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,
+    at: "/", from: :myapp, gzip: true
-    only: ~w(css fonts images js favicon.ico robots.txt)
+    # 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

mix.exs

@@ -46,6 +46,7 @@ defmodule MyApp.Mixfile do
       {:httpoison, "~> 0.13"},
       {:dialyxir, "~> 0.5", only: [:dev], runtime: false},
       {:ex_guard, "~> 1.3", only: :dev},
+      {:cachex, "~> 2.1"},
     ]
   end
 

mix.lock

@@ -1,5 +1,6 @@
 %{"argon2_elixir": {:hex, :argon2_elixir, "1.2.14", "0fc4bfbc1b7e459954987d3d2f3836befd72d63f3a355e3978f5005dd6e80816", [], [{:elixir_make, "~> 0.4", [hex: :elixir_make, repo: "hexpm", optional: false]}], "hexpm"},
   "base64url": {:hex, :base64url, "0.0.1", "36a90125f5948e3afd7be97662a1504b934dd5dac78451ca6e9abf85a10286be", [], [], "hexpm"},
+  "cachex": {:hex, :cachex, "2.1.0", "fad49b4e78d11c6c314e75bd8c9408f5b78cb065c047442798caed10803ee3be", [], [{:eternal, "~> 1.1", [hex: :eternal, repo: "hexpm", optional: false]}], "hexpm"},
   "certifi": {:hex, :certifi, "2.0.0", "a0c0e475107135f76b8c1d5bc7efb33cd3815cb3cf3dea7aefdd174dabead064", [], [], "hexpm"},
   "comeonin": {:hex, :comeonin, "4.0.3", "4e257dcb748ed1ca2651b7ba24fdbd1bd24efd12482accf8079141e3fda23a10", [], [{:argon2_elixir, "~> 1.2", [hex: :argon2_elixir, repo: "hexpm", optional: true]}, {:bcrypt_elixir, "~> 0.12.1 or ~> 1.0", [hex: :bcrypt_elixir, repo: "hexpm", optional: true]}, {:pbkdf2_elixir, "~> 0.12", [hex: :pbkdf2_elixir, repo: "hexpm", optional: true]}], "hexpm"},
   "connection": {:hex, :connection, "1.0.4", "a1cae72211f0eef17705aaededacac3eb30e6625b04a6117c1b2db6ace7d5976", [], [], "hexpm"},
@@ -10,6 +11,7 @@
   "dialyxir": {:hex, :dialyxir, "0.5.1", "b331b091720fd93e878137add264bac4f644e1ddae07a70bf7062c7862c4b952", [], [], "hexpm"},
   "ecto": {:hex, :ecto, "2.2.7", "2074106ff4a5cd9cb2b54b12ca087c4b659ddb3f6b50be4562883c1d763fb031", [], [{:db_connection, "~> 1.1", [hex: :db_connection, repo: "hexpm", optional: true]}, {:decimal, "~> 1.2", [hex: :decimal, repo: "hexpm", optional: false]}, {:mariaex, "~> 0.8.0", [hex: :mariaex, repo: "hexpm", optional: true]}, {:poison, "~> 2.2 or ~> 3.0", [hex: :poison, repo: "hexpm", optional: true]}, {:poolboy, "~> 1.5", [hex: :poolboy, repo: "hexpm", optional: false]}, {:postgrex, "~> 0.13.0", [hex: :postgrex, repo: "hexpm", optional: true]}, {:sbroker, "~> 1.0", [hex: :sbroker, repo: "hexpm", optional: true]}], "hexpm"},
   "elixir_make": {:hex, :elixir_make, "0.4.0", "992f38fabe705bb45821a728f20914c554b276838433349d4f2341f7a687cddf", [], [], "hexpm"},
+  "eternal": {:hex, :eternal, "1.2.0", "e2a6b6ce3b8c248f7dc31451aefca57e3bdf0e48d73ae5043229380a67614c41", [], [], "hexpm"},
   "ex_guard": {:hex, :ex_guard, "1.3.0", "0f5c50b90a7e4c599b45d02448ae53eabffc33adb7bfdfc5f5507715e7662a25", [], [{:fs, "~> 0.9", [hex: :fs, repo: "hexpm", optional: false]}], "hexpm"},
   "fs": {:hex, :fs, "0.9.2", "ed17036c26c3f70ac49781ed9220a50c36775c6ca2cf8182d123b6566e49ec59", [], [], "hexpm"},
   "gettext": {:hex, :gettext, "0.14.0", "1a019a2e51d5ad3d126efe166dcdf6563768e5d06c32a99ad2281a1fa94b4c72", [], [], "hexpm"},

priv/static/index.html

@@ -0,0 +1,5 @@
+<html>
+  <body>
+    Test 123
+  </body>
+</html>

test/myapp_web/controllers/page_controller_test.exs

@@ -0,0 +1,11 @@
+defmodule MyAppWeb.PageControllerTest do
+  use MyAppWeb.ConnCase, async: true
+
+  test "index.html should be cached" do
+    assert Cachex.get(:myapp, "index.html") == {:missing, nil}
+    conn = build_conn() |> get("/lsakdjfl")
+    {ok, _} = Cachex.get(:myapp, "index.html")
+    assert ok == :ok
+  end
+
+end

test/myapp_web/controllers/thread_controller_test.exs

@@ -1,6 +1,5 @@
 defmodule MyAppWeb.ThreadControllerTest do
   use MyAppWeb.ConnCase, async: true
-  import MyAppWeb.ThreadController
   import MyApp.Data.TestHelpers
 
   test "insert new thread should fail" do