Cloudflare Dynamic DNS Updater

#!/usr/bin/env python

import argparse
import CloudFlare
import logging
import requests

def public_ip(service='http://ip.mrkc.me'):
    """
    Get the apparent public IP of this computer. This does not imply that the
    necessary network configurations are in place to allow public access.

    Raises Exceptions for anything but a 200 response.

    :param service: the url to perform a GET against (should return only an IP)
    :type  service: str
    :returns: this machine's IP as seen by a server on the Internet
    :rtype: str
    """
    logging.debug("Looking up public IP")
    r = requests.get(service)
    r.raise_for_status()
    logging.debug("Found " + r.text)
    return r.text

def update_cf_dns(cf, name, ip_address):
    # 'AAAA' for IPv6, 'A' for IPv4 (default)
    if ':' in ip_address:
        ip_address_type = 'AAAA'
    else:
        ip_address_type = 'A'
    logging.debug("Address type " + ip_address_type)

    # Get the Zone ID
    logging.debug("Looking up zone id for " + name)
    for zone in cf.zones.get():
        if '.'.join(name.split('.')[-2:]) in zone['name']:
            zone_id = zone['id']
            logging.debug("Found " + zone_id)
            break
    else:
        raise Exception("Unable to find zone id for " + name)

    # Get the DNS record
    logging.debug("Fetching DNS record")
    dns_record = cf.zones.dns_records.get(zone_id,
            params={'name': name, 'match': 'all', 'type': ip_address_type})[0]
    logging.debug("Found " + dns_record['id'])

    # Check to see if the IP has changed
    if dns_record['content'] != ip_address:
        logging.info("Performing DSN record update", dns_record['content'],
                "->", ip_address)
        cf.zones.dns_records.put(zone_id, dns_record['id'],
                data={'name': name,
                    'type': ip_address_type,
                    'content': ip_address})
    else:
        logging.debug("Old Address:" + dns_record['content'] +
                "New Address:" + ip_address)
        logging.info("Not updating")

def main():
    parser = argparse.ArgumentParser()
    parser.add_argument('--email', type=str, required=True)
    parser.add_argument('--token', type=str, required=True)
    parser.add_argument('--domain', type=str, required=True,
            help='the domain name to update')
    args = parser.parse_args()
    logging.basicConfig(format='%(asctime)s %(message)s',
            level=logging.INFO)
    cf = CloudFlare.CloudFlare(email=args.email, token=args.token)
    update_cf_dns(cf, args.domain, public_ip())

if __name__ == '__main__':
    main()

You can then invoke it with a cron job:

*/15 * * * *  /root/updatedns.py --email cfemail@domain.tld --token TOKEN --domain something.com 2>&1 | logger -t "updatedns.py"