brewman/alembic/env.py

import logging

from sqlalchemy import create_engine
from sqlalchemy import pool

from alembic import context
from brewman.core.config import settings

logging.basicConfig()
logging.getLogger('sqlalchemy.engine').setLevel(settings.ALEMBIC_LOG_LEVEL)
logging.getLogger('alembic').setLevel(settings.ALEMBIC_LOG_LEVEL)

# Interpret the config file for Python logging.
# This line sets up loggers basically.

from brewman.models.auth import User # noqa
target_metadata = User.metadata

# other values from the config, defined by the needs of env.py,
# can be acquired:
# my_important_option = config.get_main_option("my_important_option")
# ... etc.


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 = settings.SQLALCHEMY_DATABASE_URI
    context.configure(
        url=url,
        target_metadata=target_metadata,
        literal_binds=True,
        dialect_opts={"paramstyle": "named"},
        compare_type=True
    )

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


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.

    """
    connectable = create_engine(settings.SQLALCHEMY_DATABASE_URI, poolclass=pool.NullPool, )

    with connectable.connect() as connection:
        context.configure(
            connection=connection, target_metadata=target_metadata,
            compare_type=True
        )

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


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