What's the best way to get the hostname from the env hash in a Rails app?

Question

I'm writing an OmniAuth dynamic provider and in the callback I need to get the current hostname (the app works in several different hostnames). I don't have the request object, just a big env hash. I found this hash contains an entry, env["SERVER_NAME"], with the hostname, but I'm not sure if that's a stable entry or it may change depending on the web server or stuff like that.

I also found the hostname buried in env["action_dispatch.routes"] in the member variable @host.

Any ideas what's the best or canonical way to get the hostname at this point?

Answer 1

The app is not in production yet, but so far the the private beta, using env["SERVER_NAME"] worked like a charm.

Answer 2

In a rails controller, you can simply use:

request.host

Though I'm not sure if that sources anything different from what you already looked at. This works fine for me in a Rails 3.1 app I'm working on.