Using Prometheus Exporters

In this chapter, we have configured application metrics to provide data for Prometheus to scrape and collect, so why do we need to worry about exporters? As you have seen, Docker and cAdvisor have nicely exposed data endpoints from which Prometheus can gather metrics. But these have limited functionality. As we have seen from our new web-nginx site, there is no relevant data exposed by the web page running on our image. We can use exporters to help gather metrics from the application or service, and then provide data in a way that Prometheus can understand and gather.

Although this may seem to be a major flaw in how Prometheus works, due to the increase in the use of Prometheus and the fact that it is open-source, vendors and third-party providers are now providing exporters to help you get your metrics from the application.

This means that, by installing a specific library or using a prebuilt Docker image to run your application, you can expose your...