python flask return prior execution of reboot

Question

for reasons I want to trigger the reboot of an raspberry pi using a REST api.

My REST api is coded in python flask like this:

from flask import Flask
from flask import jsonify
import subprocess

app = Flask(__name__)

@app.route('/api/reboot')
def reboot():
    subprocess.call("/sbin/reboot")
    return jsonify(triggered='reboot')

if __name__ == '__main__':
    app.run(debug=True,host="0.0.0.0")

the code is working perfectly fine. But due to its a reboot the return will not be send (because the system is rebooting obviously).

Is there a way to trigger the reboot some kind of async with a delay of a couple milliseconds, that allows to return some value (in my case just an custom 'ack') prior the actual reboot?

Answer 1

Try threading.Timer:

For example:

from flask import Flask
from flask import jsonify
import subprocess
import threading

app = Flask(__name__)

def _reboot():
    subprocess.call("/sbin/reboot")

@app.route('/api/reboot')
def reboot():
    t = threading.Timer(1, _reboot)
    t.start()
    return jsonify(triggered='reboot')

if __name__ == '__main__':
    app.run(debug=True,host="0.0.0.0")