added /prometheus as a Spring Boot Endpoint

[eliezio]

fixed doc issues

[brian-brazil]

Thanks!

[fiunchinho]

When will this be released? Thanks!

[brian-brazil]

Next week sometime is the plan.

[fiunchinho]

I was trying to test it locally just copy and pasting the files from this pull request, but I can't get it to work properly. After adding the @EnablePrometheusEndpoint() annotation to my Application, I can visit the /prometheus endpoint but with empty result.
The /metrics endpoint is returning the usual response.

Do I need to do anything else?

[eliezio]

The metrics you are seeing through the /metrics endpoint are those that were auto-configured by Spring Boot.
To see these metrics also through /prometheus endpoint, you need to instantiate a SpringBootMetricsCollector bean as stated on its documentation (see https://prometheus.io/client_java/io/prometheus/client/spring/boot/SpringBootMetricsCollector.html).
Maybe there should be a second annotation (i.e.: @ExportPublicMetricsToPrometheus) to simplify this task.

[fiunchinho]

You are right. It works now, thank you very much