cloudflare-dyndns-updater

Simple script to update A and AAAA records to the current public IP of your server via the Cloudflare API.

What this script does

1. Automatically gests the current public IPv4 and IPv6 adress of your Server via https://cloudflare.com/cdn-cgi/trace
2. Sets the A and AAAA records for the domains that you specified in the script to the current public IPv4 and IPv6 Adress that we got in the first step.

Prerequisites

• To configure this script, edit the variables in the "Config" section. Variables:
  • domain_names
    • This is a newline separated list of subdomains that you want to update. They have to belong to the same zone, i.e. be either the domain name itself or a subdomain.
    • All A and AAAA records you want to update via this script have to already exist.
      • To create them, go to “Websites" -> Select your Domain -> expand the "DNS" entry on the left side -> "Records" -> "Add record"
  • zone_id
    • The Zone ID of your Domain
    • You get it via “Websites" -> Select your Domain -> The ID is written on the right side under the "API" headline.
  • api_token
    • This token gives the script the access to update the DNS records of the Domain.
    • To get one, go here: Top right (whre you can also log out) -> "My Profile" -> "API Tokens" -> "Create Token" -> "Edit zone DNS" -> Under "Zone Resources" select your Domain in the last column. -> "Continue to summary" -> Create Token -> Now copy the token and add it to the script.

Installing

You can run this script as a normal user by just executing it. If you want it to run automatically, I suggest this setup:

• Copy the ddns.sh script to the /opt folder
  • sudo cp ddns.sh /opt
• Set the owner to root and make it only readable for root (so that other users can't steal your API Token)
  • sudo chown root:root /opt/ddns.sh
  • sudo chmod 700 /opt/ddns.sh
• Copy the content of the "systemd" folder to /etc/systemd/system
  • sudo cp systemd/* /etc/systemd/system
• Now start the timer, so that your DNS records get updated every 15 minutes
  • sudo systemctl enable --now ddns.timer