code: def find_instance_and_eni_by_ip(vpc_info, ip):
      
      for instance in vpc_info['instances']:
          for eni in instance.interfaces:
              for pa in eni.private_ip_addresses:
                  if pa.private_ip_address == ip:
                      return instance, eni
      raise VpcRouteSetError("Could not find instance/eni for '%s' "
                             "in VPC '%s'." % (ip, vpc_info['vpc'].id))
docs: Given a specific IP address, find the EC2 instance and ENI.
  
      We need this information for setting the route.
  
      Returns instance and emi in a tuple.