Created
July 10, 2024 14:04
-
-
Save demux/e30ece8a87d935c02d956d2855fff218 to your computer and use it in GitHub Desktop.
FastAPI Alembic Migrations
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| from multiprocessing import Process, Queue | |
| from pathlib import Path | |
| from typing import Literal | |
| import alembic.command | |
| from alembic.config import Config | |
| from fastapi import FastAPI | |
| from pydantic import BaseModel | |
| app = FastAPI() | |
| alembic_config_path = (Path(__file__).parent / '../../alembic.ini').resolve() | |
| class RunCommandRequestBody(BaseModel): | |
| cmd: str | |
| class AlembicMigrationRequestBody(BaseModel): | |
| revision: str = 'head' | |
| class AlembicMigrationResponse(BaseModel): | |
| success: bool | |
| AlembicCommand = Literal['upgrade', 'downgrade'] | |
| def alembic_migrate(queue: Queue, cmd: AlembicCommand, revision: str): | |
| # TODO: Make sure errors get reported to Sentry | |
| try: | |
| cfg = Config(alembic_config_path) | |
| getattr(alembic.command, cmd)(cfg, revision) | |
| except Exception as e: | |
| queue.put(False) | |
| raise e | |
| queue.put(True) | |
| def alembic_migrate_process(cmd: AlembicCommand, revision: str) -> bool: | |
| """ | |
| Must run in a subprocess, because otherwise Alembic will mess up FastAPI's logging. | |
| See: https://stackoverflow.com/questions/24622170/using-alembic-api-from-inside-application-code | |
| """ | |
| queue = Queue() | |
| process = Process(target=alembic_migrate, args=(queue, cmd, revision)) | |
| process.start() | |
| process.join(timeout=10 * 60) # 10 min timeout | |
| return queue.get() | |
| @app.post('/alembic/upgrade/', response_model=AlembicMigrationResponse) | |
| async def alembic_upgrade(body: AlembicMigrationRequestBody): | |
| success = alembic_migrate_process('upgrade', body.revision) | |
| return AlembicMigrationResponse(success=success) | |
| @app.post('/alembic/downgrade/', response_model=AlembicMigrationResponse) | |
| async def alembic_downgrade(body: AlembicMigrationRequestBody): | |
| success = alembic_migrate_process('downgrade', body.revision) | |
| return AlembicMigrationResponse(success=success) | |
| if __name__ == '__main__': | |
| import uvicorn | |
| uvicorn.run(app) |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment