feat(metrics): add push gateway support for Prometheus metrics

[mablr]

Closes #19229

This spawns a task to push metrics to prometheus following configurable interval (default 5sec).
Added CLI flags for push gateway url and push interval.

[mablr]

I tested it locally like this :

docker run -d -p 9091:9091 prom/pushgateway

reth node --metrics=0.0.0.0:9001 --metrics.push.url=http://localhost:9091/metrics/job/test

curl http://localhost:9091/metrics

It seems to push correctly.

I'm wondering if it's relevant to add a test that spawns a HTTP server in order to inspect the PUT requests sent by the MetricServer. Wdyt ?

[shekhirin]

only two comments, this is basically what we need, yeah!

[mattsse]

this lgtm

@Rjected likely has more context here

[Rjected]

This should work, although I think it would be good to figure out how to add config options to how we currently build our PrometheusRecorder, so we can use the builtin push-gateway support:
https://docs.rs/metrics-exporter-prometheus/latest/metrics_exporter_prometheus/struct.PrometheusBuilder.html#method.with_push_gateway

If we were to implement auth then I would prefer using the builtin support as well

[mablr]

so we can use the builtin push-gateway support: https://docs.rs/metrics-exporter-prometheus/latest/metrics_exporter_prometheus/struct.PrometheusBuilder.html#method.with_push_gateway
If we were to implement auth then I would prefer using the builtin support as well

While implementing it, I've seen also that there is http_listener, but I followed the existing http listener pattern for the push gateway.

I would be happy to give a follow up to this very soon 👍