Hands-On Software Engineering with Golang

Exporting metrics for scraping

After registering our metrics with Prometheus and instrumenting our code to update them where needed, the only additional thing that we need to do is expose the collected values over HTTP so that Prometheus can scrape them.

The promhttp subpackage from the Prometheus client package provides a convenience helper function called Handler that returns an http.Handler instance that encapsulates all the required logic for exporting collected metrics in the format expected by Prometheus.

The exported data will not only include the metrics that have been registered by the developer but it will also contain an extensive list of metrics that pertain to the Go runtime. Some examples of such metrics are as follows:

• The ...