Starting a Genserver from executable

Questions / Help
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1

I want to start a genserver from executable binary. I can start the application by starting a node

iex --name n1@127.0.0.1 -S mix

Is there any way that I can start the server on a node without actually starting the node itself ?

defmodule SimpleCluster.CLI do
  def main(args \\ []) do
    SimpleCluster.Application.start(args)
  end
end

The application module looks like

defmodule SimpleCluster.Application do
  # See https://hexdocs.pm/elixir/Application.html
  # for more information on OTP Applications
  @moduledoc false

  use Application

  @impl true
  def start(_args) do
    children = [
      {Cluster.Supervisor, [topologies(), [name: SimpleCluster.ClusterSupervisor]]},
      SimpleCluster.Observer,
      SimpleCluster.Ping
    ]

    opts = [strategy: :one_for_one, name: LibclusterCluster.Supervisor]
    Supervisor.start_link(children, opts)
  end

  defp topologies do
    [
      example: [
        strategy: Cluster.Strategy.Epmd,
        config: [
          hosts: [
            :"n1@127.0.0.1",
            :"n2@127.0.0.1"
          ]
        ]
      ]
    ]
  end
end

and am using escript.build for making executable binary.

What I want is when I start the executable on one node, it starts the server and send me responses if it is alive or not. When I run the executable on a new node, I want it to start the server and then connect with the first node.

i have the code for that as well. The only issue is that I am not able to start the server from executable.

code for observer

defmodule SimpleCluster.Observer do
  @moduledoc """
  Simple process that monitors node changes in the
  current cluster.
  """

  use GenServer

  require Logger

  def start_link(_), do: GenServer.start_link(__MODULE__, Map.new())

  @impl GenServer
  def init(state) do
    :net_kernel.monitor_nodes(true)

    {:ok, state}
  end

  @impl GenServer
  def handle_info({:nodedown, node}, state) do
    # A node left the cluster
    Logger.info("--- Node down: #{node}")

    {:noreply, state}
  end

  def handle_info({:nodeup, node}, state) do
    # A new node joined the cluster
    Logger.info("--- Node up: #{node}")

    {:noreply, state}
  end
end