Django和Postgres之间的连接错误

Question

我正在用Django设置一个Amazon测试服务器，我在该服务器上使用Postgres作为数据库。这是我来这里的方式

$ sudo apt update
$ sudo apt install python3-pip python3-dev libpq-dev postgresql postgresql-contrib 

我从Github下载了我的文件，并为其创建了一个虚拟环境，并在其中安装了psycopg2。

$ pip install psycopg2

如何配置Postgres：

$ sudo -i -u postgres
$ psql
$ createuser --interactive (super user);
$ createdb Filme;

其他一些可能对Postgres有用的信息：

$ service postgresql status

> postgresql.service - PostgreSQL RDBMS
     Loaded: loaded (/lib/systemd/system/postgresql.service; enabled; vendor preset:>
     Active: active (exited) since Wed 2022-10-05 17:08:25 UTC; 20h ago
   Main PID: 977 (code=exited, status=0/SUCCESS)
        CPU: 1ms

Oct 05 17:08:25 ip-172-31-29-151 systemd[1]: Starting PostgreSQL RDBMS...
Oct 05 17:08:25 ip-172-31-29-151 systemd[1]: Finished PostgreSQL RDBMS.


$ pg_lsclusters

> Ver Cluster Port Status Owner    Data directory              Log file
14  main    5432 online postgres /var/lib/postgresql/14/main /var/log/postgresql/postgresql-14-main.log

在我的项目的settings.py文件中：

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.postgresql_psycopg2',
        'NAME': 'Filme',
        }
}

当我试图运行到新数据库的迁移时，会发生错误：

$ (env) $ python3 manage.py migrate

> Traceback (most recent call last):
  File "/home/ubuntu/Filmes/env/lib/python3.10/site-packages/django/db/backends/base/base.py", line 282, in ensure_connection
    self.connect()
  File "/home/ubuntu/Filmes/env/lib/python3.10/site-packages/django/utils/asyncio.py", line 26, in inner
    return func(*args, **kwargs)
  File "/home/ubuntu/Filmes/env/lib/python3.10/site-packages/django/db/backends/base/base.py", line 263, in connect
    self.connection = self.get_new_connection(conn_params)
  File "/home/ubuntu/Filmes/env/lib/python3.10/site-packages/django/utils/asyncio.py", line 26, in inner
    return func(*args, **kwargs)
  File "/home/ubuntu/Filmes/env/lib/python3.10/site-packages/django/db/backends/postgresql/base.py", line 215, in get_new_connection
    connection = Database.connect(**conn_params)
  File "/home/ubuntu/Filmes/env/lib/python3.10/site-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: FATAL:  role "ubuntu" does not exist


