fastly_rt_service_info for group_left/group_right metadata about fastly-exporter

[peterbourgon]

No objection, modulo the implementation. I suspect this should be very minimal changes.

[peterbourgon]

So we now have service_info with labels service_id, service_name, and service_version. In theory we could labels there for anything returned by /service, but I want to be judicious. Is customer_id really valuable in this context? Are there other fields that have clear and obvious value?

For datacenter, domain, and customer, I think it's a little less clear. These are meta-properties of your configuration or even Fastly itself, and maybe not directly related to individual services. I'm open to adding additional stuff like that, but I'd like to understand the use cases that information would enable. Do you have any? :)

[peterbourgon]

#80 adds the datacenter_info metric and establishes a pattern for arbitrary metadata. This issue is a bit general, so I'm gonna go ahead and close it — please open new issues for any additional metadata you'd like to see.