strato-ddns/src/ddns_update.py

83 lines
2.0 KiB
Python
Executable File

#!/usr/bin/python3
import logging
import requests
from requests.exceptions import RequestException
import click
from os import environ
from netifaces import interfaces, ifaddresses, AF_INET6
from ipaddress import ip_address
from time import sleep
logging.basicConfig(level=logging.INFO)
log = logging.getLogger("ddns updater")
def get_global_address(address_family):
for interface in interfaces():
if_addresses = ifaddresses(interface)
if address_family in if_addresses:
for address in if_addresses[address_family]:
addr = ip_address(address["addr"].split("%")[0])
if addr.is_global:
return addr
return None
def get_global_ipv6():
return get_global_address(AF_INET6)
def response_successful(response_text):
return response_text.startswith("good") or response_text.startswith("nochg")
def ddns_update(host, key, ip):
url = f"https://dyndns.strato.com/nic/update?hostname={host}&myip={ip}"
try:
response = requests.get(url, auth=(host, key), timeout=3)
response.raise_for_status()
if not response_successful(response.text):
raise RequestException("update failed")
except RequestException as error:
log.error(response.text.strip())
log.error(error)
return False
log.debug(response.text.strip())
log.info("update successful")
return True
@click.command()
@click.option(
"--host",
required=True,
default=lambda: environ.get("DDNS_HOST", None),
help="The dns name to update",
)
@click.option(
"--key",
required=True,
default=lambda: environ.get("DDNS_KEY", None),
help="The ddns authorization key",
)
def loop_ddns_update(host, key):
last_ip = None
while True:
current_ip = get_global_ipv6()
if current_ip != last_ip:
if ddns_update(host, key, current_ip):
last_ip = current_ip
else:
log.debug("skipped update, ip address unchanged")
sleep(30)
if __name__ == "__main__":
loop_ddns_update()