运行依赖于 mysql 容器的 python 容器中的 alembic

Question

我有一个项目，我在其中使用以下 docker-compose.yml 文件：

version: '3'
services:
    python:
        restart: always
        build: ./budget/dockerfiles/python/
        ports:
            - "5000:5000"
        links:
            - db
        depends_on:
            - db
        volumes:
            - ./budget/:/app:z
        entrypoint:
            - python
            - -u
            - /app/run.py

    db:
        build: ./budget/dockerfiles/mysql/
        environment:
            MYSQL_ROOT_PASSWORD: rainmakers
            MYSQL_DATABASE: forecast
            MYSQL_USER: rain
            MYSQL_PASSWORD: rainmakers
        volumes:
            - ./Dump.sql:/db/Dump.sql:z
            - ./Dump_Test.sql:/db/Dump_Test.sql:z
            - ./big_fc.sql:/db/big_fc.sql:z
        ports:
            - "3306:3306"

我还有以下 alembi.ini 文件：

# A generic, single database configuration.

[alembic]
sqlalchemy.url = mysql://username:password@localhost/database_name

# Logging configuration
[loggers]
keys = root,sqlalchemy,alembic

[handlers]
keys = console

[formatters]
keys = generic

[logger_root]
level = WARN
handlers = console
qualname =

[logger_sqlalchemy]
level = WARN
handlers =
qualname = sqlalchemy.engine

[logger_alembic]
level = INFO
handlers =
qualname = alembic

[handler_console]
class = StreamHandler
args = (sys.stderr,)
level = NOTSET
formatter = generic

[formatter_generic]
format = %(levelname)-5.5s [%(name)s] %(message)s
datefmt = %H:%M:%S

我需要运行我的 Python 容器中的命令 alembic upgrade head，但是当我运行它时，我收到以下错误：

Traceback (most recent call last):
  File "/usr/local/bin/alembic", line 11, in <module>
    sys.exit(main())
  File "/usr/local/lib/python2.7/dist-packages/alembic/config.py", line 479, in main
    CommandLine(prog=prog).main(argv=argv)
  File "/usr/local/lib/python2.7/dist-packages/alembic/config.py", line 473, in main
    self.run_cmd(cfg, options)
  File "/usr/local/lib/python2.7/dist-packages/alembic/config.py", line 456, in run_cmd
    **dict((k, getattr(options, k, None)) for k in kwarg)
  File "/usr/local/lib/python2.7/dist-packages/alembic/command.py", line 254, in upgrade
    script.run_env()
  File "/usr/local/lib/python2.7/dist-packages/alembic/script/base.py", line 421, in run_env
    util.load_python_file(self.dir, 'env.py')
  File "/usr/local/lib/python2.7/dist-packages/alembic/util/pyfiles.py", line 93, in load_python_file
    module = load_module_py(module_id, path)
  File "/usr/local/lib/python2.7/dist-packages/alembic/util/compat.py", line 75, in load_module_py
    mod = imp.load_source(module_id, path, fp)
  File "alembic/env.py", line 70, in <module>
    run_migrations_online()
  File "alembic/env.py", line 58, in run_migrations_online
    with connectable.connect() as connection:
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 2085, in connect
    return self._connection_cls(self, **kwargs)
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 90, in __init__
    if connection is not None else engine.raw_connection()
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 2171, in raw_connection
    self.pool.unique_connection, _connection)
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 2145, in _wrap_pool_connect
    e, dialect, self)
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 1456, in _handle_dbapi_exception_noconnection
    exc_info
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/util/compat.py", line 202, in raise_from_cause
    reraise(type(exception), exception, tb=exc_tb, cause=cause)
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 2141, in _wrap_pool_connect
    return fn()
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/pool.py", line 328, in unique_connection
    return _ConnectionFairy._checkout(self)
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/pool.py", line 766, in _checkout
    fairy = _ConnectionRecord.checkout(pool)
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/pool.py", line 516, in checkout
    rec = pool._do_get()
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/pool.py", line 1229, in _do_get
    return self._create_connection()
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/pool.py", line 333, in _create_connection
    return _ConnectionRecord(self)
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/pool.py", line 461, in __init__
    self.__connect(first_connect_check=True)
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/pool.py", line 651, in __connect
    connection = pool._invoke_creator(self)
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/strategies.py", line 105, in connect
    return dialect.connect(*cargs, **cparams)
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/default.py", line 385, in connect
    return self.dbapi.connect(*cargs, **cparams)
  File "/usr/local/lib/python2.7/dist-packages/MySQLdb/__init__.py", line 81, in Connect
    return Connection(*args, **kwargs)
  File "/usr/local/lib/python2.7/dist-packages/MySQLdb/connections.py", line 193, in __init__
    super(Connection, self).__init__(*args, **kwargs2)
sqlalchemy.exc.OperationalError: (_mysql_exceptions.OperationalError) (2002, "Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)")

我猜错误是这个命令试图在我的 python 容器中找到 mysql，但这不在这里，所以我想知道我能做些什么来使它运行正确。

Answer 1

从 python 容器的角度来看，mysql IP 被解析为 mysql 服务的名称：db。解决问题如下：

[alembic]
sqlalchemy.url = mysql://username:password@db/database_name

运行 依赖于 mysql 容器的 python 容器中的 alembic

Running alembic in a python container that depends upon a mysql container

python

mysql

alembic

docker

docker-compose

运行依赖于 mysql 容器的 python 容器中的 alembic