/usr/lib/python3/dist-packages/alembic/templates/multidb/env.py is in python3-alembic 0.9.3-2ubuntu1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 | from __future__ import with_statement
from alembic import context
from sqlalchemy import engine_from_config, pool
from logging.config import fileConfig
import logging
import re
USE_TWOPHASE = False
# this is the Alembic Config object, which provides
# access to the values within the .ini file in use.
config = context.config
# Interpret the config file for Python logging.
# This line sets up loggers basically.
fileConfig(config.config_file_name)
logger = logging.getLogger('alembic.env')
# gather section names referring to different
# databases. These are named "engine1", "engine2"
# in the sample .ini file.
db_names = config.get_main_option('databases')
# add your model's MetaData objects here
# for 'autogenerate' support. These must be set
# up to hold just those tables targeting a
# particular database. table.tometadata() may be
# helpful here in case a "copy" of
# a MetaData is needed.
# from myapp import mymodel
# target_metadata = {
# 'engine1':mymodel.metadata1,
# 'engine2':mymodel.metadata2
#}
target_metadata = {}
# other values from the config, defined by the needs of env.py,
# can be acquired:
# my_important_option = config.get_main_option("my_important_option")
# ... etc.
def run_migrations_offline():
"""Run migrations in 'offline' mode.
This configures the context with just a URL
and not an Engine, though an Engine is acceptable
here as well. By skipping the Engine creation
we don't even need a DBAPI to be available.
Calls to context.execute() here emit the given string to the
script output.
"""
# for the --sql use case, run migrations for each URL into
# individual files.
engines = {}
for name in re.split(r',\s*', db_names):
engines[name] = rec = {}
rec['url'] = context.config.get_section_option(name,
"sqlalchemy.url")
for name, rec in engines.items():
logger.info("Migrating database %s" % name)
file_ = "%s.sql" % name
logger.info("Writing output to %s" % file_)
with open(file_, 'w') as buffer:
context.configure(url=rec['url'], output_buffer=buffer,
target_metadata=target_metadata.get(name),
literal_binds=True)
with context.begin_transaction():
context.run_migrations(engine_name=name)
def run_migrations_online():
"""Run migrations in 'online' mode.
In this scenario we need to create an Engine
and associate a connection with the context.
"""
# for the direct-to-DB use case, start a transaction on all
# engines, then run all migrations, then commit all transactions.
engines = {}
for name in re.split(r',\s*', db_names):
engines[name] = rec = {}
rec['engine'] = engine_from_config(
context.config.get_section(name),
prefix='sqlalchemy.',
poolclass=pool.NullPool)
for name, rec in engines.items():
engine = rec['engine']
rec['connection'] = conn = engine.connect()
if USE_TWOPHASE:
rec['transaction'] = conn.begin_twophase()
else:
rec['transaction'] = conn.begin()
try:
for name, rec in engines.items():
logger.info("Migrating database %s" % name)
context.configure(
connection=rec['connection'],
upgrade_token="%s_upgrades" % name,
downgrade_token="%s_downgrades" % name,
target_metadata=target_metadata.get(name)
)
context.run_migrations(engine_name=name)
if USE_TWOPHASE:
for rec in engines.values():
rec['transaction'].prepare()
for rec in engines.values():
rec['transaction'].commit()
except:
for rec in engines.values():
rec['transaction'].rollback()
raise
finally:
for rec in engines.values():
rec['connection'].close()
if context.is_offline_mode():
run_migrations_offline()
else:
run_migrations_online()
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