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@cherrot
Last active March 16, 2020 08:36
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IPv6 Dynamic DNS (DDNS) for Cloudflare
#!/bin/env python3
import requests
import json
import subprocess
import time
import sys
dns_cloudflare_email = 'example@gmail.com'
dns_cloudflare_api_key = 'YOUR_API_KEY_HERE'
domain = 'example.com'
# your NIC name like eth0, enp30s0. Usually it's fine to leave it empty.
nic_device = ''
def _set_cloudflare_auth_headers():
s.headers['X-Auth-Email'] = dns_cloudflare_email
s.headers['X-Auth-Key'] = dns_cloudflare_api_key
return
# global requests session for a keep-alive connection.
s = requests.Session()
_set_cloudflare_auth_headers()
def get_ipv6_addr() -> str:
addr = subprocess.check_output("ip -o -6 addr show %s scope global dynamic| awk '{print $4}' | cut -d/ -f1 | head -n 1" % nic_device, shell=True)
return addr.strip().decode('ascii')
def _get_cloudflare_results(r:requests.Response) -> list:
r.raise_for_status()
return r.json().get('result', [])
def _get_cloudflare_result(r:requests.Response) -> dict:
res = _get_cloudflare_results(r)
assert len(res) == 1, 'there should be exactly one result'
return res[0]
def fetch_cloudflare_account():
r = s.get('https://api.cloudflare.com/client/v4/accounts')
res = _get_cloudflare_result(r)
account_id, account_name = res.get('id'), res.get('name')
assert account_id is not None and account_name is not None
return account_id, account_name
def fetch_cloundflare_zone_id(account_id:str, account_name:str, domain:str) -> str:
root_domain = domain.rsplit('.', 2)[-2:]
assert len(root_domain)==2
params = {
'name': '.'.join(root_domain),
'status': 'active',
'account.id': account_id,
'account.name': account_name,
}
r = s.get('https://api.cloudflare.com/client/v4/zones', params=params)
res = _get_cloudflare_result(r)
zone_id = res.get('id')
assert zone_id is not None
return zone_id
def fetch_cloundflare_dns(zone_id:str, domain:str, record_type:str = 'AAAA'):
url = 'https://api.cloudflare.com/client/v4/zones/{}/dns_records'.format(zone_id)
params = {'name': domain}
r = s.get(url, params=params)
res = _get_cloudflare_results(r)
dns_id, addr = '', ''
print('Effected DNS records:')
for rc in res:
print('{}\t{}\t{}\t{}'.format(
rc.get('name'), rc.get('type'), rc.get('content'), rc.get('modified_on'),
))
if rc.get('type') == record_type:
dns_id, addr = rc.get('id'), rc.get('content')
return dns_id, addr
def refresh_cloudflare_ipv6_dns(domain:str, addr:str, record_type:str = 'AAAA'):
account_id, account_name = fetch_cloudflare_account()
zone_id = fetch_cloundflare_zone_id(account_id, account_name, domain)
dns_id, effected_addr = fetch_cloundflare_dns(zone_id, domain, record_type)
if effected_addr == addr:
print('No need to update.')
elif dns_id == '':
print('There is no {} record for {} yet. Create one.'.format(record_type, domain))
url = 'https://api.cloudflare.com/client/v4/zones/{}/dns_records'.format(zone_id)
data = {'type': record_type, 'name': domain, 'content': addr, 'ttl': 1}
r = s.post(url, json=data)
r.raise_for_status()
else:
url = 'https://api.cloudflare.com/client/v4/zones/{}/dns_records/{}'.format(zone_id, dns_id)
data = {'type': record_type, 'name': domain, 'content': addr}
r = s.patch(url, json=data)
r.raise_for_status()
return
if __name__ == "__main__":
last_addr = ''
while True:
local_addr = get_ipv6_addr()
delay = 30
if local_addr != last_addr:
print('Detect local IP changed: from "{}" to "{}"'.format(last_addr, local_addr))
print('Refresh remote DNS record.')
try:
refresh_cloudflare_ipv6_dns(domain, local_addr)
last_addr = local_addr
delay = 30
except requests.HTTPError as e:
print('{}\n{}'.format(e, e.response.json()))
delay = 10
print("Retry in {} seconds.".format(delay))
except Exception as e:
print(e)
sys.exit(1)
time.sleep(delay)
# /etc/systemd/system/ddns-ipv6-cloudflare.service
[Unit]
Description=Dynamic DNS for CloudFlare IPv6
After=network.target
Wants=network.target
[Service]
Type=simple
ExecStart=/usr/local/bin/ddns-ipv6-cloudflare.py
Restart=on-failure
# RestartPreventExitStatus=23
[Install]
WantedBy=multi-user.target
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