how to run rake tasks asynchronously from controllers by spawning child processes

async_rake.rb

class ApplicationController < ActionController::Base

  def perform_async(task, options = {})
    options[:rails_env] ||= Rails.env
    env_vars = options.map { |key, value| "#{key.to_s.upcase}='#{value.to_s}'" }
    env_vars_string = env_vars.join(' ')
    Process.fork {exec("#{env_vars_string} bin/rake #{task}")}
  end

end