Dashboard dummy metrics generation

dev.exs

def metrics do
  [
    distribution("a.b.c",
      tags: [:foo],
      unit: {:native, :millisecond}
    ),
    distribution("a.b.c",
      tags: [:foo, :bar],
      unit: {:native, :millisecond}
    ),
    distribution("a.b.c",
      unit: {:native, :millisecond}
    ),
    # Phoenix Metrics
    # ...
  ]
end

dummy_metrics.exs

defmodule Dummy do
  @labels ~w[foo bar baz qux bim bom someversysuperultralargepagepath/with/subpaths nairobi mediteranean_sea]
          |> List.to_tuple()

  def metric_value do
    value = :rand.uniform(125_000_000)

    case :rand.uniform(2) do
      1 -> value
      2 -> -value
    end
  end

  def tag_value do
    length = tuple_size(@labels)
    idx = :rand.uniform(length) - 1
    elem(@labels, idx)
  end

  def execute do
    for _i <- 1..200 do
      :telemetry.execute(
        [:a, :b],
        %{c: metric_value(), d: metric_value()},
        %{foo: tag_value(), bar: tag_value()}
      )
    end
  end
end