Coverage for watcher/db/sqlalchemy/migration.py: 73%

1# Copyright 2010 United States Government as represented by the 

2# Administrator of the National Aeronautics and Space Administration. 

3# All Rights Reserved. 

4# 

5# Licensed under the Apache License, Version 2.0 (the "License"); you may 

6# not use this file except in compliance with the License. You may obtain 

7# a copy of the License at 

8# 

9# http://www.apache.org/licenses/LICENSE-2.0 

10# 

11# Unless required by applicable law or agreed to in writing, software 

12# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 

13# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the 

14# License for the specific language governing permissions and limitations 

15# under the License. 

16 

17import os 

18 

19import alembic 

20from alembic import config as alembic_config 

21import alembic.migration as alembic_migration 

22from oslo_db import exception as db_exc 

23from oslo_db.sqlalchemy import enginefacade 

24 

25from watcher._i18n import _ 

26from watcher.db.sqlalchemy import models 

27 

28 

29def _alembic_config(): 

30 path = os.path.join(os.path.dirname(__file__), 'alembic.ini') 

31 config = alembic_config.Config(path) 

32 return config 

33 

34 

35def version(engine=None): 

36 """Current database version. 

37 

38 :returns: Database version 

39 :rtype: string 

40 """ 

41 if engine is None: 

42 engine = enginefacade.reader.get_engine() 

43 with engine.connect() as conn: 

44 context = alembic_migration.MigrationContext.configure(conn) 

45 return context.get_current_revision() 

46 

47 

48def upgrade(revision, config=None): 

49 """Used for upgrading database. 

50 

51 :param version: Desired database version 

52 :type version: string 

53 """ 

54 revision = revision or 'head' 

55 config = config or _alembic_config() 

56 

57 alembic.command.upgrade(config, revision) 

58 

59 

60def create_schema(config=None, engine=None): 

61 """Create database schema from models description. 

62 

63 Can be used for initial installation instead of upgrade('head'). 

64 """ 

65 if engine is None: 65 ↛ 71line 65 didn't jump to line 71 because the condition on line 65 was always true

66 engine = enginefacade.writer.get_engine() 

67 

68 # NOTE(viktors): If we will use metadata.create_all() for non empty db 

69 # schema, it will only add the new tables, but leave 

70 # existing as is. So we should avoid of this situation. 

71 if version(engine=engine) is not None: 71 ↛ anywhereline 71 didn't jump anywhere: it always raised an exception.

72 raise db_exc.DBMigrationError( 

73 _("Watcher database schema is already under version control; " 

74 "use upgrade() instead")) 

75 

76 models.Base.metadata.create_all(engine) 

77 stamp('head', config=config) 

78 

79 

80def downgrade(revision, config=None): 

81 """Used for downgrading database. 

82 

83 :param version: Desired database version 

84 :type version: string 

85 """ 

86 revision = revision or 'base' 

87 config = config or _alembic_config() 

88 return alembic.command.downgrade(config, revision) 

89 

90 

91def stamp(revision, config=None): 

92 """Stamps database with provided revision. 

93 

94 Don't run any migrations. 

95 

96 :param revision: Should match one from repository or head - to stamp 

97 database with most recent revision 

98 :type revision: string 

99 """ 

100 config = config or _alembic_config() 

101 return alembic.command.stamp(config, revision=revision) 

102 

103 

104def revision(message=None, autogenerate=False, config=None): 

105 """Creates template for migration. 

106 

107 :param message: Text that will be used for migration title 

108 :type message: string 

109 :param autogenerate: If True - generates diff based on current database 

110 state 

111 :type autogenerate: bool 

112 """ 

113 config = config or _alembic_config() 

114 return alembic.command.revision(config, message=message, 

115 autogenerate=autogenerate)