Demonstration of a bug where a node is incorrectly indexed as having a role that it does not

chef-expander-role-promotion-bug-demonstration.rb

#!/usr/bin/env ruby

# POC for: https://github.com/chef/chef-server/issues/718

# Demonstration of a bug where a node is incorrectly indexed as having a role that it does not.
#
# 1. chef-expander munges and flattens the node hash
#
# 2. if the node has "role" as a nested keys, it will be promoted and merged with the top
#
# 3. SOLR interprets this as the node having that role, so the node is incorrectly listed in the results of `knife search role:guest`
#
#
# The danger is if you happen to have a collision with a real role name.  Then, a command like this would execute on unexpected servers:
#
#    knife ssh "role:guest" "sudo service foo stop"
#
#
# The issue described above was probably the cause of: https://tickets.opscode.com/browse/CHEF-2902
#

require 'fast_xs'  # gem install fast_xs -v 0.7.3
require 'json'
require 'pp'

module Chef
  module Expander
    # From: https://github.com/chef/chef-expander/blob/14b11a/lib/chef/expander/flattener.rb

    # Flattens and expands nested Hashes representing Chef objects
    # (e.g, Nodes, Roles, DataBagItems, etc.) into flat Hashes so the
    # objects are suitable to be saved into Solr. This code is more or
    # less copy-pasted from chef/solr/index which may or may not be a
    # great idea, though that does minimize the dependencies and
    # hopefully minimize the memory use of chef-expander.
    class Flattener
      UNDERSCORE              = '_'
      X                       = 'X'

      X_CHEF_id_CHEF_X        = 'X_CHEF_id_CHEF_X'
      X_CHEF_database_CHEF_X  = 'X_CHEF_database_CHEF_X'
      X_CHEF_type_CHEF_X      = 'X_CHEF_type_CHEF_X'

      def initialize(item)
        @item = item
      end

      def flattened_item
        @flattened_item || flatten_and_expand
      end

      def flatten_and_expand
        @flattened_item = Hash.new {|hash, key| hash[key] = []}

        @item.each do |key, value|
          flatten_each([key.to_s], value)
        end

        @flattened_item.each_value { |values| values.uniq! }
        @flattened_item
      end

      def flatten_each(keys, values)
        case values
        when Hash
          values.each do |child_key, child_value|
            add_field_value(keys, child_key)
            flatten_each(keys + [child_key.to_s], child_value)
          end
        when Array
          values.each { |child_value| flatten_each(keys, child_value) }
        else
          add_field_value(keys, values)
        end
      end

      def add_field_value(keys, value)
        value = value.to_s
        @flattened_item[keys.join(UNDERSCORE)] << value
        @flattened_item[keys.last] << value
      end
    end

    # Modified version of: https://github.com/chef/chef-expander/blob/14b11a/lib/chef/expander/solrizer.rb#L158-L208
    class Solrizer
      ADD     = "add"
      DELETE  = "delete"
      SKIP    = "skip"

      ITEM        = "item"
      ID          = "id"
      TYPE        = "type"
      DATABASE    = "database"
      ENQUEUED_AT = "enqueued_at"

      DATA_BAG_ITEM = "data_bag_item"
      DATA_BAG      = "data_bag"

      X_CHEF_id_CHEF_X        = 'X_CHEF_id_CHEF_X'
      X_CHEF_database_CHEF_X  = 'X_CHEF_database_CHEF_X'
      X_CHEF_type_CHEF_X      = 'X_CHEF_type_CHEF_X'

      CONTENT_TYPE_XML = {"Content-Type" => "text/xml"}

      START_XML   = "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n"
      ADD_DOC     = "<add><doc>"
      DELETE_DOC  = "<delete>"
      ID_OPEN     = "<id>"
      ID_CLOSE    = "</id>"
      END_ADD_DOC = "</doc></add>\n"
      END_DELETE  = "</delete>\n"
      START_CONTENT = '<field name="content">'
      CLOSE_FIELD = "</field>"

      FLD_CHEF_ID_FMT = '<field name="X_CHEF_id_CHEF_X">%s</field>'
      FLD_CHEF_DB_FMT = '<field name="X_CHEF_database_CHEF_X">%s</field>'
      FLD_CHEF_TY_FMT = '<field name="X_CHEF_type_CHEF_X">%s</field>'
      FLD_DATA_BAG    = '<field name="data_bag">%s</field>'

      KEYVAL_FMT = "%s__=__%s "

      # Takes a flattened hash where the values are arrays and converts it into
      # a dignified XML document suitable for POST to Solr.
      # The general structure of the output document is like this:
      #   <?xml version="1.0" encoding="UTF-8"?>
      #   <add>
      #     <doc>
      #       <field name="content">
      #           key__=__value
      #           key__=__another_value
      #           other_key__=__yet another value
      #       </field>
      #     </doc>
      #   </add>
      # The document as generated has minimal newlines and formatting, however.
      def self.pointyize_add(flattened_object)
        xml = ""
        xml << START_XML << ADD_DOC
        xml << (FLD_CHEF_ID_FMT % @obj_id)
        xml << (FLD_CHEF_DB_FMT % @database)
        xml << (FLD_CHEF_TY_FMT % @obj_type)
        xml << START_CONTENT
        content = ""
        flattened_object.each do |field, values|
          values.each do |v|
            content << (KEYVAL_FMT % [field, v])
          end
        end
        xml << content.fast_xs
        xml << CLOSE_FIELD      # ends content
        xml << (FLD_DATA_BAG % @data_bag.fast_xs) if @data_bag
        xml << END_ADD_DOC
        # @xml_time = Time.now.to_f - @start_time
        xml
      end
    end
  end
end


obj = JSON.parse(DATA.read)

warn "After Flattener:"
warn "----------------------------------------"
e = Chef::Expander::Flattener.new(obj).flattened_item
pp e


warn ""
warn "After Solrizer (roughly):"
warn "----------------------------------------"
s = Chef::Expander::Solrizer.pointyize_add(e)
puts s

__END__
{
  "name": "i-f09a939b",
  "json_class": "Chef::Node",
  "automatic": {
    "domain": "opscode.us",
    "os": "linux",
    "virtualization": {
      "role": "guest",
      "emulator": "xen"
    },
    "hostname": "lb-prod-i-f09a939b",
    "platform": "ubuntu"
  },
  "normal": {
    "apache": {
      "user": "www-data",
      "keepalive": "On"
    }
  },
  "chef_type": "node",
  "default": {
    "ha_role": "secondary",
    "opscode_lb_heartbeat": {
      "heartbeatsecret": "WIaVjtQurY0Q7sti"
    },
    "red_zookeeper_mp": {
      "role": "zookeeper_mp"
    },
    "app_environment": "production"
  },
  "override": {
    "filesystem": {},
    "opscode_lb_type": "external",
    "rabbitmq": {
      "users": {
        "chef": "Tat9THLuiOkdtyyH5VVf"
      }
    }
  },
  "run_list": [
    "role[production]",
    "role[ha-secondary]",
    "recipe[aws]"
  ],
  "_rev": "147-bb4f74122079d1feac675c1b2c57bfcc"
}