chef deploy resource activate workaround

gistfile1.rb

deploy_resource = deploy_revision "/var/www" do
 [..snip..]
end

ruby_block "activate deploy" do
  block do
    Dir.chdir("/var/www/shared/cached-copy")
    activated = File.basename( File.readlink( "/var/www/current" )) ==
      `git rev-parse HEAD`.strip
    if !activated
      deploy_resource.run_action( :force_deploy )
    end
  end
end