Add carbon.txt lookup endpoint

[fershad]

Is your feature request related to a problem? Please describe.
Add the ability for users to provide a single domain and check for a carbon.txt file present for that domain.

Describe the solution you'd like
This would be similar to the hosting.check() functionality, however would not (currently) permit multiple domains to be checked at once (by using an array). This would use the https://carbon-txt-api.greenweb.org/api/validate/domain/ endpoint.

Describe alternatives you've considered
Users can use a fetch request to lookup a domain using the endpoint above. This does not require CO2.js. The purpose to building this into CO2.js is to make it a bit easier.

[Ryuno-Ki]

Would be cool, if this would end up under a .well-known/carbon.txt :)

[fershad]

A carbon.txt file can be placed at that path, and our validator does check for that if nothing is found at the root. We've covered that off in some FAQs on this page: https://carbontxt.org/faq

For simplicity, given a lot of the time we're not talking with web admin folks within organisations, we've opted to guide people towards putting the file at the root of their domain, as they would a robots.txt.

There's been some discussion here about that as well: thegreenwebfoundation/carbon-txt-site#9

[fershad]

@timcowlishaw I'm starting to build this out now, but noticing I get errors when trying to run lookups in the NodeJS environments. I think it's down to accept origins settings for the validator endpoint.

https://github.com/thegreenwebfoundation/carbon-txt-validator/blob/7426c80ac70b2bce37057ec9842a4c33a5a94d8e/src/carbon_txt/web/config/settings/production.py#L4

Something for us to discuss in our tech call on Tuesday 🙏🏼

[fershad]

I’ve got working examples from in the browser hitting the carbon.txt validator endpoint with CO2.js.

CodePen: CO2.js 🤝🏼 Carbon.txt

Observable: https://observablehq.com/d/55ee768bb40c1f4b

So looks like CORS won’t be an issue.