metrics: enable exporting metrics for aggregation

[shoenig]

It would be nice to have a way to track metrics around DNS queries and whether they were blocked, and if so, in what manner (default vs. custom list).

Not sure if we should pick one metrics format, need to look into what's common these days (e.g. prometheus vs. statsd, etc.)

[0rax]

Just stumbled onto your plugin, it looks really interesting and I was wondering if there was any metrics exposed by it.

Just my twp cents: it looks like, for CoreDNS at least, the most logical thing to do would be to implement them as Prometheus metrics. This way they would be available directly when using the metrics plugin. It really seems that most other "built-in" plugin relies on it to serve statistics about what they do.

If we take the forward plugin as an example, they do exposes them here and increment them here.

I might take a look at doing a quick implementation of it in your plugin if I get some time to pour into it.

[shoenig]

Hi @0rax! Following the forward plugin as an example sounds good to me.

It certainly would be nice to finally have metrics coming out of this thing 🙂