Enabling DNS split authority with OctoDNS

Secondary DNS functionality is usually implemented with AXFR which doesn't support advanced functionality like Geo DNS and also limits the providers you can choose as only a few offer it.

It also doesn't help with managing the records in the primary provider, requiring either working in a UI or writing using software like OctoDNS to manage it. It's definitely a good option for simpler and stable setups, neither of which is the case for us or many of the people I've talked to. If it fits a situation you have it's worth exploring.

There's an article on ZDnet, http://www.zdnet.com/article/github-open-sources-octodns-new... that does a good job of covering some of the reasons for it that is probably relivant to this.

Yeah. That's definitely something we looked closely at. I'd say the main difference is that OctoDNS abstracts away the details of the specific provider so that you write a single config that can be pushed to one or more places and changed over time without having to touch the records themselves.

Terraform requires creating a resource for each record and provider pair. It's good for orchestrating a single provider especially when you're otherwise creating associated resources with Terraform.

The custom DSL for each provider varies thought and I wasn't happy with my attempts at trying to abstract away which provider(s) things were going to using modules. The result wasn't simple enough that anyone at the company, not just engineers, could submit a PR for.

Terraform is great, but requires N number of definitions for each DNS record. (where N is the number of DNS providers).

I believe OctoDNS abstracts multiple providers so you just define a single DNS record.

There is support for sourcing data from djbdns config files, https://github.com/github/octodns/blob/master/octodns/source..., but not writing it out to that format currently. It shouldn't be too difficult for someone to add when they have a specific need it. Same goes for other software and providers.

There is a PowerDNS provider, https://github.com/github/octodns/blob/master/octodns/provid... which we use for some internal DNS purposes. We actually plan to talk about that in a future post to compliment this one's focus on our external DNS setup.

A lot of thought was put into making it relatively easy to add new ones. Writing the tests is generally the most involved part. There's a plan to add a doc on creating a new provider which I/we will hopefully get to soon.

The main reason was the YAML config file could be easily understood. Since switching things over to use OctoDNS a couple months ago we've had nearly 75 PRs to make changes, mostly internal/testing/dev, but plenty of real stuff too. I don't have an exact number, but skimming over those there's probably ~25 people who have made those PRs.

In order to make it possible for anyone at the company to make PRs, not just SRE team members, we had to minimize or eliminate the learning curve and YAML was the best option for that we could think of. In the past those 75 PRs would have instead been issues asking an engineer on the infrastructure team to make the changes. It's been a huge and positive shift.