ephraimbuddy commented on code in PR #41437: URL: https://github.com/apache/airflow/pull/41437#discussion_r1725134022
########## airflow/utils/db_manager.py: ########## @@ -0,0 +1,176 @@ +# Licensed to the Apache Software Foundation (ASF) under one +# or more contributor license agreements. See the NOTICE file +# distributed with this work for additional information +# regarding copyright ownership. The ASF licenses this file +# to you under the Apache License, Version 2.0 (the +# "License"); you may not use this file except in compliance +# with the License. You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, +# software distributed under the License is distributed on an +# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +# KIND, either express or implied. See the License for the +# specific language governing permissions and limitations +# under the License. +from __future__ import annotations + +import os +from typing import TYPE_CHECKING + +from airflow.configuration import conf +from airflow.exceptions import AirflowException +from airflow.utils.log.logging_mixin import LoggingMixin +from airflow.utils.module_loading import import_string + +if TYPE_CHECKING: + from sqlalchemy import MetaData + + +class AttributeCheckerMeta(type): + """Metaclass to check attributes of subclasses.""" + + def __new__(cls, name, bases, dct): + """Check that subclasses are setting the required attributes.""" + required_attrs = ["metadata", "migration_dir", "alembic_file", "version_table_name"] + for attr in required_attrs: + if attr not in dct: + raise AttributeError(f"{name} is missing required attribute: {attr}") + return super().__new__(cls, name, bases, dct) + + +class BaseDBManager(LoggingMixin, metaclass=AttributeCheckerMeta): + """Base DB manager for external DBs.""" + + metadata: MetaData = None + migration_dir: str = "" + alembic_file: str = "" + version_table_name: str = "" + # Whether the database supports dropping tables when airflow tables are dropped + supports_table_dropping: bool = False + + def __init__(self, session): + super().__init__() + self.session = session + + def get_alembic_config(self): + from alembic.config import Config + + from airflow import settings + + config = Config(self.alembic_file) + config.set_main_option("script_location", self.migration_dir.replace("%", "%%")) + config.set_main_option("sqlalchemy.url", settings.SQL_ALCHEMY_CONN.replace("%", "%%")) + return config + + def get_current_revision(self): + from alembic.migration import MigrationContext + + conn = self.session.connection() + + migration_ctx = MigrationContext.configure(conn, opts={"version_table": self.version_table_name}) + + return migration_ctx.get_current_revision() + + def _create_db_from_orm(self): + """Create database from ORM.""" + from alembic import command + + engine = self.session.get_bind().engine + self.metadata.create_all(engine) + config = self.get_alembic_config() + command.stamp(config, "head") + + def initdb(self): + """Initialize the database.""" + db_exists = self.get_current_revision() + if db_exists: + self.upgradedb() + else: + self._create_db_from_orm() + + def upgradedb(self, to_version=None, from_version=None, show_sql_only=False): + """Upgrade the database.""" + from alembic import command + + config = self.get_alembic_config() + command.upgrade(config, revision=to_version or "heads", sql=show_sql_only) + + def downgradedb(self, to_version, from_version=None, show_sql_only=False): + """Downgrade the database.""" Review Comment: Yes. I think it's better implemented by the subclasses -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