The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/home/ubuntu/Filmes/manage.py", line 22, in <module>
    main()
  File "/home/ubuntu/Filmes/manage.py", line 18, in main
    execute_from_command_line(sys.argv)
  File "/home/ubuntu/Filmes/env/lib/python3.10/site-packages/django/core/management/__init__.py", line 446, in execute_from_command_line
    utility.execute()
  File "/home/ubuntu/Filmes/env/lib/python3.10/site-packages/django/core/management/__init__.py", line 440, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/home/ubuntu/Filmes/env/lib/python3.10/site-packages/django/core/management/base.py", line 402, in run_from_argv
    self.execute(*args, **cmd_options)
  File "/home/ubuntu/Filmes/env/lib/python3.10/site-packages/django/core/management/base.py", line 448, in execute
    output = self.handle(*args, **options)
  File "/home/ubuntu/Filmes/env/lib/python3.10/site-packages/django/core/management/base.py", line 96, in wrapped
    res = handle_func(*args, **kwargs)
  File "/home/ubuntu/Filmes/env/lib/python3.10/site-packages/django/core/management/commands/migrate.py", line 114, in handle
    executor = MigrationExecutor(connection, self.migration_progress_callback)
  File "/home/ubuntu/Filmes/env/lib/python3.10/site-packages/django/db/migrations/executor.py", line 18, in __init__
    self.loader = MigrationLoader(self.connection)
  File "/home/ubuntu/Filmes/env/lib/python3.10/site-packages/django/db/migrations/loader.py", line 58, in __init__
    self.build_graph()
  File "/home/ubuntu/Filmes/env/lib/python3.10/site-packages/django/db/migrations/loader.py", line 235, in build_graph
    self.applied_migrations = recorder.applied_migrations()
  File "/home/ubuntu/Filmes/env/lib/python3.10/site-packages/django/db/migrations/recorder.py", line 81, in applied_migrations
    if self.has_table():
  File "/home/ubuntu/Filmes/env/lib/python3.10/site-packages/django/db/migrations/recorder.py", line 57, in has_table
    with self.connection.cursor() as cursor:
  File "/home/ubuntu/Filmes/env/lib/python3.10/site-packages/django/utils/asyncio.py", line 26, in inner
    return func(*args, **kwargs)
  File "/home/ubuntu/Filmes/env/lib/python3.10/site-packages/django/db/backends/base/base.py", line 323, in cursor
    return self._cursor()
  File "/home/ubuntu/Filmes/env/lib/python3.10/site-packages/django/db/backends/base/base.py", line 299, in _cursor
    self.ensure_connection()
  File "/home/ubuntu/Filmes/env/lib/python3.10/site-packages/django/utils/asyncio.py", line 26, in inner
    return func(*args, **kwargs)
  File "/home/ubuntu/Filmes/env/lib/python3.10/site-packages/django/db/backends/base/base.py", line 281, in ensure_connection
    with self.wrap_database_errors:
  File "/home/ubuntu/Filmes/env/lib/python3.10/site-packages/django/db/utils.py", line 91, in __exit__
    raise dj_exc_value.with_traceback(traceback) from exc_value
  File "/home/ubuntu/Filmes/env/lib/python3.10/site-packages/django/db/backends/base/base.py", line 282, in ensure_connection
    self.connect()
  File "/home/ubuntu/Filmes/env/lib/python3.10/site-packages/django/utils/asyncio.py", line 26, in inner
    return func(*args, **kwargs)
  File "/home/ubuntu/Filmes/env/lib/python3.10/site-packages/django/db/backends/base/base.py", line 263, in connect
    self.connection = self.get_new_connection(conn_params)
  File "/home/ubuntu/Filmes/env/lib/python3.10/site-packages/django/utils/asyncio.py", line 26, in inner
    return func(*args, **kwargs)
  File "/home/ubuntu/Filmes/env/lib/python3.10/site-packages/django/db/backends/postgresql/base.py", line 215, in get_new_connection
    connection = Database.connect(**conn_params)
  File "/home/ubuntu/Filmes/env/lib/python3.10/site-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: FATAL:  role "ubuntu" does not exist

PS:我也遵循了DigitalOcean教程，但最终我陷入了一个几乎相同的错误。(https://www.digitalocean.com/community/tutorials/how-to-set-up-django-with-postgres-nginx-and-gunicorn-on-ubuntu-18-04)

Answer 1

您只配置了ENGINE和NAME设置。您已经将所有其他DB连接设置保留为默认设置，如用户名、密码等。因此，它试图使用当前Linux用户的用户名连接到数据库，该用户名似乎是ubuntu。我猜当您运行createuser时，您没有指定用户名ubuntu，也没有将密码保留为空白，因此需要在Django数据库配置中设置这些设置。

查看您链接的“数字海洋教程”中的所有数据库连接设置，与您在设置文件中配置的两个设置相比。

注意，由于您只是在同一台服务器上运行Django和Postgres，所以您的问题没有任何 AWS。这与在任何其他Linux服务器上配置Django/PostgreSQL的方式相同。如果您正在搜索"django连接到AWS上的postgres“之类的内容(重点关注问题的AWS方面，而实际上您的问题根本没有AWS方面)，这可能会阻止您找到问题的答案。