test_kitchen_sharing_node_data_in_clusters.rb

# chef-nodes is useful to share a nodes attributes with other nodes. if you want to share _converged_ node
# data (more than just ip and hostname from chef-nodes) then you can use test-kitchen >= 1.20.0 which adds
# support for downloading files from nodes after converge via .kitchen.yml:
# 
# provisioner:
#   nodes_path: test/fixtures/nodes
#   downloads:
#     /tmp/kitchen/nodes: test/fixtures/
# 
# this will download node data after converge and drop it into test/fixtures/nodes/node-a.json, node-b.json, etc
# all these files will be uploaded to the next node to converge by chef-nodes.
# unfortunately chef-nodes resets these node files when a converge starts by default. this patch will disable that:

require 'kitchen/provisioner/chef_zero'

module Kitchen
  module Provisioner
    # Patch kitchen-nodes to not delete node files before converge. This
    # ensures all node files will be uploaded during concurrent provisions.
    # https://github.com/mwrock/kitchen-nodes/blob/master/lib/kitchen/provisioner/nodes.rb
    class Nodes < ChefZero
      def create_sandbox
        create_node
      ensure
        super
      end
    end
  end
end

# you can do the same thing with data_bags. for example if node-a modifies a data bag item then
# node-b has to read from it, just specify to also download data_bags from nodes after converge:
# 
# provisioner:
#   name: nodes
#   data_bags_path: test/fixtures/data_bags
#   downloads:
#     /tmp/kitchen/data_bags: test/fixtures/