PR: Add /ping endpoint and image to Wake Heroku Dyno

README.md

@@ -175,6 +175,9 @@ Try the Heroku example version so you know what to expect.
 #### Browser 📱
 
 Visit: https://phoenix-content-negotiation.herokuapp.com
+<!-- see: https://github.com/dwyl/ping -->
+![wake-sleeping-heroku-app](https://phoenix-content-negotiation.herokuapp.com/ping)
+
 
 You should see a random inspiring quote:
 
@@ -1604,7 +1607,7 @@ Randomized with seed 452478
 
 ### 10. View `JSON` in a Web Browser
 
-Sometimes while you are testing, 
+Sometimes while you are testing,
 you want to view the `JSON` data in Web Browser.
 The `content` package allows you to add `.json`
 to _any_ route directly in the browser's URL field
@@ -1622,7 +1625,7 @@ There are two steps to enable this:
 get "/*wildcard", QuotesController, :redirect
 ```
 
-e.g: 
+e.g:
 [`/lib/app_web/router.ex#L21`](https://github.com/dwyl/phoenix-content-negotiation-tutorial/blob/ffaeecd5fc0712631563e37c3315704e1853b68a/lib/app_web/router.ex#L21)
 
 
@@ -1634,13 +1637,13 @@ def redirect(conn, params) do
 end
 ```
 
-e.g: 
+e.g:
 [`/lib/app_web/controllers/quotes_controller.ex#L16-L18`](https://github.com/dwyl/phoenix-content-negotiation-tutorial/blob/ffaeecd5fc0712631563e37c3315704e1853b68a/lib/app_web/controllers/quotes_controller.ex#L16-L18)
 
 
 
-You can now visit 
-[http://localhost:4000/.json](http://localhost:4000/.json) 
+You can now visit
+[http://localhost:4000/.json](http://localhost:4000/.json)
 in your web browser
 to view a random quote in `JSON` format:
 

lib/app_web/controllers/ping_controller.ex

@@ -0,0 +1,8 @@
+defmodule AppWeb.PingController do
+  use AppWeb, :controller
+
+  # see: github.com/dwyl/ping
+  def ping(conn, params) do
+    Ping.render_pixel(conn, params)
+  end
+end

lib/app_web/router.ex

@@ -18,6 +18,7 @@ defmodule AppWeb.Router do
     pipe_through :any
 
     get "/", QuotesController, :index
+    get "/ping", PingController, :ping
     get "/*wildcard", QuotesController, :redirect
   end
 end

mix.exs

@@ -57,6 +57,9 @@ defmodule App.MixProject do
       # content negotiation plug: https://github.com/dwyl/content
       {:content, "~> 1.3.0"},
 
+      # ping to wake the ("Free") Heroku dyno: https://github.com/dwyl/ping
+      {:ping, "~> 1.0.0"},
+
       # Test Code Coverage:
       {:excoveralls, "~> 0.12.2", only: :test}
     ]

mix.lock

@@ -19,6 +19,7 @@
   "phoenix_live_reload": {:hex, :phoenix_live_reload, "1.2.1", "274a4b07c4adbdd7785d45a8b0bb57634d0b4f45b18d2c508b26c0344bd59b8f", [:mix], [{:file_system, "~> 0.2.1 or ~> 0.3", [hex: :file_system, repo: "hexpm", optional: false]}, {:phoenix, "~> 1.4", [hex: :phoenix, repo: "hexpm", optional: false]}], "hexpm", "41b4103a2fa282cfd747d377233baf213c648fdcc7928f432937676532490eee"},
   "phoenix_live_view": {:hex, :phoenix_live_view, "0.12.1", "42f591c781edbf9fab921319076b7ac635d43aa23e6748d2644563326236d7e4", [:mix], [{:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: true]}, {:phoenix, "~> 1.4.16 or ~> 1.5.0", [hex: :phoenix, repo: "hexpm", optional: false]}, {:phoenix_html, "~> 2.14", [hex: :phoenix_html, repo: "hexpm", optional: false]}], "hexpm", "585321e98df1cd5943e370b9784e950a37ca073744eb534660c9048967c52ab6"},
   "phoenix_pubsub": {:hex, :phoenix_pubsub, "2.0.0", "a1ae76717bb168cdeb10ec9d92d1480fec99e3080f011402c0a2d68d47395ffb", [:mix], [], "hexpm", "c52d948c4f261577b9c6fa804be91884b381a7f8f18450c5045975435350f771"},
+  "ping": {:hex, :ping, "1.0.0", "d692c1b8b45fd8ad188c75dfc871639d1e528bcca46b36dccf5cb04c35d7f460", [:mix], [], "hexpm", "e2b2c63e5741827e786674ce7083c3784a51f03bd34237a31364670b51421675"},
   "plug": {:hex, :plug, "1.10.1", "c56a6d9da7042d581159bcbaef873ba9d87f15dce85420b0d287bca19f40f9bd", [:mix], [{:mime, "~> 1.0", [hex: :mime, repo: "hexpm", optional: false]}, {:plug_crypto, "~> 1.1.1 or ~> 1.2", [hex: :plug_crypto, repo: "hexpm", optional: false]}, {:telemetry, "~> 0.4", [hex: :telemetry, repo: "hexpm", optional: true]}], "hexpm", "b5cd52259817eb8a31f2454912ba1cff4990bca7811918878091cb2ab9e52cb8"},
   "plug_cowboy": {:hex, :plug_cowboy, "2.2.2", "7a09aa5d10e79b92d332a288f21cc49406b1b994cbda0fde76160e7f4cc890ea", [:mix], [{:cowboy, "~> 2.7", [hex: :cowboy, repo: "hexpm", optional: false]}, {:plug, "~> 1.7", [hex: :plug, repo: "hexpm", optional: false]}, {:telemetry, "~> 0.4", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "e82364b29311dbad3753d588febd7e5ef05062cd6697d8c231e0e007adab3727"},
   "plug_crypto": {:hex, :plug_crypto, "1.1.2", "bdd187572cc26dbd95b87136290425f2b580a116d3fb1f564216918c9730d227", [:mix], [], "hexpm", "6b8b608f895b6ffcfad49c37c7883e8df98ae19c6a28113b02aa1e9c5b22d6b5"},

test/app_web/controllers/ping_controller_test.exs

@@ -0,0 +1,12 @@
+defmodule AppWeb.PingControllerTest do
+  use AppWeb.ConnCase
+
+  describe "/ping" do
+    test "GET /ping (GIF) renders 1x1 pixel", %{conn: conn} do
+      conn = get(conn, Routes.ping_path(conn, :ping))
+      assert conn.status == 200
+      assert conn.state == :sent
+      assert conn.resp_body =~ <<71, 73, 70, 56, 57>>
+    end
+  end
+end