Support for Prometheus

[gaby]

@erikdubbelboer I notice multiple Prometheus solutions for fasthttp are just using the fasthttp adaptor to handle calling the prometheus net/http handler.

I did some googling at there was an issue opened in the Prometheus Golang Client back in 2017. Basically the promhttp will have to be converted to promfasthttp to allow fasthttp have native prometheus.

Someone created a draft of this back in 2017 but it's way out of date. That draft can be found here: krisdioles/client_golang@20b36c8

The current promhttp can be found here (this one would need to be converted to fasthttp): https://github.com/prometheus/client_golang/blob/main/prometheus/promhttp/http.go

I reached out to the Prometheus dev but they suggested this should be handle in this repo or in the prometheus-community as a new module or I can host a module if that also helps get this done.

Discussion here: prometheus/client_golang#356

I figured posting here and asking you if this is something the fasthttp team can do to integrate Prometheus metrics into fasthttp. This will greatly enhance the fasthttp ecosystem as a whole.

[erikdubbelboer]

I'm afraid I don't have time to do that. But a pull request is of course always welcome!