Custom metrics wrapper example

[Krever]

Lets provide and example on how to build custom metrics reporter. It seems quite a common case.

It should allow measuring execution time of given endpoint. Its especially usable for akka http, because once directive is built there is no way to extract endpoint matching path(in many cases we want to log metrics with label such as "/my/endpoint/:id" instead of "/my/endpoint/12345").

Maybe we can make something generic and ready to use out-of-the-box but an example would be enough.

[Fristi]

Have been thinking also about this.

Codahale seems like a metrics reporter library people commonly use. I would do some research however if this is covering most of the cases. If so, maybe we can create a Codehale metrics interpreter which can be composed together with client and server interpreters?

The user can decide wether to export this to Promotheus or something else via an endpoint.