prometheus default metrics (go_goroutines, go_info, go_memstats ...) are not exposed

[xmlking]

prometheus exporter is not exposing default metrics (go_goroutines, go_info, go_memstats ...)

The workaround to fix is with ugly code below

var pConfig = prometheus.Config{Registry: goprom.DefaultRegisterer.(*goprom.Registry)}
exporter, err := prometheus.New(pConfig, pController)

please consider changed this code to

	if config.Registry == nil {
		config.Registry = prometheus.DefaultRegisterer.(*prometheus.Registry)}
	}

My Workaround
https://github.com/xmlking/toolkit/blob/develop/telemetry/metrics/metrics.go#L64

[jmacd]

The OTel library has a module for runtime metrics, https://github.com/open-telemetry/opentelemetry-go-contrib/tree/main/instrumentation/runtime

[dashpole]

I believe this is addressed with the current (new) version of the prometheus exporter. See #3239 (comment).

Basically, we register with the DefaultRegisterer by default, and allow users to override this with the WithRegisterer option.

[MrAlias]

I believe this is addressed with the current (new) version of the prometheus exporter. See #3239 (comment).

Basically, we register with the DefaultRegisterer by default, and allow users to override this with the WithRegisterer option.