gistfile1.rb

  begin
    node_storage = data_bag_item('nodes', node.name)
    requested_revision = node_storage['deployments'].last['revision']
  rescue Net::HTTPServerException
    # data bag item does not exist, create it
    new_node = {
      'id' => node.name,
      'deployments' => [{
        'date'     => Time.now,
        'revision' => 'HEAD',
        'log'      => ''
      }]
    }