I configure Plug.Static to:

  plug Plug.Static,
    at: "/admin",

and point the assets to it:

<link phx-track-static rel="stylesheet" href={~p"/admin/assets/app.css"} />

This serves the web page correctly, but I am warned against it:

warning: no route path for MyWeb.Router matches "/admin/assets/app.css"
  lib/my_web/components/layouts/root.html.heex:10: MyWeb.Layouts.root/1

CI won’t let warnings through, so..

Attempt 1

I tried working with the endpoint :static_url config, but could not figure out a way to make this config help. In fact, I’m not sure how this would be used now that we have verified routes? Is this route helper specific?

config :my_web, MyWeb.Endpoint
  static_url: [path: "/admin"]

Attempt 2

I reset the at: to root

plug Plug.Static,
  at: "/",

and changed static_paths/0 to hold the prefix

def static_paths, do: ~w(assets fonts images favicon.ico robots.txt) |> Enum.map(&Path.join("admin", &1))

but this returned 404s for app.css

Workable Solution

I was able to solve the warnings with the below

use Phoenix.VerifiedRoutes,
  endpoint: MyWeb.Endpoint,
  router: MyWeb.Router,
  statics: Enum.map(MyWeb.static_paths(), &Path.join("admin", &1))

but it didn’t quite feel ideal. I’m wondering if there’s something more direct that I’m missing.