主机Django连接Docker容器内PostgreSQL密码验证失败求助

环境配置 #

docker-compose.yml配置 #

postgres:
  image: postgres:13.0-alpine
  volumes:
    - postgres:/var/lib/postgresql/data
  ports:
    - "5432:5432"
  env_file:
    - $ENV_FILE

pgadmin:
  image: dpage/pgadmin4
  volumes:
    - pgadmin:/var/lib/pgadmin
  ports:
    - "${PGADMIN_PORT:-5050}:80"
  restart: unless-stopped
  depends_on:
    - postgres
  env_file:
    - $ENV_FILE

Django数据库配置 #

DATABASES = {
    "default": {
        "ENGINE": os.environ.get("POSTGRES_ENGINE", "django.db.backends.postgresql"),
        "NAME": os.environ.get("POSTGRES_NAME", "postgres"),
        "USER": os.environ.get("POSTGRES_USER", "admin"),
        "PASSWORD": os.environ.get("POSTGRES_PASS", "admin"),
        "HOST": os.environ.get("POSTGRES_HOST", "127.0.0.1"),
        "PORT": os.environ.get("POSTGRES_PORT", "5432"),
    }
}

错误信息 #

Traceback (most recent call last):
  File "C:\Users\liam.obrien\AppData\Local\Programs\Python\Python310\lib\threading.py", line 1009, in _bootstrap_inner
    self.run()
  File "C:\Users\liam.obrien\AppData\Local\Programs\Python\Python310\lib\threading.py", line 946, in run
    self._target(*self._args, **self._kwargs)
  File "C:\Users\liam.obrien\AppData\Local\pypoetry\Cache\virtualenvs\tdd-framework-FOYpVOaj-py3.10\lib\site-packages\django\utils\autoreload.py", line 64, in wrapper
    fn(*args, **kwargs)
  File "C:\Users\liam.obrien\AppData\Local\pypoetry\Cache\virtualenvs\tdd-framework-FOYpVOaj-py3.10\lib\site-packages\channels\management\commands\runserver.py", line 76, in inner_run
    self.check_migrations()
  File "C:\Users\liam.obrien\AppData\Local\pypoetry\Cache\virtualenvs\tdd-framework-FOYpVOaj-py3.10\lib\site-packages\django\core\management\base.py", line 576, in check_migrations
    executor = MigrationExecutor(connections[DEFAULT_DB_ALIAS])
  File "C:\Users\liam.obrien\AppData\Local\pypoetry\Cache\virtualenvs\tdd-framework-FOYpVOaj-py3.10\lib\site-packages\django\db\migrations\executor.py", line 18, in __init__
    self.loader = MigrationLoader(self.connection)
  File "C:\Users\liam.obrien\AppData\Local\pypoetry\Cache\virtualenvs\tdd-framework-FOYpVOaj-py3.10\lib\site-packages\django\db\migrations\loader.py", line 58, in __init__
    self.build_graph()
  File "C:\Users\liam.obrien\AppData\Local\pypoetry\Cache\virtualenvs\tdd-framework-FOYpVOaj-py3.10\lib\site-packages\django\db\migrations\loader.py", line 235, in build_graph
    self.applied_migrations = recorder.applied_migrations()
  File "C:\Users\liam.obrien\AppData\Local\pypoetry\Cache\virtualenvs\tdd-framework-FOYpVOaj-py3.10\lib\site-packages\django\db\migrations\recorder.py", line 81, in applied_migrations
    if self.has_table():
  File "C:\Users\liam.obrien\AppData\Local\pypoetry\Cache\virtualenvs\tdd-framework-FOYpVOaj-py3.10\lib\site-packages\django\db\migrations\recorder.py", line 57, in has_table
    with self.connection.cursor() as cursor:
  File "C:\Users\liam.obrien\AppData\Local\pypoetry\Cache\virtualenvs\tdd-framework-FOYpVOaj-py3.10\lib\site-packages\django\utils\asyncio.py", line 26, in inner
    return func(*args, **kwargs)
  File "C:\Users\liam.obrien\AppData\Local\pypoetry\Cache\virtualenvs\tdd-framework-FOYpVOaj-py3.10\lib\site-packages\django\db\backends\base\base.py", line 284, in cursor
    return self._cursor()
  File "C:\Users\liam.obrien\AppData\Local\pypoetry\Cache\virtualenvs\tdd-framework-FOYpVOaj-py3.10\lib\site-packages\django\db\backends\base\base.py", line 260, in _cursor
    self.ensure_connection()
  File "C:\Users\liam.obrien\AppData\Local\pypoetry\Cache\virtualenvs\tdd-framework-FOYpVOaj-py3.10\lib\site-packages\django\utils\asyncio.py", line 26, in inner
    return func(*args, **kwargs)
  File "C:\Users\liam.obrien\AppData\Local\pypoetry\Cache\virtualenvs\tdd-framework-FOYpVOaj-py3.10\lib\site-packages\django\db\backends\base\base.py", line 243, in ensure_connection
    with self.wrap_database_errors:
  File "C:\Users\liam.obrien\AppData\Local\pypoetry\Cache\virtualenvs\tdd-framework-FOYpVOaj-py3.10\lib\site-packages\django\db\utils.py", line 91, in __exit__
    raise dj_exc_value.with_traceback(traceback) from exc_value
  File "C:\Users\liam.obrien\AppData\Local\pypoetry\Cache\virtualenvs\tdd-framework-FOYpVOaj-py3.10\lib\site-packages\django\db\backends\base\base.py", line 244, in ensure_connection
    self.connect()
  File "C:\Users\liam.obrien\AppData\Local\pypoetry\Cache\virtualenvs\tdd-framework-FOYpVOaj-py3.10\lib\site-packages\django\utils\asyncio.py", line 26, in inner
    return func(*args, **kwargs)
  File "C:\Users\liam.obrien\AppData\Local\pypoetry\Cache\virtualenvs\tdd-framework-FOYpVOaj-py3.10\lib\site-packages\django\db\backends\base\base.py", line 225, in connect
    self.connection = self.get_new_connection(conn_params)
  File "C:\Users\liam.obrien\AppData\Local\pypoetry\Cache\virtualenvs\tdd-framework-FOYpVOaj-py3.10\lib\site-packages\django\utils\asyncio.py", line 26, in inner
    return func(*args, **kwargs)
  File "C:\Users\liam.obrien\AppData\Local\pypoetry\Cache\virtualenvs\tdd-framework-FOYpVOaj-py3.10\lib\site-packages\django\db\backends\postgresql\base.py", line 203, in get_new_connection
    connection = Database.connect(**conn_params)
  File "C:\Users\liam.obrien\AppData\Local\pypoetry\Cache\virtualenvs\tdd-framework-FOYpVOaj-py3.10\lib\site-packages\psycopg2\__init__.py", line 122, in connect
    conn = _connect(dsn, connection_factory=connection_factory, **kwasync)
django.db.utils.OperationalError: connection to server at "127.0.0.1", port 5432 failed: FATAL:  password authentication failed for user "admin"

