Gives limited tracing around absinthe calls. Shamelessly adapted from the Phoenix plug in new_relic.ex

new_relic_plug_absinthe.ex

defmodule NewRelic.Plug.Absinthe do
  @moduledoc """
  A plug that instruments Phoenix controllers and records their response times in New Relic.

  Inside an instrumented controller's actions, `conn` can be used for further instrumentation with
  `NewRelic.Plug.Instrumentation` and `NewRelic.Plug.Repo`.

  ```
  defmodule MyApp.UsersController do
    use Phoenix.Controller
    plug NewRelic.Plug.Phoenix

    def index(conn, _params) do
      # `conn` is setup for instrumentation
    end
  end
  ```
  """

  @behaviour Elixir.Plug
  import Elixir.Plug.Conn

  def init(opts) do
    opts
  end

  def call(conn, _config) do
    if NewRelic.configured? do
      transaction_name = conn.params
      |> Map.get("operationName")

      # TODO: Figure out how to add parameter info to a transaction
      # variables = conn.body_params
      # |> Map.get("variables")
      # |> IO.inspect

      conn
      # |> IO.inspect
      |> put_private(:new_relixir_transaction, NewRelic.Transaction.start(transaction_name))
      |> register_before_send(fn conn ->
        NewRelic.Transaction.finish(Map.get(conn.private, :new_relixir_transaction))

        conn
      end)
    else
      conn
    end
  end
end

router.ex

  pipeline :graphql do
    plug Guardian.Plug.VerifyHeader
      plug Guardian.Plug.EnsureAuthenticated, handler: Guardian.Plug.ErrorHandler
      plug Guardian.Plug.LoadResource
      plug NewRelic.Plug.Absinthe
      plug GraphQLPlug
  end