use Mix.Config

# Takes JOIN_TO env variable provided by deployer (if any) on starting this app 
# JOIN_TO may be a comma separated list of nodes. The app will connect to the first
# available foreign node. This way the list of nodes can be identical on all nodes
# and starting order of apps on different nodes doesn't matter.
config :distkv, node_addr: System.get_env("JOIN_TO")

def start(_type, args) do
    # Read provided :node_addr from config.exs
    node_addr = Application.get_env(:distkv, :node_addr)

    import Supervisor.Spec, warn: false

    # Define workers and child supervisors to be supervised
    children = [
      # Starts DkvServer (GenServer) with node_addr as argument
      worker(Distkv.DkvServer, [node_addr]),
    ]

    # See http://elixir-lang.org/docs/stable/elixir/Supervisor.html
    # for other strategies and supported options
    opts = [strategy: :one_for_one, name: Distkv.Supervisor]
    Supervisor.start_link(children, opts)
  end

C:\> set JOIN_TO=node_1@YOUR_IP,node_2@YOUR_IP,node_3@YOUR_IP
C:\> iex --name node_1@YOUR_IP --cookie freak -S mix run
iex(node_1@YOUR_IP)1> alias Distkv.DkvServer
iex(node_1@YOUR_IP)2> DkvServer.insert(:one, %{msg: "Hello World"})
:ok
iex(node_1@YOUR_IP)3> DkvServer.select_all
[%{msg: "Hello World"}]

C:\> set JOIN_TO=node_1@YOUR_IP,node_2@YOUR_IP,node_3@YOUR_IP
C:\> iex --name node_2@YOUR_IP --cookie freak -S mix run
iex(node_2@YOUR_IP)1> alias Distkv.DkvServer
iex(node_2@YOUR_IP)2> DkvServer.select_all
[%{msg: "Hello World"}]