Create a public api for telemetry data

[mariopino]

Hi, I think that would be nice to have a public api to retrieve the telemetry data displayed at https://telemetry.polkadot.io.

[woss]

this version doesn't use the DB, means that no data is stored at all.
Not sure will be supported or not but for now, there isn't a way to do it (as far as i know).
I'm thinking that saving to the DB would be under GDPR or something similar

[maciejhirsz]

The backend does store current state of all chains and nodes connected in memory, so API is doable, it just wouldn't have access to any history.

[chevdor]

I would expose a Prometheus endpoint fed with the live data.
It is then up to the users to use and react only on the live data or archive data into some InfluxDB for instance.

[CodeSandwich]

Adding support for Prometheus would be a perfect completion for the node's monitoring. The data could be then funneled into a single analysis/visualization solution like Grafana.

We're trying to observe the state of the whole network. We have a few nodes tightly monitored with Prometheus, but we're lacking the general view of the whole network. We can analyze with our eyes the current state on telemetry.polkadot.io, but that's not enough, we need automation and historical data. This would solve our problem.