Script renouvellement de dyndns

renew_dyndns

#!/usr/bin/python3

# this script aim renew an ovh dyndns
# it musts be executed in cron,
# first it check if DNS is update
# 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
import time
import socket
import requests.packages.urllib3.util.connection as urllib3_cn

#Force IPv4
def allowed_gai_family(): 
    return socket.AF_INET

def main(hostname, login, password):

    i = 0;
    while i < 3:
        try:
            r = requests.get('http://ifconfig.me/ip')
            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:
                print(f"IP Change new : {ip}, old : " + dns_reverse_ips[0].address)

                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.decode("utf-8").strip() != f"good {ip}":
                    print("error : " + r.content.decode("utf-8"))
                    return
                else:
                    print("IP well registered")
            else:
                return
        except Exception as e:
            if x >= 3:
                print(e)
                print("catch exception " + i + " time")
            else:
                time.sleep(30)
        i += 1

if __name__ == '__main__':

    urllib3_cn.allowed_gai_family = allowed_gai_family
    if len(sys.argv) == 4:
        main(sys.argv[1], sys.argv[2], sys.argv[3])
    else:
        print("renew_ovh_dyndns HOSTNAME LOGIN PASSWORD")