I thought it worked but in fact that does not work because at compile time
Application.get_env(:my_app, :downs_path) || Path.expand(’./downs’),
Application.get_env returns nil so you get the path of the machine which builds the release not the runtime path
I ended up with
plug Plug.Static, at: “/downs”, from: {:vf, “../../../downs”},
that is a relative path which saves the need for the ENV var
