Level up our echo serverv0.3.0

This should enable upgrade process to retain connections

*   Replace our simple task supervisor with a custom `simple_one_for_one`
    supervisor

*   Upgrade our echo server to use a `GenServer` behaviour

1 files changed, 16 insertions, 12 deletions

diff --git a/lib/octochat/servers/echo.ex b/lib/octochat/servers/echo.ex
index da04876..bea9864 100644
--- a/lib/octochat/servers/echo.ex
+++ b/lib/octochat/servers/echo.ex
@@ -2,23 +2,27 @@ defmodule Octochat.Echo do
   @moduledoc """
   Octochat Echo server
   """
+  use GenServer
   require Logger
 
-  def serve(socket) do
-    socket
-      |> read_line()
-      |> write_line!(socket)
+  def start_link(socket) do
+    GenServer.start_link(__MODULE__, socket)
+  end
 
-    serve(socket)
+  def init(socket) do
+    :ok = :inet.setopts(socket, active: true)
+    {:ok, %{socket: socket}}
+  end
+
+  def handle_info({:tcp, _, msg}, state = %{socket: socket}) do
+    msg
+      |> write_line!(socket)
+    {:noreply, state}
   end
 
-  defp read_line(socket) do
-    case :gen_tcp.recv(socket, 0) do
-      {:ok, line} -> line
-      {:error, reason} ->
-        Logger.error(reason)
-        Process.exit(self, :normal)
-    end
+  def handle_info({:tcp_closed, _}, state) do
+    Logger.info("#{__MODULE__}: Connection closing")
+    {:stop, :normal, %{}}
   end
 
   defp write_line!(line, socket) do