Is the server running on host “localhost” (127.0.0.1) and accepting TCP/IP connections on port 5432?

问题

I tried to deploy my Django project on Heroku but everytime I try 'heroku run python3 manage.py migrate' I get this error:

/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?

I already researched and tried tons of solutions but nothing works. I changed the localhost to * in postgres.conf file, I changed 127.0.0.1/32 into 0.0.0.0/0 in pg_hba.conf, I restarted Postgres thounsands of times and Im sure its running. I'm using Linux and virtual env. Are there even any options left?

回答1:

Alright, I got the solution. I need to add this into my settings.py file:

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

来源：https://stackoverflow.com/questions/51245505/is-the-server-running-on-host-localhost-127-0-0-1-and-accepting-tcp-ip-conne