[booop]

The tool doesn't look like it's meant to be run within a cloud. Instances in a VPC without internet access would have only private IP addresses within the CIDR range of the subnet in which they are launched.

It's to find out which cloud a public IP address belongs to, for which the public data source/whois lookup seems the only option.

PS: the metadata (in case of AWS) can be accessed only within the instance itself.