prom_ex VS elixir_prom_ex_example

This post is about another cool Fly.io feature --- built-in Prometheus metrics --- and how easy it is to take advantage of them in an Elixir application. I wrote and maintain an Elixir library, PromEx, that makes it a snap to export all sorts of metrics from your Elixir applications and get them on dashboards in Grafana. Let's explore some of the concepts surrounding Prometheus and see how we can leverage the Fly.io monitoring tools in an Elixir application to get slick looking dashboards like this one:

Managing, configuring and administering your own Prometheus instance can be a bit of a tall order if you have never worked with Prometheus before. Fortunately, all you need to do to enable Prometheus metrics for your application is add a couple of lines to your fly.toml manifest file. All Fly.io needs to know is what port and path your metrics will be available at. For the TODO List Elixir application for example, the following configuration was all that was needed: