我正在尝试创建一个完整的堆栈应用程序（fastapi后端、postgres数据库和用于迁移的alembic），我使用命令创建了一个postgres docker容器
docker run -p 5432:5432 -e POSTGRES_USER=user -e POSTGRES_PASSWORD=pw --name postgres_db --rm postgres
对于 fastapi 后端，我的 dockerfile 是
FROM python:3.10
WORKDIR /app/
COPY requirements.txt ./
RUN pip install --no-cache-dir -r requirements.txt --upgrade
COPY . .
ENV DATABASE_URL=postgresql://user:pw@postgres_db:5432/user
ENV DB_USER=user
ENV DB_PASSWORD=pw
ENV DB_HOST=postgres_db
ENV DB_PORT=5432
RUN alembic upgrade HEAD
EXPOSE 8000
CMD [ "uvicorn", "main:app", "--reload" ]
当我跑步时
docker build . -t backend
我收到错误为
[+] Building 3.3s (11/11) FINISHED docker:default
=> [internal] load .dockerignore 0.0s
=> => transferring context: 46B 0.0s
=> [internal] load build definition from Dockerfile 0.0s
=> => transferring dockerfile: 410B 0.0s
=> [internal] load metadata for docker.io/library/python:3.10 2.0s
=> [auth] library/python:pull token for registry-1.docker.io 0.0s
=> [internal] load build context 0.0s
=> => transferring context: 1.13kB 0.0s
=> [1/6] FROM docker.io/library/python:3.10@sha256:eac7369136625549bc3f7461fe072b1030f538ea20d6291e9b56896d6a40559c 0.0s
=> CACHED [2/6] WORKDIR /app/ 0.0s
=> CACHED [3/6] COPY requirements.txt ./ 0.0s
=> CACHED [4/6] RUN pip install --no-cache-dir -r requirements.txt --upgrade 0.0s
=> CACHED [5/6] COPY . . 0.0s
=> ERROR [6/6] RUN alembic upgrade HEAD 1.2s
------
> [6/6] RUN alembic upgrade HEAD:
1.100 Traceback (most recent call last):
1.100 File "/usr/local/lib/python3.10/site-packages/sqlalchemy/engine/base.py", line 3371, in _wrap_pool_connect
1.101 return fn()
1.101 File "/usr/local/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 327, in connect
1.101 return _ConnectionFairy._checkout(self)
1.101 File "/usr/local/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 894, in _checkout
1.102 fairy = _ConnectionRecord.checkout(pool)
1.102 File "/usr/local/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 493, in checkout
1.102 rec = pool._do_get()
1.102 File "/usr/local/lib/python3.10/site-packages/sqlalchemy/pool/impl.py", line 256, in _do_get
1.102 return self._create_connection()
1.102 File "/usr/local/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 273, in _create_connection
1.103 return _ConnectionRecord(self)
1.103 File "/usr/local/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 388, in __init__
1.103 self.__connect()
1.103 File "/usr/local/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 690, in __connect
1.103 with util.safe_reraise():
1.103 File "/usr/local/lib/python3.10/site-packages/sqlalchemy/util/langhelpers.py", line 70, in __exit__
1.104 compat.raise_(
1.104 File "/usr/local/lib/python3.10/site-packages/sqlalchemy/util/compat.py", line 211, in raise_
1.104 raise exception
1.104 File "/usr/local/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 686, in __connect
1.104 self.dbapi_connection = connection = pool._invoke_creator(self)
1.104 File "/usr/local/lib/python3.10/site-packages/sqlalchemy/engine/create.py", line 574, in connect
1.105 return dialect.connect(*cargs, **cparams)
1.105 File "/usr/local/lib/python3.10/site-packages/sqlalchemy/engine/default.py", line 598, in connect
1.105 return self.dbapi.connect(*cargs, **cparams)
1.105 File "/usr/local/lib/python3.10/site-packages/psycopg2/__init__.py", line 122, in connect
1.105 conn = _connect(dsn, connection_factory=connection_factory, **kwasync)
1.105 psycopg2.OperationalError: could not translate host name "postgres_db" to address: Name or service not known
1.105
1.105
1.105 The above exception was the direct cause of the following exception:
1.105
1.105 Traceback (most recent call last):
1.105 File "/usr/local/bin/alembic", line 8, in <module>
1.106 sys.exit(main())
1.106 File "/usr/local/lib/python3.10/site-packages/alembic/config.py", line 630, in main
1.106 CommandLine(prog=prog).main(argv=argv)
1.106 File "/usr/local/lib/python3.10/site-packages/alembic/config.py", line 624, in main
1.106 self.run_cmd(cfg, options)
1.106 File "/usr/local/lib/python3.10/site-packages/alembic/config.py", line 601, in run_cmd
1.107 fn(
1.107 File "/usr/local/lib/python3.10/site-packages/alembic/command.py", line 398, in upgrade
1.107 script.run_env()
1.107 File "/usr/local/lib/python3.10/site-packages/alembic/script/base.py", line 579, in run_env
1.108 util.load_python_file(self.dir, "env.py")
