fastapi-sqlalchemy-asyncpg/alembic/env.py

import asyncio

from alembic import context
from sqlalchemy.ext.asyncio import create_async_engine

from the_app.models.base import Base as app_base

target_metadata = app_base.metadata


def run_migrations_offline():
    """Run migrations in 'offline' mode.

    This configures the context with just a URL
    and not an Engine, though an Engine is acceptable
    here as well.  By skipping the Engine creation
    we don't even need a DBAPI to be available.

    Calls to context.execute() here emit the given string to the
    script output.

    """
    url = f"postgresql+asyncpg://user:secret@db:5432/devdb"
    context.configure(url=url, target_metadata=target_metadata, literal_binds=True)

    with context.begin_transaction():
        context.run_migrations()


def do_run_migrations(connection):
    context.configure(connection=connection, target_metadata=target_metadata)

    with context.begin_transaction():
        context.run_migrations()


async def run_migrations_online():
    """Run migrations in 'online' mode.

    In this scenario we need to create an Engine
    and associate a connection with the context.

    """
    url = f"postgresql+asyncpg://user:secret@db:5432/devdb"
    connectable = create_async_engine(url)

    async with connectable.connect() as connection:
        await connection.run_sync(do_run_migrations)


if context.is_offline_mode():
    run_migrations_offline()
else:
    asyncio.run(run_migrations_online())