服務器是否在主機“ localhost”（127.0.0.1）上運行並在端口5432上接受TCP / IP連接？

Question

我試圖在Heroku上部署Django項目，但是每次嘗試“ heroku運行python3 manage.py migration”時，都會出現此錯誤：

/app/.heroku/python/lib/python3.6/site-packages/psycopg2/__init__.py:144: UserWarning: The psycopg2 wheel package will be renamed from release 2.8; in order to keep installing from binary please use "pip install psycopg2-binary" instead. For details see: <http://initd.org/psycopg/docs/install.html#binary-install-from-pypi>.
  """)
Traceback (most recent call last):
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/backends/base/base.py", line 216, in ensure_connection
    self.connect()
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/backends/base/base.py", line 194, in connect
    self.connection = self.get_new_connection(conn_params)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/backends/postgresql/base.py", line 168, in get_new_connection
    connection = Database.connect(**conn_params)
  File "/app/.heroku/python/lib/python3.6/site-packages/psycopg2/__init__.py", line 130, in connect
    conn = _connect(dsn, connection_factory=connection_factory, **kwasync)
psycopg2.OperationalError: could not connect to server: Connection refused
    Is the server running on host "localhost" (127.0.0.1) and accepting
    TCP/IP connections on port 5432?


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

Traceback (most recent call last):
  File "manage.py", line 15, in <module>
    execute_from_command_line(sys.argv)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/core/management/__init__.py", line 371, in execute_from_command_line
    utility.execute()
  File "/app/.heroku/python/lib/python3.6/site-packages/django/core/management/__init__.py", line 365, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/core/management/base.py", line 288, in run_from_argv
    self.execute(*args, **cmd_options)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/core/management/base.py", line 335, in execute
    output = self.handle(*args, **options)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/core/management/commands/migrate.py", line 79, in handle
    executor = MigrationExecutor(connection, self.migration_progress_callback)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/migrations/executor.py", line 18, in __init__
    self.loader = MigrationLoader(self.connection)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/migrations/loader.py", line 49, in __init__
    self.build_graph()
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/migrations/loader.py", line 206, in build_graph
    self.applied_migrations = recorder.applied_migrations()
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/migrations/recorder.py", line 61, in applied_migrations
    if self.has_table():
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/migrations/recorder.py", line 44, in has_table
    return self.Migration._meta.db_table in self.connection.introspection.table_names(self.connection.cursor())
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/backends/base/base.py", line 255, in cursor
    return self._cursor()
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/backends/base/base.py", line 232, in _cursor
    self.ensure_connection()
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/backends/base/base.py", line 216, in ensure_connection
    self.connect()
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/utils.py", line 89, in __exit__
    raise dj_exc_value.with_traceback(traceback) from exc_value
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/backends/base/base.py", line 216, in ensure_connection
    self.connect()
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/backends/base/base.py", line 194, in connect
    self.connection = self.get_new_connection(conn_params)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/backends/postgresql/base.py", line 168, in get_new_connection
    connection = Database.connect(**conn_params)
  File "/app/.heroku/python/lib/python3.6/site-packages/psycopg2/__init__.py", line 130, in connect
    conn = _connect(dsn, connection_factory=connection_factory, **kwasync)
django.db.utils.OperationalError: could not connect to server: Connection refused
    Is the server running on host "localhost" (127.0.0.1) and accepting
    TCP/IP connections on port 5432?

我已經研究並嘗試了許多解決方案，但是沒有任何效果。 我在postgres.conf文件中將localhost更改為*，在pg_hba.conf中將127.0.0.1/32更改為0.0.0.0/0，我重新啟動了Postgres並多次運行，並確定其正在運行。 我正在使用Linux和虛擬環境。 還有什么選擇嗎？

Answer 1

好吧，我找到了解決方案。 我需要將此添加到我的settings.py文件中：

from decouple import config
DATABASES = {
    'default': dj_database_url.config(
        default=config('DATABASE_URL')
    )
}