Feature request: selectable IP attribute

[jhmartin]

AWS cloud hosts have a public and private address. The private address is node['ipaddress'] but the public address is elsewhere. The feature is to allow searches to be configured to use an arbitrary alternate attribute to fetch the IP address, or at least the 'public' address.

So in the default recipe:

              if node.attribute?('cloud') && (member['cloud']['provider'] == node['cloud']['provider'])
                member['cloud']['local_ipv4']
              else
                member['cloud']['public_ipv4']
              end

This logic should let me override the default and choose public_ipv4.