app.py

import time
import os
import datetime
import requests
from contextlib import asynccontextmanager


from fastapi import FastAPI
from fastapi_utilities import repeat_at

my_data = list( str('-') * 10 )
START_STAT_URL = os.getenv('START_STAT_URL', '')

@asynccontextmanager
async def lifespan(app: FastAPI):
    # --- startup ---
    work()
    # send stat info
    if START_STAT_URL:
        requests.get(f'{START_STAT_URL}?add=HF_der-opt_worker_start_event')
    yield
    # --- shutdown ---

app = FastAPI(lifespan=lifespan)

@repeat_at(cron="*/15 * * * *")
def work():
    now_dtime = datetime.datetime.fromtimestamp(time.time()).strftime('%Y-%m-%d %H:%M:%S')
    my_data.append(now_dtime)
    my_data.pop(0)  # trim old values
    print('-= work! =-')

@app.get("/")
def read_root():
    return {"my_data": my_data}