TcpServer Implementation with gen_tcp erlang module

tcp_server.ex

defmodule TcpServer do
  use GenServer

  def start_link() do
    ip = Application.get_env :tcp_server, :ip, {127,0,0,1}
    port = Application.get_env :tcp_server, :port, 6666
    GenServer.start_link(__MODULE__,[ip,port],[])
  end

  def init [ip,port] do
    {:ok,listen_socket}= :gen_tcp.listen(port,[:binary,{:packet, 0},{:active,true},{:ip,ip}])
    {:ok,socket } = :gen_tcp.accept listen_socket
    {:ok, %{ip: ip,port: port,socket: socket}}
  end

  def handle_info({:tcp,socket,packet},state) do
    IO.inspect packet, label: "incoming packet"
    :gen_tcp.send socket,"Hi Blackode \n"
    {:noreply,state}
  end

  def handle_info({:tcp_closed,socket},state) do
    IO.inspect "Socket has been closed"
    {:noreply,state}
  end

  def handle_info({:tcp_error,socket,reason},state) do
    IO.inspect socket,label: "connection closed dut to #{reason}"
    {:noreply,state}
  end

end