Finds IPs for DNS name if randomly changes - most credit to @nyuszika7h

DNSfind.py

#!/usr/bin/env python3

import argparse
import logging
import random
import socket
import sys
import _thread
import threading
import time
import os

import requests


def handle_timeout():
    logger.info(f'No new IPs found in {args.timeout} seconds, exiting')
    _thread.interrupt_main()


parser = argparse.ArgumentParser(prog='gettgips')
parser.add_argument(
    'filename',
    help='file to write IPs to',
)
parser.add_argument(
    'hostnames',
    help='comma-separated list of hostnames to look up',
)
parser.add_argument(
    '-d',
    '--delay',
    type=float,
    default=0.2,
    help='seconds between lookups',
)
parser.add_argument(
    '-s',
    '--host-suffix',
    default='.torguardvpnaccess.com',
    help='suffix to append after the listed hostnames',
)

parser.add_argument(
    '-gi',
    '--getIPinfo',
    action = 'store_true',
    help='suffix to append after the listed hostnames',
)

parser.add_argument(
    '-t',
    '--timeout',
    type=int,
    default=300,
    help='exit if no new IPs found after this many seconds',
)
parser.add_argument(
    '--debug',
    action='store_true',
    help='enable debug logging',
)
args = parser.parse_args()

logging.basicConfig(
    level=logging.DEBUG if args.debug else logging.INFO,
    format='[%(asctime)s.%(msecs)03d] %(levelname)s - %(message)s',
    datefmt='%Y-%m-%d %H:%M:%S',
)
logger = logging.getLogger()


try:
    fd = open(args.filename, 'a+')
    fd.seek(0)
    ips = [x for x in fd.read().split('\n') if x]

    logger.info(
        f'Loaded {len(ips)} known IP{"" if len(ips) == 1 else "s"} from {args.filename}',
    )

    if args.timeout > 0:
        logger.debug(f'Starting timer ({args.timeout}s)')
        timer = threading.Timer(args.timeout, handle_timeout)
        timer.start()

    hostnames = args.hostnames.split(',')

    n = len(hostnames)
    logger.info(f'Testing {n} hostname{"" if n == 1 else "s"}')

    while True:
        host = random.choice(hostnames)

        host += args.host_suffix
        #~ print(host)
        ip = socket.gethostbyname(host)
        logger.debug(f'gethostbyname({host}) => {ip}')

        if ip not in ips:
            ips.append(ip)
            fd.write(f'{ip}\n')
            fd.flush()
            logger.info(f'Found new IP #{len(ips)}: {ip} ({host})')
            if args.getIPinfo:
                r =  requests.get(f'https://ipinfo.io/{ip}/json')
                info = r.json()
                os.makedirs('IPinfo', exist_ok = True)
                ipffn = ip.replace('.','-')
                with open(f'IPinfo{os.sep}\{ipffn}-info.json','w') as f:
                    f.write(r.text)
                city = info['city']
                region = info['region']
                country = info['country']
                loc = info['loc']
                org = info['org']
                postal = info['postal']
                IPtext = f'Country: {country}\nCity: {city}\n'
                if region != city:
                    IPtext += f'Region: {region}\n'
                IPtext += f'Coordinates: {loc}\nISP: {org}\nPostal: {postal}'
                logger.info(f'Following details are known about the IP:\n{IPtext}')
            if args.timeout > 0:
                logger.debug('Cancelling timer')
                timer.cancel()

                t = args.timeout + args.delay
                logger.debug(f'Starting timer ({t}s)')
                timer = threading.Timer(t, handle_timeout)
                timer.start()

        time.sleep(args.delay)
except KeyboardInterrupt:
    sys.exit(0)
finally:
    fd.close()