Use the Digital Ocean DNS API to implement dynamic DNS

digitalocean_dynamic_dns.py

#!/usr/bin/env python3
## Setup:
##  0. See if you have a better way than the default below to find your WAN IP
##  1. Create the record using the control panel manually, set ttl to 30 or 60, set to dummy IP
##  2. Create an API token specific to this application
##  3. pip/pip3 install requests
##  4. Update the variables below and add cron job

# config
base = 'https://api.digitalocean.com/v2'
domain = 'YOUR_DOMAIN'
domain_name = 'YOUR_HOSTNAME'
token = 'YOUR_API_TOKEN'

import requests

# the following default for obtaining WAN IP will work fine
# however if this 3rd party site is ever compromised or turns malicious,
# you and your users could be compromised. A higher security method is
# recommended

wan_ip = requests.get('https://icanhazip.com').text.strip()

# this is what i use to get my WAN IP
# SSH's to my router utilizing SSH key for auth and uses the same method
# that onboard dynamic DNS uses
# (setting up persistant storage on the router to run this there seemed annoying)

#from subprocess import check_output
#wan_ip = check_output(['ssh', '[email protected]', 'nvram', 'get', 'wan0_ipaddr']).decode('utf-8').strip()

## main

auth_headers = {'Authorization': f'Bearer {token}'}

records = requests.get(f'{base}/domains/{domain}/records', headers=auth_headers).json()

record_id = None
for rec in records['domain_records']:
    if rec['name'] == domain_name:
        record_id = rec['id']
        break

if not record_id:
    raise Exception(f'Could not find {domain_name}.{domain}')

requests.put(f'{base}/domains/{domain}/records/{record_id}', headers=auth_headers,
             json={'data': wan_ip})

print(f'Updated {domain_name}.{domain} to {wan_ip}')