prepare router to serve single page web app

lib/myapp/application.ex

@@ -14,6 +14,9 @@ defmodule MyApp.Application do
       supervisor(MyAppWeb.Endpoint, []),
       # Start your own worker by calling: MyApp.Worker.start_link(arg1, arg2, arg3)
       # worker(MyApp.Worker, [arg1, arg2, arg3]),
+
+      # start cachex for key/value store
+      worker(Cachex, [:myapp, []])
     ]
 
     # See https://hexdocs.pm/elixir/Supervisor.html

lib/myapp_web/controllers/page_controller.ex

@@ -0,0 +1,22 @@
+defmodule MyAppWeb.PageController do
+  use MyAppWeb, :controller
+
+  # serve index.html - cache the file after reading it to minimize IO
+  @spec index(map, map) :: any
+  def index(conn, _params) do
+
+    file = Cachex.get(:myapp, "index.html")
+    |> get_file
+
+    conn
+    |> html(file)
+  end
+
+  defp get_file({:ok, data}), do: data
+  defp get_file({:missing, _}) do
+    file = File.read!("./priv/static/index.html")
+    Cachex.set(:myapp, "index.html", file)
+    file
+  end
+  
+end

lib/myapp_web/endpoint.ex

@@ -8,8 +8,9 @@ defmodule MyAppWeb.Endpoint do
   # You should set gzip to true if you are running phoenix.digest
   # when deploying your static files in production.
   plug Plug.Static,
-    at: "/", from: :myapp, gzip: false,
-    only: ~w(css fonts images js favicon.ico robots.txt)
+    at: "/", from: :myapp, gzip: true
+    # serve everything in the static folder
+    # only: ~w(css *.css fonts images js favicon.ico robots.txt)
 
   # Code reloading can be explicitly enabled under the
   # :code_reloader configuration of your endpoint.

lib/myapp_web/router.ex

@@ -54,4 +54,9 @@ defmodule MyAppWeb.Router do
     end
   end
   
+  # catch all for serving single page web app
+  scope "/*all", MyAppWeb do
+    get "/", PageController, :index
+  end
+
 end