Django部署后连接PostgreSQL失败：未提供密码错误排查

错误日志 #

正在使用StatReloader监听文件变更
执行系统检查...
系统检查未发现问题（0项被屏蔽）。
Exception in thread django-main-thread:
Traceback (most recent call last):
  File "/usr/local/lib/python3.10/dist-packages/django/db/backends/base/base.py", line 289, in ensure_connection
    self.connect()
  File "/usr/local/lib/python3.10/dist-packages/django/utils/asyncio.py", line 26, in inner
    return func(*args, **kwargs)
  File "/usr/local/lib/python3.10/dist-packages/django/db/backends/base/base.py", line 270, in connect
    self.connection = self.get_new_connection(conn_params)
  File "/usr/local/lib/python3.10/dist-packages/django/utils/asyncio.py", line 26, in inner
    return func(*args, **kwargs)
  File "/usr/local/lib/python3.10/dist-packages/django/db/backends/postgresql/base.py", line 275, in get_new_connection
    connection = self.Database.connect(**conn_params)
  File "/usr/local/lib/python3.10/dist-packages/psycopg2/__init__.py", line 122, in connect
    conn = _connect(dsn, connection_factory=connection_factory, **kwasync)
psycopg2.OperationalError: connection to server on socket "/var/run/postgresql/.s.PGSQL.5432" failed: fe_sendauth: no password supplied

上述异常直接导致以下异常：

Traceback (most recent call last):
  File "/usr/lib/python3.10/threading.py", line 1016, in _bootstrap_inner
    self.run()
  File "/usr/lib/python3.10/threading.py", line 953, in run
    self._target(*self._args, **self._kwargs)
  File "/usr/local/lib/python3.10/dist-packages/django/utils/autoreload.py", line 64, in wrapper
    fn(*args, **kwargs)
  File "/usr/local/lib/python3.10/dist-packages/django/core/management/commands/runserver.py", line 136, in inner_run
    self.check_migrations()
  File "/usr/local/lib/python3.10/dist-packages/django/core/management/base.py", line 574, in check_migrations
    executor = MigrationExecutor(connections[DEFAULT_DB_ALIAS])
  File "/usr/local/lib/python3.10/dist-packages/django/db/migrations/executor.py", line 18, in __init__
    self.loader = MigrationLoader(self.connection)
  File "/usr/local/lib/python3.10/dist-packages/django/db/migrations/loader.py", line 58, in __init__
    self.build_graph()
  File "/usr/local/lib/python3.10/dist-packages/django/db/migrations/loader.py", line 235, in build_graph
    self.applied_migrations = recorder.applied_migrations()
  File "/usr/local/lib/python3.10/dist-packages/django/db/migrations/recorder.py", line 81, in applied_migrations
    if self.has_table():
  File "/usr/local/lib/python3.10/dist-packages/django/db/migrations/recorder.py", line 57, in has_table
    with self.connection.cursor() as cursor:
  File "/usr/local/lib/python3.10/dist-packages/django/utils/asyncio.py", line 26, in inner
    return func(*args, **kwargs)
  File "/usr/local/lib/python3.10/dist-packages/django/db/backends/base/base.py", line 330, in cursor
    return self._cursor()
  File "/usr/local/lib/python3.10/dist-packages/django/db/backends/base/base.py", line 306, in _cursor
    self.ensure_connection()
  File "/usr/local/lib/python3.10/dist-packages/django/utils/asyncio.py", line 26, in inner
    return func(*args, **kwargs)
  File "/usr/local/lib/python3.10/dist-packages/django/db/backends/base/base.py", line 288, in ensure_connection
    with self.wrap_database_errors:
  File "/usr/local/lib/python3.10/dist-packages/django/db/utils.py", line 91, in __exit__
    raise dj_exc_value.with_traceback(traceback) from exc_value
  File "/usr/local/lib/python3.10/dist-packages/django/db/backends/base/base.py", line 289, in ensure_connection
    self.connect()
  File "/usr/local/lib/python3.10/dist-packages/django/utils/asyncio.py", line 26, in inner
    return func(*args, **kwargs)
  File "/usr/local/lib/python3.10/dist-packages/django/db/backends/base/base.py", line 270, in connect
    self.connection = self.get_new_connection(conn_params)
  File "/usr/local/lib/python3.10/dist-packages/django/utils/asyncio.py", line 26, in inner
    return func(*args, **kwargs)
  File "/usr/local/lib/python3.10/dist-packages/django/db/backends/postgresql/base.py", line 275, in get_new_connection
    connection = self.Database.connect(**conn_params)
  File "/usr/local/lib/python3.10/dist-packages/psycopg2/__init__.py", line 122, in connect
    conn = _connect(dsn, connection_factory=connection_factory, **kwasync)
django.db.utils.OperationalError: connection to server on socket "/var/run/postgresql/.s.PGSQL.5432" failed: fe_sendauth: no password supplied

排查与解决步骤 #

1. 验证Django是否正确读取.env中的密码 #

• 在settings.py中添加打印语句，启动服务器时检查输出：

  import os
  from dotenv import load_dotenv
  
  load_dotenv()
  # 测试用，生产环境需删除
  print("DB_PASSWORD:", os.getenv("DB_PASSWORD"))
  

• 或临时在DATABASES配置中硬编码密码，测试是否能连接：

  DATABASES = {
      'default': {
          # 保留其他配置
          'PASSWORD': '你的实际数据库密码',
      }
  }
  

  若硬编码能连接，说明.env加载或变量引用存在问题。

2. 检查PostgreSQL的pg_hba.conf认证配置 #

• 找到pg_hba.conf文件（通常路径：/etc/postgresql/<版本号>/main/pg_hba.conf）
• 查看本地连接配置行，若为peer认证：

  local   all             all                                     peer
  

  PostgreSQL会使用系统用户身份验证，忽略密码设置，需改为md5或scram-sha-256：

  local   all             all                                     md5
  

• 修改后重启PostgreSQL服务：

  sudo systemctl restart postgresql
  

3. 确认Django数据库配置正确引用环境变量 #

• 检查settings.py中的DATABASES配置，确保密码字段正确引用环境变量：

  DATABASES = {
      'default': {
          'ENGINE': 'django.db.backends.postgresql',
          'NAME': os.getenv('DB_NAME'),
          'USER': os.getenv('DB_USER'),
          'PASSWORD': os.getenv('DB_PASSWORD'),
          'HOST': os.getenv('DB_HOST', 'localhost'),
          'PORT': os.getenv('DB_PORT', '5432'),
      }
  }
  

• 确保在引用环境变量前加载.env文件：

  from dotenv import load_dotenv
  import os
  
  load_dotenv()
  

4. 重启服务清除缓存 #

• 彻底关闭Django开发服务器后重新启动，确保新配置生效
• 若使用Gunicorn、uWSGI等进程管理器，需重启对应进程

内容的提问来源于stack exchange，提问作者coniformx