Detect when internet back to be stable

main.py

import subprocess
import re
import time
import requests
import logging
import os


logging.basicConfig(level=os.getenv('LOG_LEVEL', 'INFO').upper())
logger = logging.getLogger()

MIN_PING_TIME=24 # 13ms
SUCCESS_TIMES=20 # 30 times
WAIT_BETWEEN=1 # 1s
# windows in ms, posix in seconds
PING_TIMEOUT=1000 # 1000ms
HOST='1.1.1.1'
NTFY_URL='https://ntfy.sh/07sQofpjduKx3kyL'


def after_success():
    exit(0)


def on_success():
    logger.info(f'Sending success message to {NTFY_URL}')
    res = requests.post(NTFY_URL, f'Finally we have internet! we got {SUCCESS_TIMES} ping lower than {MIN_PING_TIME}')
    logger.info(f'Sending response is {res.status_code}')
    after_success()
    

def ping(host, timeout_ms, count = 1):
    
    cmd = ['ping']

    # Set timeout
    if timeout_ms:
        if os.name == 'nt':
            cmd.extend(['-w', str(timeout_ms)])
        else:
            # in posix timeout in second
            logger.debug('Posix env detected. using seconds timeout')
            timeout_seconds = int(timeout_ms / 1000)
            cmd.extend(['-w', str(timeout_seconds)])
    # Set count
    if os.name == 'nt':
        cmd.extend(['-n', str(count)])
    else:
        cmd.extend(['-c', str(count)])
    cmd.append(host)
    
    # Spawn
    # logger.debug(f'Spawn {cmd}')
    proc = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
    proc.wait()
    ret = proc.returncode
    # logger.debug(f'Spawn ret: {ret}')
    # Handle failed
    if ret != 0:
        stderr = proc.stderr.read().decode('utf-8')
        logger.debug(f'Spawn ret and stderr: {ret} {stderr}')
        return
    stdout = proc.stdout.read().decode('utf-8')
    # logger.debug(f'STDOUT:\n{stdout}')
    # Parse result
    pattern = re.compile(
        'Reply from ([.|0-9]+): bytes=([0-9]+) time=([0-9]+)ms TTL=([0-9]+)'
        if os.name == 'nt' else
        '([0-9]+) bytes from ([.|0-9]+): icmp_seq=[0-9]+ ttl=([0-9]+) time=([0-9]+).+ ms'
    )
    match = pattern.search(stdout)
    # logger.debug(f'Match is {match}')
    # Handle failed

    if not match or len(match.groups()) != 4:
        logger.error(f'ping of {host} failed! stdout: {stdout}')
        return
    # Get regex result
    if os.name == 'nt':
        host, duration, size, ttl = match.groups()
    else:
        size, host, ttl, duration = match.groups()
    
    logger.debug(f'ping of {host} returned in {duration}ms!')
    return host, float(duration), float(size), float(ttl)

def main():
    success = 0
    while True:
        logger.debug(f'Success {success} times!')
        try:
            result = ping(HOST, PING_TIMEOUT)
        except Exception as e:
            logger.error(e)
            continue
        if result:
            _, duration, _, _ = result
            if duration <= MIN_PING_TIME:
                success += 1
            else:
                success = 0
        else:
            success = 0
        if success >= SUCCESS_TIMES:
            on_success()
        logger.debug(f'SLeeping {WAIT_BETWEEN} seconds')
        time.sleep(WAIT_BETWEEN)

if __name__ == '__main__':
    main()