How to get the subdomain value from a url?

Question

how can I get the subdomain value in rails, is there a built-in way to do this?

e.g.

test123.example.com

I want the test123 part of

Answer 1

Rails 3.0 has this capability built-in, you can access the subdomain from request.subdomain.

You can also route based on the subdomain:

class SupportSubdomain
  def self.matches?(request)
    request.subdomain == "support"
  end
end

Basecamp::Application.routes do
  constraints(SupportSubdomain) do
    match "/foo/bar", :to => "foo#bar"
  end
end

If you're using 2.3, you'll need to use a plugin such as subdomain-fu.

Answer 2

Use the following method inside your controller

request.subdomains

This Returns an array of subdomains

Answer 3

In case you are working with a string, and assuming it can be a true URI, you can do this to extract the subdomain.

require 'uri'

uri = URI.parse('http://test123.example.com')
uri.host.split('.').first
=> "test123"

https://stackoverflow.com/a/13243810/3407381

Answer 4

You can use the SubdomainFu plugin. This plugin gives you a method current_subdomain which returns the current_subdomain of your app.

You can also have a look at this Railscast

UPDATE

You can also use request.subdomains this will give you an array of subdomains.

Answer 5

A bit late to the party but here's what I used in older versions of rails.

subdomain = request.subdomains.join('.')

It should be backwards compatible in newer versions

Answer 6

account_location is also a good plugin. After using it, you can find the account based on different subdomains. And you can find out subdomain from url just by writing

request.subdomains(0).first

in your code.