rack proxy for OpenERP integration in Rails app

application.rb

require 'rack-proxy'

class AppProxy < Rack::Proxy
  def initialize(app)
    @app = app
  end

  def call(env)
    if env['PATH_INFO'] == "/shop"
      [301, {"Location" => "/"}, self]
    elsif env['PATH_INFO'] =~ %r{^/web} || env['PATH_INFO'] =~ %r{^/shop}
      rewrite_response(perform_request(rewrite_env(env)))
    else
      @app.call(env)
    end
  end

  def rewrite_env(env)
    env["HTTP_HOST"] = "localhost:8069"
    env
  end

  def extract_http_request_headers_with_hack(env)
    headers =  extract_http_request_headers_without_hack(env)
    headers.delete("IF-NONE-MATCH") # don't ask me why but this is required
    headers.merge!("HOST" => "localhost:9292") # preserve host, required
  end

  alias_method :extract_http_request_headers_without_hack, :extract_http_request_headers
  alias_method :extract_http_request_headers, :extract_http_request_headers_with_hack

end

config.middleware.insert 0, AppProxy