Gandi Dynamic DNS

Cron job to auto update a DNS record when WAN IP changes using Gandi Live DNS API on Debian GNU/Linux

To install

git clone https://gitlab.com/lab.8916100448256/gandi-dynamic-dns.git ./gandi-dynamic-dns
cd ./gandi-dynamic-dns
sudo bash ./install.sh

Then configure DNS record info and API key in file /etc/live-dns/live-dns.conf

How it works

/etc/cron.d/live-dns-update

Cron job definition to check for WAN IP change and call Live DNS API to update the DNS record if necessary. By default runs the check/update script 2 times per hour, at every hour past 12 and 42 minutes.

/etc/live-dns/live-dns.conf

Configuration file for the check/update script Needs to contains 3 environment variable definitions

• DOMAIN="domain.tld" : Replace domain.tld with your domain name
• RECORD="host" : Replace host with the sub domain you want to update when WAN IP changes
• APIKEY="Your-API-Key" : Replace with you API key generated on the Gandi web interface.

Check this page if you don't know your APIKey : https://docs.gandi.net/en/domain_names/advanced_users/api.html

/usr/local/bin/live-dns-update.sh

This is the script that is called by the cron job.

First the WAN (external) IPV4 and IPV6 adresses are determined using http://me.gandi.net Then they are compared to DNS records for the configured host and domain. In case of mismatch Gandi live DNS API is called to update the DNS records

This script is based on this sample provided by Gandi on their GitHub : mywanip.sh