Show HN: Which-cloud, what cloud does an ip address belong to? | Hacker News Reader

Show HN: Which-cloud, what cloud does an ip address belong to?

github.com

38 pointsBenjaminCoe9 comments

This code seems to rely on IP ranges and whois lookups, which won't work if you're running on a network / VPC that has no internet access

Some clouds provide a metadata api accessible via a link-local address. These are accessibly regardless of what network your instance is in.

AWS Metadata API: http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-insta...

GCE Metadata API: https://cloud.google.com/compute/docs/metadata

Azure Metadata API: https://azure.microsoft.com/en-us/blog/what-just-happened-to...

This library only appears to support detecting AWS/GCE/Azure, so perhaps trying URLs in each metadata API with no / minimal timeout is a more robust way of accomplishing this instead of relying on whois, and could provide the same functionality as is currently supported in the library.

The downside of this approach is that maybe some clouds/VPS's don't have metadata APIs accessible in this manner. Maybe this doesn't work for some more obscure services, if you want to be super comprehensive.

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.

what does this add instead of using whois?

AWS (http://docs.aws.amazon.com/general/latest/gr/aws-ip-ranges.h...), GCE (https://cloud.google.com/compute/docs/faq#where_can_i_find_s...), and other clouds maintain an up-to-date list of the ip blocks within their data-centers -- providing for more accurate data than a whois lookup.

however! I just added whois as a fallback, this seems like a really good idea:

https://github.com/bcoe/which-cloud/pull/10

What are you doing to prevent others using you as a whois proxy?

Alternately, how are you planning to evade the (rather restrictive) rate limits which whois servers impose?

it's a goal to use the advertised IP blocks of cloud providers where possible, with whois simply as a fallback.

Will happily accept patches for other providers.

You realize that the majority of IPs submitted may not be from a known cloud provider/test suite, and so you're still dealing with the rate limiting from falling back for most requests?

I built this library to track signups for an application that has a fairly low request rate.

if you need a higher request rate 🤷 ¯\_(ツ)_/¯ pitch in and help add support for a wider variety of cloud providers.

See also: The Hurricane Electric BGP Toolkit shows the ISP based on the AS number from which the IP address is announced: http://bgp.he.net/

Example: http://bgp.he.net/ip/104.196.27.39

Reply on news.ycombinator.com