Cloudflare DDNS (Dynamic DNS) - UniFi OS

UnFi OS has in-built support for DDNS for WAN connections but Cloudflare is not supported OOTB. This Cloudflare Worker is designed to provide the intermediary support required to allow UnFi OS to update Cloudflare using the OOTB options.

This Cloudflare Worker accepts parameters specified under Settings > Internet > WAN > Dynamic DNS > custom which UniFi OS uses to call whenever an IP change is detected. The Cloudflare Worker then calls Cloudflare DNS API to update the specified DNS A record with the new IP address.

Based on the implementation from - https://github.com/willswire/unifi-ddns⁠ - Thanks!

Updated 22-08-2024 - Added Telegram Notifications

Cloudflare requirements

You need to be using Cloudflare for you domain which means using Cloudflare nameservers and managing your domains DNS within Cloudflare.

Install the Cloudflare Worker

1. Deploy the Worker using the Cloudflare dashboard
2. In the Cloudflare Workers dashboard - note the \*.workers.dev URL
3. Create a Cloudflare API token to update DNS records -
   • https://dash.cloudflare.com/profile/api-tokens
   • Click Create token, select Create custom token
   • Choose Zone > DNS > Edit for permissions, and include your zone under Zone Resources
   • Copy the API Key which will be used later

Install with Cloudflare Wrangler CLI

1. Clone or download this project
2. Ensure you have Cloudflare [Wrangler CLI](https://developers.cloudflare.com/workers/wrangler/install-and-update/) installed
3. Log in with Cloudlfare Wrangler and run wrangler deploy
4. Note the \*.workers.dev URL after creation
5. Create an API token mentioned above

Telegram Notifications

The latest update includes support for Telegram notifications. Two environment variables are required for this to work.

1. telegramBotToken
2. telegramChatId

These need to be created as environment variables on the Cloudflare Worker.

Configuring UniFi OS

1. https://unifi.ui.com/
2. Click Settings > Internet > WAN > Dynamic DNS
3. Click Create New Dynamic DNS and enter the following parameters -
   • Service: Choose custom
   • Hostname: DNS record to update in subdomain.domain.com format to update (example - subdomain.domain.com or domain.com for root)
   • Username: Domain name (example domain.com)
   • Password: Cloudflare API Token as created above
   • Server: Cloudflare Worker URL <worker-name>.<worker-subdomain>.workers.dev/update?ip=%i&hostname=%h

Testing on a UDM-Pro

Test the setup and force a manual update on a UDM-Pro -

1. SSH into your the UDM-Pro device
2. Run ps aux | grep inadyn
3. Note the configuration file path which looks similar to /run/ddns-eth4-inadyn.conf
4. Run inadyn -n -1 --force -f <config-path> (example - inadyn -n -1 --force -f /run/ddns-eth4-inadyn.conf)
5. Check the response and Cloudlare DNS or Cloudflare Worker logs
6. /var/log/messages can also be checked error messages

Troubleshooting

• For subdomains (example - subdomain.domain.com) - create an A record manually in Cloudflare DNS first.
• For errors with hostname resolution (inadyn[2173778]: Failed resolving hostname https: Name or service not known), remove https:// from the Server field
• If a second domain is required - Create New Dynamic DNS in UniFi OS and use the service dyndns with the same setup as above