Managing DNS records the DevOps way

Posted on: 2018/04/19 Tags: dns dnscontrol

Managing DNS records has always been a bit of a hassle for me. Most DNS providers have some sort of web gui where you have to manually fiddle in all records manually. Besides the fact that this is really tedious, this is quite error-prone. Humans are horrible at doing manual work! So let’s automate this!

My first iteration was moving everything to AWS Route53. Amazon provides APIs for all of their services, but unfortunately they are horribly complicated!

So in the next iteration I moved everything to Google Cloud. They also provides APIs and they’re much easier to use! You can build a DynDNS-like service in a couple of lines.

The third iteration was when I discovered DnsControl. It allows you to define DNS records using a small DSL, and then push those changes to your DNS providers using a small CLI tool.

In a nutshell, it works like this: You define your DNS zones and records in a file called dnsconfig.js, provide credentials for your DNS provider, and then run dnsconfig push to push those records to your Provider.

An example config could look like this:

var REG_NONE = NewRegistrar('none', 'NONE')
var GCLOUD = NewDnsProvider('gcloud', 'GCLOUD')

D('', REG_NONE, DnsProvider(DNS_BIND),
    A('@', ''),
    A('test', '')

See the DnsControl Getting Started guide for a more complete example.

I really like DnsControl for various reasons:

  • It allows you to define DNS records as code, which means you can write scripts that automatically generate the required code.
  • Having your config as code means you can put it in Git! I love putting stuff in Git because it makes it so forgiving to try out new stuff when you can easily recover the last working state with a couple of keystrokes.
  • It works with many different providers, which makes it easy to move from one to another. Not happy with Google anymore? Replace the provider in your dnsconfig.js and dnscontrol push - done! You can even push your zones to multiple providers at the same time if you want to be on the safe side.
  • When pushing the records, DnsControl will remove any records not in dnsconfig.js anymore. This really helps with keeping your zones cleaned up!

And that’s it! In the next post, I describe how to further automate our setup and automatically deploy each change!