from logging.config import fileConfig from sqlalchemy import engine_from_config from sqlalchemy import pool from alembic import context from hydrus.data.db_models import Base import os # this is the Alembic Config object, which provides # access to the values within the .ini file in use. config = context.config # Interpret the config file for Python logging. # This line sets up loggers basically. fileConfig(config.config_file_name) # Setting the DB URL dynamically from "os.environ" if available # or as default sqlite:///database.db # please change it according to your DB Address DB_URL = os.environ['DB_URL'] if 'DB_URL' in dict(os.environ).keys() else 'sqlite:///database.db' config.set_main_option('sqlalchemy.url', DB_URL) # Importing hydrus db_models base for 'autogenerate' support target_metadata = Base.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 = config.get_main_option("sqlalchemy.url") context.configure( url=url, target_metadata=target_metadata, literal_binds=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 = engine_from_config( config.get_section(config.config_ini_section), prefix="sqlalchemy.", poolclass=pool.NullPool, ) with connectable.connect() as connection: context.configure( connection=connection, target_metadata=target_metadata ) with context.begin_transaction(): context.run_migrations() if context.is_offline_mode(): run_migrations_offline() else: run_migrations_online()