keepalive.py

from fastapi import FastAPI
from fastapi.responses import HTMLResponse
import os

keepalive = FastAPI()

@keepalive.get("/", response_class=HTMLResponse)
def root():
    return open("index.html").read()

@keepalive.head("/")
def root_head():
    return "OK"

os.system("python app.py 1>/dev/null 2>/dev/null &")