Flash LED depending on 'net connection. Reboot after 1 hour disconnected. PiZero only.

heartbeat.py

#!/usr/bin/env python3

#
# PiZero : flash LED depending on 'net connection. Reboot after 1 hour disconnected.
#

from subprocess import run
from time import sleep
import socket
from datetime import datetime as dt
import os


period = 60 # check every : 1 min
reboot_after = 60*60 # reboot if disconnected for: 1 hr

def led_on():
    with  open("/sys/class/leds/led0//brightness", "w") as f:
        print("1", file=f)


def led_off():
    with  open("/sys/class/leds/led0//brightness", "w") as f:
        print("0", file=f)


def is_connected():
    try:
        # connect to the host -- tells us if the host is actually reachable
        socket.create_connection(("1.1.1.1", 53))
        return True
    except OSError:
        pass
    return False

disconnected_period = 0

try:
    while True:
        if is_connected():
            disconnected_period = 0
            for t in range(10 * period):
                # .1s total
                led_on()
                sleep(.09)
                led_off()
                sleep(.01)
        else:
            for t in range(1 * period):
                # 1s total
                led_on()
                sleep(.1)
                led_off()
                sleep(.9)
            disconnected_period += period
            print(f"{disconnected_period} {period}")
            if disconnected_period > reboot_after:
                print(f"No internet. Rebooting at {dt.now()}")
                os.system('reboot')
finally:
    led_on()