Multiple domains powered by one rails app

Question

I am creating a blogging-like application where we allow our customers to use their own custom domain names such as domainexample.com, so each different domain serves the same application but with different content.

However I am struggling to figure out how to set this up on a production server. If my production server has a static IP then I can surely just set an a-record on each domain to the ip of the production server.

But what if the production server does not have a static IP. For example if we want to host it on heroku or engineyard? I have seen a few solutions online that require using rewrite rules but they require server restarts and cant really dynamically add and remove new domains as new users sign up. Does anyone know any good solutions to let multiple domains hit one rails app?

Answer 1

Heroku isn't your only option. If you can anticipate your customer's domains, have a look at this. If you can't, Rails routes constraints and a combination of the accepted answer to the question linked above should get you where you need to be going. Sounds like you wouldn't want to restart your server--so no editing of the routes. You might also make domains part of your models, or distinguish at the controller level or use URL rewriting in your web-server layer.

The problem, as I see it, is that Rails breaks its mantra of opinion over configuration here. There are many ways of serving up from multiple domains. That might be an intrinsic complexity, but the Rails Guides could at least document one possible solution.