ezcontainer_example/lib/ezcontainer_railway_web/plugs/railway_check.ex

defmodule EzcontainerRailwayWeb.RailwayCheck do
  alias EzcontainerRailway.Projects
  alias EzcontainerRailway.Railway
  alias Phoenix.Controller
  import Plug.Conn

  def init(default), do: default

  def call(conn, _opts) do
    case get_session(conn, :railway_token) do
      nil -> 
        conn
        |> Controller.put_flash(:error, "You need a railway token")
        |> Controller.redirect(to: "/")
      token ->
        p =
          case Projects.get_project_by_token(token) do
            nil -> Projects.create_project(token)
            p -> p
          end

        conn
        |> put_session(:project_id, p.id)
    end
  end
end