RFC: `riemann-domain-check` to monitor domain name expiration date

[smortex]

Issue

We currently have no tooling to check if a domain name is about to expire. While whois(1) is ubiquitous to query information about a domain, the format is not standardized and parsing the output is tedious. But good news everyone, Registration Data Access Protocol (RDAP) will (maybe) change that!

This seems a quite trivial tool to build: there is a rdap gem available, and the riemann-domain-check tool could accept a list of domains to check, a warning and a critical thresholds in day (e.g. 30, 7) and output metrics like:

service: example.com expiration date
metric: 1668968347
state: warning
description: Domain expire in 30 days

Should riemann-domain-check be part of riemann-tools or should it be a side project?

What's your riemann-tools version?

n/a

What platform are you on?

n/a