test2.rb

#!/usr/bin/ruby

require 'rubygems'
require 'sinatra'
require 'omniauth'
require 'openid/store/filesystem'
require 'openid/fetchers'

OpenID.fetcher.ca_file = '/etc/ssl/certs/ca-certificates.crt'
use Rack::Session::Cookie
use OmniAuth::Builder do
  provider :open_id , OpenID::Store::Filesystem.new('/tmp'), :name => 'google', :identifier => 'https://www.google.com/accounts/o8/id'
end

#### Routes
get '/' do
  <<-HTML
  <a href='/auth/google'>Sign in with Google</a>
  HTML
end

post '/auth/:name/callback' do
  auth = request.env['omniauth.auth']
  auth['user_info']['name']
end

get '/auth/failure' do
    "Authentication Failed"
end