How to configure the Plug.Static without Phoenix

Question

I am trying to figure out how to configure Plug.Static without any other framework (Phoenix, Sugar, etc); just Cowboy, Plug and Elixir. I just don\'t know how t

Answer 1

This is the answer I was looking for.

In the application start method use the Plug.Router with Cowboy:

defmodule HttpServer.Application do
  require Logger
  use Application

  def start(_type, _args) do
    children = [
      {Plug.Adapters.Cowboy2, scheme: :http, plug: HttpServer.Router, options: [port: 4002]}
    ]

    opts = [strategy: :one_for_one, name: HttpServer.Supervisor]

    Supervisor.start_link(children, opts)
  end
end

The router module looks like this:

defmodule HttpServer.Router do
  use Plug.Router

  plug(Plug.Logger)
  plug(:redirect_index)
  plug(:match)
  plug(:dispatch)

  forward("/static", to: HttpServer.StaticResources)

  get "/sse" do
    # some other stuff...
    conn
  end

  match _ do
    send_resp(conn, 404, "not found")
  end

  def redirect_index(%Plug.Conn{path_info: path} = conn, _opts) do
    case path do
      [] ->
        %{conn | path_info: ["static", "index.html"]}

      ["favicon.ico"] ->
        %{conn | path_info: ["static", "favicon.ico"]}

      _ ->
        conn
    end
  end
end

Here requests to "/static" are forwarded to the HttpServer.StaticResources module, but first, the request path is modified for "/" and "/favicon.ico" with plug(:redirect_index). All static files (*.html, *.ico, *.css, *.js etc.) are placed in the default location (project_dir/priv/static).

Finally, the StaticResource module:

defmodule HttpServer.StaticResources do
  use Plug.Builder

  plug(
    Plug.Static,
    at: "/",
    from: :http_server
  )

  plug(:not_found)

  def not_found(conn, _) do
    send_resp(conn, 404, "static resource not found")
  end
end