Cloudflare DDNS for UniFi OS

A Cloudflare Worker script that provides a UniFi-compatible DDNS API to dynamically update the IP address of a DNS A record.

Why?

UniFi Dream Machine Pro (UDM-Pro) or UniFi Security Gateway (USG) users may need to update Cloudflare domain name DNS records when their public IP address changes. UniFi does not natively support Cloudflare as a DDNS provider.

Configuring Cloudflare

Ensure you have a Cloudflare account and your domain is configured to point to Cloudflare nameservers.

Install With Click To Deploy

1. Deploy the Worker:
2. Navigate to the Cloudflare Workers dashboard.
3. After deployment, note the \*.workers.dev route.
4. Create an API token to update DNS records:
   • Go to 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 your API Key for later use in UniFi OS Controller configuration.

Install With Wrangler CLI

1. Clone or download this project.
2. Ensure you have Wrangler CLI installed.
3. Log in with Wrangler and run wrangler deploy.
4. Note the \*.workers.dev route after creation.
5. Create an API token as described above.

Configuring UniFi OS

1. Log in to your UniFi OS Controller.
2. Navigate to Settings > Internet > WAN and scroll down to Dynamic DNS.
3. Click Create New Dynamic DNS and provide:
   • Service: Choose custom.
   • Hostname: Full subdomain and hostname to update (e.g., subdomain.mydomain.com or mydomain.com for root domain).
   • Username: Domain name containing the record (e.g., mydomain.com).
   • Password: Cloudflare API Token.
   • Server: Cloudflare Worker route <worker-name>.<worker-subdomain>.workers.dev/update?ip=%i&hostname=%h.
     • For older UniFi devices, omit the URL path.
     • Remove https:// from the URL.

Testing Changes - UDM-Pro

To test the configuration and force an update on a UDM-Pro:

1. SSH into your UniFi device.
2. Run ps aux | grep inadyn.
3. Note the configuration file path.
4. Run inadyn -n -1 --force -f <config-path> (e.g., inadyn -n -1 --force -f /run/ddns-eth4-inadyn.conf).
5. Check /var/log/messages for related error messages.

Testing Changes - USG

To test the configuration and force an update on a USG:

1. SSH into your USG device.
2. Run ls /run/ddclient/ (e.g.: /run/ddclient/ddclient_eth0.pid)
3. Note the pid file path as this will tell you what configuration to use. (e.g.: ddclient_eth0)
4. Run sudo ddclient -daemon=0 -verbose -noquiet -debug -file /etc/ddclient/<config>.conf (e.g., sudo ddclient -daemon=0 -verbose -noquiet -debug -file /etc/ddclient/ddclient_eth0.conf).
5. This should output SUCCESS when the DNS record is set.

Important Notes!

• For subdomains (sub.example.com), create an A record manually in Cloudflare dashboard first.
• If you encounter a hostname resolution error (inadyn[2173778]: Failed resolving hostname https: Name or service not known), remove https:// from the Server field.