1.108 File "/usr/local/lib/python3.10/site-packages/alembic/util/pyfiles.py", line 93, in load_python_file
1.108 module = load_module_py(module_id, path)
1.108 File "/usr/local/lib/python3.10/site-packages/alembic/util/pyfiles.py", line 109, in load_module_py
1.108 spec.loader.exec_module(module) # type: ignore
1.108 File "<frozen importlib._bootstrap_external>", line 883, in exec_module
1.108 File "<frozen importlib._bootstrap>", line 241, in _call_with_frames_removed
1.108 File "/app/alembic/env.py", line 90, in <module>
1.109 run_migrations_online()
1.109 File "/app/alembic/env.py", line 78, in run_migrations_online
1.109 with connectable.connect() as connection:
1.109 File "/usr/local/lib/python3.10/site-packages/sqlalchemy/engine/base.py", line 3325, in connect
1.110 return self._connection_cls(self, close_with_result=close_with_result)
1.110 File "/usr/local/lib/python3.10/site-packages/sqlalchemy/engine/base.py", line 96, in __init__
1.111 else engine.raw_connection()
1.111 File "/usr/local/lib/python3.10/site-packages/sqlalchemy/engine/base.py", line 3404, in raw_connection
1.113 return self._wrap_pool_connect(self.pool.connect, _connection)
1.113 File "/usr/local/lib/python3.10/site-packages/sqlalchemy/engine/base.py", line 3374, in _wrap_pool_connect
1.114 Connection._handle_dbapi_exception_noconnection(
1.114 File "/usr/local/lib/python3.10/site-packages/sqlalchemy/engine/base.py", line 2208, in _handle_dbapi_exception_noconnection
1.115 util.raise_(
1.115 File "/usr/local/lib/python3.10/site-packages/sqlalchemy/util/compat.py", line 211, in raise_
1.115 raise exception
1.115 File "/usr/local/lib/python3.10/site-packages/sqlalchemy/engine/base.py", line 3371, in _wrap_pool_connect
1.117 return fn()
1.117 File "/usr/local/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 327, in connect
1.117 return _ConnectionFairy._checkout(self)
1.117 File "/usr/local/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 894, in _checkout
1.118 fairy = _ConnectionRecord.checkout(pool)
1.118 File "/usr/local/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 493, in checkout
1.118 rec = pool._do_get()
1.118 File "/usr/local/lib/python3.10/site-packages/sqlalchemy/pool/impl.py", line 256, in _do_get
1.118 return self._create_connection()
1.118 File "/usr/local/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 273, in _create_connection
1.119 return _ConnectionRecord(self)
1.119 File "/usr/local/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 388, in __init__
1.119 self.__connect()
1.119 File "/usr/local/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 690, in __connect
1.119 with util.safe_reraise():
1.119 File "/usr/local/lib/python3.10/site-packages/sqlalchemy/util/langhelpers.py", line 70, in __exit__
1.120 compat.raise_(
1.120 File "/usr/local/lib/python3.10/site-packages/sqlalchemy/util/compat.py", line 211, in raise_
1.120 raise exception
1.120 File "/usr/local/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 686, in __connect
1.120 self.dbapi_connection = connection = pool._invoke_creator(self)
1.120 File "/usr/local/lib/python3.10/site-packages/sqlalchemy/engine/create.py", line 574, in connect
1.121 return dialect.connect(*cargs, **cparams)
1.121 File "/usr/local/lib/python3.10/site-packages/sqlalchemy/engine/default.py", line 598, in connect
1.121 return self.dbapi.connect(*cargs, **cparams)
1.121 File "/usr/local/lib/python3.10/site-packages/psycopg2/__init__.py", line 122, in connect
1.121 conn = _connect(dsn, connection_factory=connection_factory, **kwasync)
1.121 sqlalchemy.exc.OperationalError: (psycopg2.OperationalError) could not translate host name "postgres_db" to address: Name or service not known
1.121
1.121 (Background on this error at: https://sqlalche.me/e/14/e3q8)
------
Dockerfile:12
--------------------
10 | ENV DB_PORT=5432
11 | #ENV DB_HOST=172.18.0.2
12 | >>> RUN alembic upgrade HEAD
13 | EXPOSE 8000
14 | CMD [ "uvicorn", "main:app", "--reload" ]
--------------------
ERROR: failed to solve: process "/bin/sh -c alembic upgrade HEAD" did not complete successfully: exit code: 1
当我在本地运行postgres服务时，不会出现错误。我也尝试将我的 postgres_db IP 地址放入环境中，但出现同样的错误。
sqlalchemy.exc.OperationalError: (psycopg2.OperationalError) could not translate host name "postgres_db" to address: Name or service not known
您可以通过使用 127.0.0.1（或 localhost）作为主机地址来解决这个特定问题
ENV DATABASE_URL=postgresql://user:[email protected]:5432/user