Complete authentication flow with dummy password

lib/music_library_web/plug/require_login.ex

@@ -0,0 +1,21 @@
+defmodule MusicLibraryWeb.Plug.RequireLogin do
+  @behaviour Plug
+
+  import Plug.Conn
+  import Phoenix.Controller, only: [put_flash: 3, redirect: 2]
+
+  @impl true
+  def init(opts), do: opts
+
+  @impl true
+  def call(conn, _opts) do
+    if get_session(conn, :logged_in) do
+      conn
+    else
+      conn
+      |> put_flash(:error, "You must be logged in to access this page")
+      |> redirect(to: "/login")
+      |> halt()
+    end
+  end
+end