code: def get_external_host_tags(self):
          
          self.log.debug("Collecting external_host_tags now")
          external_host_tags = []
          for k, v in iteritems(self.external_host_tags):
              external_host_tags.append((k, {SOURCE_TYPE: v}))
  
          self.log.debug("Sending external_host_tags: %s", external_host_tags)
          return external_host_tags
docs: Returns a list of tags for every guest server that is detected by the OpenStack
          integration.
          List of pairs (hostname, list_of_tags)