Creates a log, useful for dodgy internet. Checks every minute and creates an empty lock file to stop being run more than once. Add to cron or set as a service to make it start automatically

uptime.py

import time
import sys
import datetime
from os.path import isfile as file_exists
from os import remove as file_delete
import os
from ping3 import ping
import signal
import sys

# User configurable settings
LOG_FILENAME = "uptime_log.txt"
LOCK_FILENAME = "uptime.lock"
DATETIME_FORMAT = "%Y-%m-%d %H:%M:%S"
RECORD_INTERVAL_SECS_DETECT = 30
RECORD_INTERVAL_SECS_FAILURE = 5

def write_log(text):
    log = open(LOG_FILENAME, "a", os.O_NONBLOCK)
    dt = datetime.datetime.now()
    log.write(dt.strftime(DATETIME_FORMAT) + ': ' + text + '\n')
    log.close()

if file_exists(LOCK_FILENAME):
    write_log("cron - checking uptime script is running.")
    sys.exit(0)

last = -1
lock = open(LOCK_FILENAME, "x")

def sig_handler(sig, frame):
    write_log("stopping internet uptime check")
    time.sleep(1)
    lock.close()
    file_delete(LOCK_FILENAME)
    print('Stopped')
    sys.exit(0)

signal.signal(signal.SIGINT, sig_handler)
signal.signal(signal.SIGTERM, sig_handler)

while True:
    internet = ping("8.8.8.8") is not None

    if last == -1:
        write_log("start of internet uptime check")
    if not last == internet:
        write_log('internet is ' + ('up' if internet else 'down'))
    last = internet

    time.sleep((RECORD_INTERVAL_SECS_DETECT if internet else RECORD_INTERVAL_SECS_FAILURE))