Instrumentation

[ghost]

It'd be super useful to expose a few basic metrics, like number of peers and requests answered, if there is such a thing.

In go-ipfs we're exposing an endpoint for Prometheus at http://localhost:5001/debug/metrics/prometheus, and grepping for ipfs_ you can see a few metrics.

There's a JS client in https://github.com/siimon/prom-client -- the peers count would be a gauge, the requests count a counter, etc.

[ghost]

This would probably best be exposed within an additional http listener on a separate configurable address

[daviddias]

=> #114