Sometimes got error

[redradist]

Describe the bug

Sometimes I see the following issue:

async with repo:
  File "<server>/src/database/repository.py", line 54, in __aenter__
    self._engine = await self._engine_context.__aenter__()
                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/aiopg/utils.py", line 82, in __aenter__
    self._obj = await self._coro
                ^^^^^^^^^^^^^^^^
  File "/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/aiopg/sa/engine.py", line 94, in _create_engine
    pool = await aiopg.create_pool(
           ^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/aiopg/pool.py", line 300, in from_pool_fill
    await self._fill_free_pool(False)
  File "/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/aiopg/pool.py", line 336, in _fill_free_pool
    conn = await connect(
                 ^^^^^^^^
  File "/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/aiopg/connection.py", line 65, in connect
    connection = Connection(
                 ^^^^^^^^^^^
  File "/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/aiopg/connection.py", line 760, in __init__
    self._conn = psycopg2.connect(dsn, **kwargs)
                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/psycopg2/__init__.py", line 122, in connect
    conn = _connect(dsn, connection_factory=connection_factory, **kwasync)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
psycopg2.OperationalError: connection to server at "127.0.0.1", port 5432 failed: Can't assign requested address
        Is the server running on that host and accepting TCP/IP connections?

To Reproduce

1. Use the following class:

class Repository:
    class Settings:
        def __init__(self, database_config):
            self.user = database_config['user'] if 'user' in database_config else None
            self.database = database_config['database'] if 'database' in database_config else None
            self.host = database_config['host'] if 'host' in database_config else None
            self.port = database_config['port'] if 'port' in database_config else None
            self.password = database_config['password'] if 'password' in database_config else None
            self.connection_pool_size = database_config[
                'connection_pool_size'] if 'connection_pool_size' in database_config else None

    def __init__(self, settings: Settings):
        self.settings = settings
        self._engine_context = None
        self._engine: Engine = None

    async def __aenter__(self):
        if self._engine is None:
            if self.settings.connection_pool_size:
                self._engine_context = create_engine(user=self.settings.user,
                                                     database=self.settings.database,
                                                     host=self.settings.host,
                                                     port=self.settings.port,
                                                     password=self.settings.password,
                                                     maxsize=self.settings.connection_pool_size)
            else:
                self._engine_context = create_engine(user=self.settings.user,
                                                     database=self.settings.database,
                                                     host=self.settings.host,
                                                     port=self.settings.port,
                                                     password=self.settings.password)
            self._engine = await self._engine_context.__aenter__()
        return self

    async def __aexit__(self, exc_type, exc_val, exc_tb):
        if self._engine is not None:
            await self._engine_context.__aexit__(exc_type, exc_val, exc_tb)
            self._engine.close()
            self._engine_context.close()
            self._engine = None
            self._engine_context = None
...

2. Try multiples connections from different sources (web page, console and etc.)

Expected behavior

PostgresSQL connections should be established

Logs/tracebacks

async with repo:
  File "<server>/src/database/repository.py", line 54, in __aenter__
    self._engine = await self._engine_context.__aenter__()
                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/aiopg/utils.py", line 82, in __aenter__
    self._obj = await self._coro
                ^^^^^^^^^^^^^^^^
  File "/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/aiopg/sa/engine.py", line 94, in _create_engine
    pool = await aiopg.create_pool(
           ^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/aiopg/pool.py", line 300, in from_pool_fill
    await self._fill_free_pool(False)
  File "/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/aiopg/pool.py", line 336, in _fill_free_pool
    conn = await connect(
                 ^^^^^^^^
  File "/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/aiopg/connection.py", line 65, in connect
    connection = Connection(
                 ^^^^^^^^^^^
  File "/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/aiopg/connection.py", line 760, in __init__
    self._conn = psycopg2.connect(dsn, **kwargs)
                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/psycopg2/__init__.py", line 122, in connect
    conn = _connect(dsn, connection_factory=connection_factory, **kwasync)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
psycopg2.OperationalError: connection to server at "127.0.0.1", port 5432 failed: Can't assign requested address
        Is the server running on that host and accepting TCP/IP connections?

Python Version

$ python --version
Python 3.10.6

aiopg Version

$ python -m pip show aiopg

OS

Linux, MacOS

Additional context

Here is server config used for Repository settings:

database {
  database = <DATABASE_NAME>
  host = "localhost"
  host = ${?DATABASE_HOST}
  port = 5432
  port = ${?DATABASE_PORT}
  user = "postgres"
  user = ${?DATABASE_USER}
  password = "postgres"
  password = ${?DATABASE_PASSWORD}
  connection_pool_size = 50
  url = "postgresql://"${database.user}":"${database.password}"@"${database.host}":"${database.port}"/"${database.database}
}

Code of Conduct

• I agree to follow the aio-libs Code of Conduct