Peep.Plug (peep v4.2.0)

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Use this plug to expose your metrics on an endpoint for scraping. This is useful if you are using Prometheus.

This plug accepts the following options:

  • :peep_worker - The name of the Peep worker to use. This is required.

  • :path - The path to expose the metrics on. Defaults to "/metrics".

  • :on_unmatched_path - The intended behavior of this plug when handling a request to a different path. There are two possible values:

    • :continue (default) - This allows for subsequent Plugs in a router to be executed. This option is useful when Peep.Plug is part of a router for a Phoenix application, or a router that matches other paths after Peep.Plug.

    • :halt - Responds to requests with 404. This option is useful when Peep.Plug is used for serving metrics on a separate port, which is a practice that is encouraged by other libraries that export Prometheus metrics.

Usage

You can use this plug in your Phoenix endpoint like this:

  plug Peep.Plug, peep_worker: :my_peep_worker

Or if you'd rather use a different path:

  plug Peep.Plug, path: "/my-metrics"

If you are not using Phoenix, you can use it directly with Cowboy by adding this to your applications's supervision tree:

  {Plug.Cowboy, scheme: :http, plug: Peep.Plug, options: [port: 9000]}

Similarly, if you are using Bandit, you can use it like so:

  {Bandit, [
    scheme: :http,
    plug: {Peep.Plug, peep_worker: :my_app},
    port: 9000
  ]}