Exports Monitorex metrics in Prometheus text format (plain text, no deps).

Reads directly from ETS tables — no locks, no side effects. Designed for scraping by Prometheus or the Datadog agent.

Usage

iex> Monitorex.PrometheusExporter.format()
"# HELP monitorex_requests_total ..."

The output is a string in Prometheus exposition format: https://prometheus.io/docs/instrumenting/exposition_formats/