Integrate FastAPI

The simplest way to combine FastAPI app with Rocketry app is to start both as async tasks. You can modify the Rocketry’s runtime session in FastAPI. There is an existing example project: Rocketry with FastAPI (and React)

First, we create a simple Rocketry app (let’s call this scheduler.py):

# Create Rocketry app
from rocketry import Rocketry
app = Rocketry(execution="async")


# Create some tasks

@app.task('every 5 seconds')
async def do_things():
    ...

if __name__ == "__main__":
    app.run()

Then we create a FastAPI app and manipulate the Rocketry app in it (let’s call this api.py):

# Create FastAPI app
from fastapi import FastAPI
app = FastAPI()

# Import the Rocketry app
from scheduler import app as app_rocketry
session = app_rocketry.session

@app.get("/my-route")
async def get_tasks():
    return session.tasks

@app.post("/my-route")
async def manipulate_session():
    for task in session.tasks:
        ...

if __name__ == "__main__":
    app.run()

Then we combine these in one module (let’s call this main.py):

import asyncio
import uvicorn

from api import app as app_fastapi
from scheduler import app as app_rocketry


class Server(uvicorn.Server):
    """Customized uvicorn.Server

    Uvicorn server overrides signals and we need to include
    Rocketry to the signals."""
    def handle_exit(self, sig: int, frame) -> None:
        app_rocketry.session.shut_down()
        return super().handle_exit(sig, frame)


async def main():
    "Run scheduler and the API"
    server = Server(config=uvicorn.Config(app_fastapi, workers=1, loop="asyncio"))

    api = asyncio.create_task(server.serve())
    sched = asyncio.create_task(app_rocketry.serve())

    await asyncio.wait([sched, api])

if __name__ == "__main__":
    asyncio.run(main())

Note that we need to subclass the uvicorn.Server in order to make sure the scheduler is also closed when the FastAPI app closes. Otherwise the system might not respond on keyboard interrupt.