Asyncpg reconnection problem demo

demo.py

from asyncio import run, sleep

from asyncpg import InterfaceError
from sqlalchemy.ext.asyncio import create_async_engine


async def main():
    engine = create_async_engine("postgresql+asyncpg://postgres:secret@localhost/testdb")
    while True:
        while True:
            conn = await engine.raw_connection()
            raw_conn = conn.driver_connection
            try:
                await raw_conn.execute("SELECT 1")
                print("Connection established")
            except Exception as exc:
                conn.close()
                print("Error establishing connection:", exc)
                await sleep(1)
            else:
                break

        while True:
            try:
                await raw_conn.execute("SELECT 1")
                print("Connection still works")
                await sleep(1)
            except InterfaceError as exc:
                conn.close()
                print("Error in loop:", exc)
                break
            except BaseException:
                conn.close()
                raise

run(main())

docker-compose.yml

services:
  postgresql:
    image: postgres
    ports:
      - 127.0.0.1:5432:5432
    environment:
      POSTGRES_DB: testdb
      POSTGRES_PASSWORD: secret