EmberController.rb

class EmberController < ApplicationController
  def app
    content = bootstrap_index(params[:revision])
    render html: content.html_safe
  end

  private

  def project_name
    'dashboard'
  end

  def bootstrap_index(index_key = nil)
    index_key &&= "#{project_name}:index:#{index_key}"

    index_key ? load_index(index_key) : bootstrap_current
  end

  def bootstrap_current
    index_key = redis.get("#{project_name}:index:current")
    index_key = "#{project_name}:index:#{index_key}"
    load_index(index_key)
  end

  def load_index(index_key)
    redis.get(index_key) ||
      raise("No Ember app deployed at key '#{index_key}'")
  end

  def redis
    @_redis ||= begin
      redis_url = { url: "#{ENV['REDIS_URL']}" }
      Redis.new(redis_url)
    end
  end
end