Coverage for nova/db/api/migrations/env.py: 48%

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

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

3# a copy of the License at 

4# 

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

6# 

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

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

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

10# License for the specific language governing permissions and limitations 

11# under the License. 

12 

13from logging.config import fileConfig 

14 

15from alembic import context 

16from sqlalchemy import engine_from_config 

17from sqlalchemy import pool 

18 

19from nova.db.api import models 

20 

21# this is the Alembic Config object, which provides 

22# access to the values within the .ini file in use. 

23config = context.config 

24 

25# Interpret the config file for Python logging unless we're told not to. 

26# This line sets up loggers basically. 

27if config.attributes.get('configure_logger', True): 27 ↛ 28line 27 didn't jump to line 28 because the condition on line 27 was never true

28 fileConfig(config.config_file_name) 

29 

30# this is the MetaData object for the various models in the API database 

31target_metadata = models.BASE.metadata 

32 

33 

34def include_name(name, type_, parent_names): 

35 """Determine which tables or columns to skip. 

36 

37 This is used when we decide to "delete" a table or column. In this 

38 instance, we will remove the SQLAlchemy model or field but leave the 

39 underlying database table or column in place for a number of releases 

40 after. Once we're sure that there is no code running that contains 

41 references to the old models, we can then remove the underlying table. In 

42 the interim, we must track the discrepancy between models and actual 

43 database data here. 

44 """ 

45 if type_ == 'table': 

46 return name not in models.REMOVED_TABLES 

47 

48 if type_ == 'column': 

49 return (parent_names['table_name'], name) not in models.REMOVED_COLUMNS 

50 

51 return True 

52 

53 

54def run_migrations_offline(): 

55 """Run migrations in 'offline' mode. 

56 

57 This configures the context with just a URL and not an Engine, though an 

58 Engine is acceptable here as well. By skipping the Engine creation we 

59 don't even need a DBAPI to be available. 

60 

61 Calls to context.execute() here emit the given string to the script output. 

62 """ 

63 url = config.get_main_option("sqlalchemy.url") 

64 context.configure( 

65 url=url, 

66 target_metadata=target_metadata, 

67 render_as_batch=True, 

68 include_name=include_name, 

69 literal_binds=True, 

70 dialect_opts={"paramstyle": "named"}, 

71 ) 

72 

73 with context.begin_transaction(): 

74 context.run_migrations() 

75 

76 

77def run_migrations_online(): 

78 """Run migrations in 'online' mode. 

79 

80 In this scenario we need to create an Engine and associate a connection 

81 with the context. 

82 

83 This is modified from the default based on the below, since we want to 

84 share an engine when unit testing so in-memory database testing actually 

85 works. 

86 

87 https://alembic.sqlalchemy.org/en/latest/cookbook.html#connection-sharing 

88 """ 

89 connectable = config.attributes.get('connection', None) 

90 

91 if connectable is None: 91 ↛ 93line 91 didn't jump to line 93 because the condition on line 91 was never true

92 # only create Engine if we don't have a Connection from the outside 

93 connectable = engine_from_config( 

94 config.get_section(config.config_ini_section), 

95 prefix="sqlalchemy.", 

96 poolclass=pool.NullPool, 

97 ) 

98 with connectable.connect() as connection: 

99 context.configure( 

100 connection=connection, 

101 target_metadata=target_metadata, 

102 render_as_batch=True, 

103 include_name=include_name, 

104 ) 

105 

106 with context.begin_transaction(): 

107 context.run_migrations() 

108 else: 

109 context.configure( 

110 connection=connectable, 

111 target_metadata=target_metadata, 

112 render_as_batch=True, 

113 include_name=include_name, 

114 ) 

115 

116 with context.begin_transaction(): 

117 context.run_migrations() 

118 

119 

120if context.is_offline_mode(): 120 ↛ 121line 120 didn't jump to line 121 because the condition on line 120 was never true

121 run_migrations_offline() 

122else: 

123 run_migrations_online()