ip_lookup.py

# coding=utf-8
from os import path
from time import sleep
from urllib.request import urlopen
from datetime import datetime
from smtplib import SMTP
from bs4 import BeautifulSoup

DEBUG_TAG = '[{name}]'.format(name=path.basename(__file__))
IP_LOOKUP_URL = 'http://whatismyip.org'


def get_external_ip(url: str) -> str:
    """

    :param url:
    :return: the new ip
    """
    ext_ip = urlopen(url).read()
    soup = BeautifulSoup(ext_ip, "html.parser")

    try:
        return soup.span.string
    except Exception:
        log_debug(str(Exception))


def send_email(host='localhost',
               recipients='[email protected]',
               sender='[email protected]',
               msg=''):
    """

    :param host:
    :param recipients:
    :param sender:
    :param msg:
    """
    try:
        session = SMTP(host)
        session.sendmail(sender, recipients, msg)
        log_debug('Sending IP Update email to: {emails}', emails=recipients.split(','))
        session.quit()
        log_debug('Successfully sent!')
    except Exception:
        log_debug(str(Exception))


def log_debug(msg: str, **kwargs):
    """
    Logs out what the script is doing in a nice formatted fashion.

    Use a real logging library to get anymore complex than this.

    :param msg: the log message as a formatted string
    :param kwargs: custom data to add to log message
    :return:
    """
    print('{time}\t{tag}:\t{msg}'.format(tag=DEBUG_TAG, time=datetime.now(), msg=msg.format(**kwargs)))


if __name__ == "__main__":
    before_ip = get_external_ip(IP_LOOKUP_URL)

    log_debug('Starting up IP Updater')
    log_debug('Starting IP is: {bip}', bip=before_ip)

    while True:
        log_debug('Fetching external IP from: {url}', url=IP_LOOKUP_URL)
        after_ip = get_external_ip(IP_LOOKUP_URL)

        if before_ip == after_ip:
            log_debug('IP is still {ip}. Checking again in an hour...', ip=after_ip)
            sleep(3600)
        else:
            log_debug('IP changed! New IP is: {aip}', aip=after_ip)
            send_email(msg='Subject: %s\n\n%s' % ("Sir, New IP", "Your new IP is {ip}.".format(ip=after_ip)))

        sleep(5)