pustak_controller.rb

class PustakController < ApplicationController

before_filter :session_expires, :except => [:login, :logout]
before_filter :update_session_time, :except => [:login, :logout]

  def index
  end

  def session_expires
    @time_left = (session[:expires_at] - Time.now).to_i
    unless @time_left > 0
      reset_session
      redirect_to login_path
    end
  end

  def update_session_time
    session[:expires_at] = 10.seconds.from_now
  end

end