Simple bash script to keep Cloudflare A record up to date with your current global ip.

Useful for servers without a static ip.

You will need jq and curl to run the script.

On Debian/Ubuntu:

apt-get install -y curl jq

Put ddns somewhere (on your path if you want) and make it executable.

curl -o /path/to/ddns https://raw.githubusercontent.com/claudetech/cloudflare-ddns/master/ddns
chmod +x /path/to/ddns

Create a file with the EMAIL and TOKEN variables containing your Cloudflare email and API key. The default path is /etc/cloudflare/default but you can override it with the DNS_ENV variable.

You can also set the ZONE and DOMAIN variables for the A record you want to keep up to date, or pass the variables directly when executing the script.

You can find an example config in dns_env.example.

Do not forget to set the permission to 600 on the file, to avoid having your Cloudflare API key read.

You can then run the script with:

DNS_ENV=/path/to/config ZONE=example.com DOMAIN=foo.example.com /path/to/ddns

You can omit ZONE and DOMAIN if you wrote them in the config file.

Note that it will not work if DOMAIN does not have an A record associated.

To keep your A record up to date, you can add the task to your crontab. After running crontab -e, add the following.

* * * * * DNS_ENV=/path/to/config /path/to/ddns 2>&1 >> /path/to/logfile

This will execute the script every minute.