排查与解决步骤 #

• 统一环境变量键名
  PostgreSQL官方镜像要求的密码环境变量是POSTGRES_PASSWORD，而你的Django配置中用的是POSTGRES_PASS。确保.env文件中同时包含匹配的键值对，或者统一键名：

  • 方式1：修改Django配置，将POSTGRES_PASS改为POSTGRES_PASSWORD，保证和PostgreSQL镜像的环境变量一致：

    "PASSWORD": os.environ.get("POSTGRES_PASSWORD", "admin"),
    

  • 方式2：在.env文件中同时添加POSTGRES_PASSWORD和POSTGRES_PASS，值保持一致。

• 验证本地环境变量是否加载
  在Django配置文件中临时添加打印语句，确认运行Django时是否正确读取到环境变量：

  import os
  print("POSTGRES_USER:", os.environ.get("POSTGRES_USER"))
  print("POSTGRES_PASSWORD:", os.environ.get("POSTGRES_PASSWORD")) # 或POSTGRES_PASS
  

  启动Django服务器，查看控制台输出，如果显示的是默认值admin，说明本地终端未正确加载.env文件，需要手动加载（比如用source .env命令，或者使用dotenv库自动加载）。

• 检查PostgreSQL容器内的用户配置
  进入PostgreSQL容器，验证用户和密码是否正确：

  1. 执行docker exec -it <你的postgres容器ID> bash进入容器
  2. 执行psql -U <POSTGRES_USER> -d <POSTGRES_NAME>，输入.env中的密码，看能否成功登录。如果登录失败，说明容器启动时未正确读取.env变量。

• 清理旧卷数据（若存在配置残留）
  如果之前修改过.env但未清理卷，PostgreSQL会保留旧的用户配置：

  1. 停止容器：docker-compose down
  2. 查看并删除postgres卷：docker volume ls找到对应卷名，执行docker volume rm <卷名>
  3. 重新启动容器：docker-compose up -d

内容的提问来源于stack exchange，提问作者liam