analytics/lib/plausible_web/auth_plug.ex

defmodule PlausibleWeb.AuthPlug do
  import Plug.Conn
  use Plausible.Repo

  def init(options) do
    options
  end

  def call(conn, _opts) do
    case get_session(conn, :current_user_id) do
      nil -> conn
      id ->
        user = Repo.get_by(Plausible.Auth.User, id: id)
               |> Repo.preload(:subscription)
        if user do
          assign(conn, :current_user, user)
        else
          conn
        end
    end
  end
end