This post details my switch over to using Powershell and Cloudflare to update a DNS record to a server’s current IP. This effectively emulates dyndns for this host – except it’s free.
There are a load of other options out there, which even include some simple-but-quite-clunky apps for domain registrars like NameCheap; but installing third party software is not the route I want to take.
I previously had my target domain (let’s call it targetdomain.com) hosted on a Linux box, and used SSH to update the DNS settings via a Windows server. This worked well for three years without a blip – but was clunky. I was using a scheduled task to start a bat file, which then ran Putty to run the shell script…to update a config on a server which was only hosting the domain to serve this purpose.
I’ve been using Cloudflare for years, and set aside time to write a script to use their service for this purpose. As it turns out, people have done this for years – so I’ve taken one off the shelf.
To use the script (which is a Powershell module) available on GitHub, I dropped it over to the windows server, and imported it.
To do this, I copied the file into the all users directory (check $Env:PSModulePath if it’s unknown).
You can then import the module and check it’s available
PS cd C:\Program Files\WindowsPowerShell\Modules\CloudFlareDynamicDns PS Import-Module .\CloudFlareDynamicDns PS Get-Module
Setting up our task
I’m using task scheduler for this, as it’s straight forward and easy to use. To test this, I simply ran the command on Powershell directly, which works. After, I switched it to calling it from a file and added some logging.
At the current time, the two things on my mind are:
- There’s no failure notifications (this feature is easily added however)
- The Cloudflare API requires use of your full account key. It’s very surprising you can’t create per-site keys, but it looks like this is in the works and expected at some point in 2019
- Cloudflare API Help: https://api.cloudflare.com/
- The module author’s post: https://blog.netnerds.net/2015/12/use-powershell-and-cloudflare-api-v4-to-dynamically-update-cloudflare-dns-to-your-external-ip/