renew_ovh_dyndns.py

#!/usr/bin/python3

# this script aim to renew an ovh dyndns record
# it musts be executed in cron.
# first it check if DNS is up-to-date
# and then if necessary update the IP
#
# it needs two python packages : requests and dnspython


import sys

import dns.resolver
import requests
from requests.auth import HTTPBasicAuth


def main(hostname, login, password):
    r = requests.get('https://api.ipify.org')
    if r.status_code != 200:
        print("Error while querying public ip")
        return
    ip = r.content.decode("utf-8")
    dns_reverse_ips = dns.resolver.resolve(hostname, 'A')

    if dns_reverse_ips[0].address != ip:
        r = requests.get(f"http://www.ovh.com/nic/update?system=dyndns&hostname={hostname}&myip={ip}",
                         auth=HTTPBasicAuth(login, password))

        if r.status_code != 200:
            print("Error while updating hostname")
            return

        if r.content != f"good {ip}":
            print("error : " + r.content.decode("utf-8"))
            return


if __name__ == '__main__':
    if len(sys.argv) == 4:
        main(sys.argv[1], sys.argv[2], sys.argv[3])
    else:
        print("renew_ovh_dyndns HOSTNAME LOGIN PASSWORD")