How do I implement a redirects-only rack-based heroku application?

Question

I would like to create an rack application for deployment of heroku to create some 301 redirects to other subdomains.

If the path would be carried over, it would be nice.

I started with the following code, but it isn't working:

require 'rack-force_domain'

use Rack::ForceDomain, ENV["DOMAIN"]

run lambda { |env| [200, {'Content-Type'=>'text/plain'}, StringIO.new("Hello World!\n")] }

Answer 1

I solved this problem by using sinatra finally. That's my config.ru:

require 'sinatra'

get %r{(.*)} do
  redirect to("http://custom.domain#{params[:captures].first}"), 301
end

run Sinatra::Application