Add node metrics with exporter

[fracek]

When running the node in production I'm interested in monitoring the overall node's health. It would be sweet to have the node collect several metrics and export them to InfluxDB and/or Prometheus. Go Ethereum offers this feature and I think it's a good reference.

[Mirko-von-Leipzig]

What sort of metrics do you have in mind?

[Mirko-von-Leipzig]

Geth metrics: https://geth.ethereum.org/docs/interface/metrics

[Mirko-von-Leipzig]

This is something that has been requested a few times now, and its definitely something we want to support.

That said, it will be a medium term objective and not the short term priority.

[fracek]

Sorry for the late reply, for some reasons I didn't see the previous response. What geth does is good enough, even better would be using a standard like opentelemetry for instrumentation and tracing.

[Mirko-von-Leipzig]

Thanks -- will have a look into the standards.

[fracek]

Are you open to external contributions for this? I'm running pathfinder in production and I need this and #194. I can write a more thorough proposal before I start working on this so that we can agree on how it will work.

[Mirko-von-Leipzig]

We would really appreciate a contribution here -- our bandwidth is currently quite limited.

I can write a more thorough proposal before I start working on this so that we can agree on how it will work.

I think this is a great starting point!

And additional note - we will be unavailable next week (16-20 May), so communication will be sparse then.

[CHr15F0x]

Since #545 and #620 we've got prometheus metrics support as described in the readme file. @fracek are these sufficient for you?

[CHr15F0x]

Sorry, I was about to just comment, not closing yet.

[fracek]

Yep, looks good to me. Thank you!