Exports Prometheus metrics via configurable endpoint:

# define plug
defmodule MetricsPlugExporter do
  use Prometheus.PlugExporter
end

# on app startup (e.g. supervisor setup)
MetricsPlugExporter.setup()

# in your plugs pipeline
plug MetricsPlugExporter

Do not add to Phoenix Router pipelines! You will be getting 404!

Note that router pipelines are only invoked after a route is found.
No plug is invoked in case no matches were found.

Metrics

Also maintains telemetry metrics:

• telemetry_scrape_duration_seconds
• telemetry_scrape_size_bytes

Do not forget to call setup/0 before using plug, for example on application start!

Configuration

Plugs exporter can be configured via PlugsExporter key of :prometheus app env.

Default configuration:

config :prometheus, MetricsPlugExporter, # (you should replace this with the name of your plug)
  path: "/metrics",
  format: :auto, ## or :protobuf, or :text
  registry: :default,
  auth: false

Export endpoint can be optionally secured using HTTP Basic Authentication:

  auth: {:basic, "username", "password"}