Feature request: export service/version information about fastly-exporter

[peterbourgon]

I'm not against it, but it's not obvious to me how this would be encoded in Prometheus metrics. If someone has a good suggestion there, I can certainly take a shot at an implementation.

[wosc]

I guess the "Grafana annotations" part will need some additional jury-rigging ;), for the time being I'm mostly concerned with getting the information out of the API in the first place. Luckily, the version is a plain integer, so what do you think about something like this:

fastly_service_version{service_id="ABCxyz",service_name="www.example.com"} 123.0
fastly_service_version{service_id="DEFtuv",service_name="img.example.com"} 42.0

[peterbourgon]

Generally it's a mistake to report data like that in the actual value, rather prefer to put everything in labels and allow the value to be constant 1.

[wosc]

Oh. What are the risks/downsides? I have not been using Prometheus for all that long, so I guess I haven't painted myself into that particular corner yet (since I don't see anything wrong with the approach ;).

But to be honest I'm not very particular about the format -- all I want is to be able to retrieve a set of "sevice x has version y" items, which should be easy either way. (And possibly query "which version does service x have".) Thanks!

[peterbourgon]

@wosc Are you able to easily build and test the version in the branch associated with #30? If yes, please give it a shot and make sure it meets your requirements. If no, let me know and I'll cut a release for you.

[wosc]

Thanks to your Dockerfile building was very easy! (I did have to manually clone peterbourgon/usage to vendor/ first, probably because I know nothing about the golang build toolchain yet ;).

The resulting metrics look fine to me, they give me the currently active version, which is exactly what I wanted. Thank you so much for building it! :)

fastly_rt_service_info{service_id="...",service_name="[PROD] www.zeit.de",service_version="152"} 1
fastly_rt_service_info{service_id="...",service_name="[PROD] img.zeit.de",service_version="65"} 1