I can’t migrate to database from container
I write docker exec -it my_container_app bash
Writing
alembic revision –autogenerate -m “comment”
I get the following error

sqlalchemy.exc.OperationalError: (psycopg2.OperationalError) connection to server at "localhost" (127.0.0.1), port 5432 failed: Connection refused
         Is the server running on that host and accepting TCP/IP connections?
connection to server at "localhost" (::1), port 5432 failed: Cannot assign requested address
         Is the server running on that host and accepting TCP/IP connections?

(Background on this error at: https://sqlalche.me/e/20/e3q8)
And this happens precisely from the container. If I run migrations from Shell, then everything works.

My docker-compose file

version: "3.0"
services:
  db:
    container_name: "db"
    image: postgres:14.1-alpine
    restart: always
    environment:
    - POSTGRES_USER=postgres
    - POSTGRES_PASSWORD=postgres
    - POSTGRES_DB=postgres
    ports:
    - "5432:5432"
    networks:
     - custom
  db_test:
    container_name: "db_test"
    image: postgres:14.1-alpine
    restart: always
    environment:
      - POSTGRES_USER=postgres_test
      - POSTGRES_PASSWORD=postgres_test
      - POSTGRES_DB=postgres_test
    ports:
      - "5433:5432"
    networks:
      - custom
  app:
    container_name: "app"
    image: app:latest
    environment:
      REAL_DATABASE_URL: "postgresql+asyncpg://postgres:postgres@db:5432/postgres"
    build:
      context: .
      dockerfile: Dockerfile
    ports:
      - "8080:80"
    networks:
      - custom
networks:
  custom:
    driver: bridge

My Dockerfile

FROM python:3.9

# Установка telnet
RUN apt-get update && apt-get install -y telnet

WORKDIR /usr/src/app

COPY . .

RUN pip install --no-cache-dir -r requirements.txt

CMD ["uvicorn", "main:app", "--host", "0.0.0.0", "--port", "80"]

EXPOSE 80/tcp

I tried explicitly specifying localhost in the REAL DATABASE_URL like “postgresql+asyncpg://postgres:postgres@localhost:5432/postgres”, but it didn’t help.