script = alembic_script.ScriptDirectory.from_config(config)
+    if len(script.get_heads()) > 1:
+        alembic_util.err(_('Timeline branches unable to generate timeline'))
+
+    head_path = os.path.join(script.versions, HEAD_FILENAME)
+    if (os.path.isfile(head_path) and
+        open(head_path).read().strip() == script.get_current_head()):
+        return
+    else:
+        alembic_util.err(_('HEAD file does not match migration timeline head'))
+
+
+def update_head_file(config):
+    script = alembic_script.ScriptDirectory.from_config(config)
+    if len(script.get_heads()) > 1:
+        alembic_util.err(_('Timeline branches unable to generate timeline'))
+
+    head_path = os.path.join(script.versions, HEAD_FILENAME)
+    with open(head_path, 'w+') as f:
+        f.write(script.get_current_head())
 
 
 def add_command_parsers(subparsers):

neutron/tests/unit/test_db_migration.py

@@ -40,6 +40,8 @@ class TestCli(base.BaseTestCase):
         super(TestCli, self).setUp()
         self.do_alembic_cmd_p = mock.patch.object(cli, 'do_alembic_command')
         self.do_alembic_cmd = self.do_alembic_cmd_p.start()
+        self.mock_alembic_err = mock.patch('alembic.util.err').start()
+        self.mock_alembic_err.side_effect = SystemExit
         self.addCleanup(self.do_alembic_cmd_p.stop)
 
     def _main_test_helper(self, argv, func_name, exp_args=(), exp_kwargs={}):
@@ -71,22 +73,28 @@ class TestCli(base.BaseTestCase):
         self._main_test_helper(['prog', 'history'], 'history')
 
     def test_check_migration(self):
-        self._main_test_helper(['prog', 'check_migration'], 'branches')
+        with mock.patch.object(cli, 'validate_head_file') as validate:
+            self._main_test_helper(['prog', 'check_migration'], 'branches')
+            validate.assert_called_once_with(mock.ANY)
 
     def test_database_sync_revision(self):
-        self._main_test_helper(
+        with mock.patch.object(cli, 'update_head_file') as update:
-            ['prog', 'revision', '--autogenerate', '-m', 'message'],
+            self._main_test_helper(
-            'revision',
+                ['prog', 'revision', '--autogenerate', '-m', 'message'],
-            (),
+                'revision',
-            {'message': 'message', 'sql': False, 'autogenerate': True}
+                (),
-        )
+                {'message': 'message', 'sql': False, 'autogenerate': True}
+            )
+            update.assert_called_once_with(mock.ANY)
 
-        self._main_test_helper(
+            update.reset_mock()
-            ['prog', 'revision', '--sql', '-m', 'message'],
+            self._main_test_helper(
-            'revision',
+                ['prog', 'revision', '--sql', '-m', 'message'],
-            (),
+                'revision',
-            {'message': 'message', 'sql': True, 'autogenerate': False}
+                (),
-        )
+                {'message': 'message', 'sql': True, 'autogenerate': False}
+            )
+            update.assert_called_once_with(mock.ANY)
 
     def test_upgrade(self):
         self._main_test_helper(
@@ -117,3 +125,61 @@ class TestCli(base.BaseTestCase):
             ('-2',),
             {'sql': False}
         )
+
+    def _test_validate_head_file_helper(self, heads, file_content=None):
+        with mock.patch('alembic.script.ScriptDirectory.from_config') as fc:
+            fc.return_value.get_heads.return_value = heads
+            fc.return_value.get_current_head.return_value = heads[0]
+            with mock.patch('__builtin__.open') as mock_open:
+                mock_open.return_value.__enter__ = lambda s: s
+                mock_open.return_value.__exit__ = mock.Mock()
+                mock_open.return_value.read.return_value = file_content
+
+                with mock.patch('os.path.isfile') as is_file:
+                    is_file.return_value = file_content is not None
+
+                    if file_content in heads:
+                        cli.validate_head_file(mock.sentinel.config)
+                    else:
+                        self.assertRaises(
+                            SystemExit,
+                            cli.validate_head_file,
+                            mock.sentinel.config
+                        )
+                        self.mock_alembic_err.assert_called_once_with(mock.ANY)
+            fc.assert_called_once_with(mock.sentinel.config)
+
+    def test_validate_head_file_multiple_heads(self):
+        self._test_validate_head_file_helper(['a', 'b'])
+
+    def test_validate_head_file_missing_file(self):
+        self._test_validate_head_file_helper(['a'])
+
+    def test_validate_head_file_wrong_contents(self):
+        self._test_validate_head_file_helper(['a'], 'b')
+
+    def test_validate_head_success(self):
+        self._test_validate_head_file_helper(['a'], 'a')
+
+    def test_update_head_file_multiple_heads(self):
+        with mock.patch('alembic.script.ScriptDirectory.from_config') as fc:
+            fc.return_value.get_heads.return_value = ['a', 'b']
+            self.assertRaises(
+                SystemExit,
+                cli.update_head_file,
+                mock.sentinel.config
+            )
+            self.mock_alembic_err.assert_called_once_with(mock.ANY)
+            fc.assert_called_once_with(mock.sentinel.config)
+
+    def test_update_head_file_success(self):
+        with mock.patch('alembic.script.ScriptDirectory.from_config') as fc:
+            fc.return_value.get_heads.return_value = ['a']
+            fc.return_value.get_current_head.return_value = 'a'
+            with mock.patch('__builtin__.open') as mock_open:
+                mock_open.return_value.__enter__ = lambda s: s
+                mock_open.return_value.__exit__ = mock.Mock()
+
+                cli.update_head_file(mock.sentinel.config)
+                mock_open.write.called_once_with('a')
+            fc.assert_called_once_with(mock.sentinel.config)

tox.ini

@@ -25,6 +25,7 @@ downloadcache = ~/cache/pip
 [testenv:pep8]
 commands =
   flake8
+  neutron-db-manage check_migration
 
 [testenv:i18n]
 commands = python ./tools/check_i18n.py ./neutron ./tools/i18n_cfg.py