Made a more proper supervisor tree for the app

lib/neon_vertigo_service.ex

@@ -8,13 +8,10 @@ defmodule NeonVertigoService do
   @impl true
   def start(_start_type, _start_args) do
     children = [
-      # %{id: :emqtt, start: {:emqtt, :start_link, [[{:owner, self()}, {:username, "artemis"}, {:password, "artemis"}]]}}, 
-      {NeonVertigoService.Mqtt, [{}]}
+      NeonVertigoService.Mqtt.Supervisor,
     ]
 
     {:ok, _spid} = Supervisor.start_link(children, strategy: :one_for_one)
-    # {:ok, mqtt_pid} = Supervisor.start_child(spid, %{id: :emqtt, start: {:emqtt, :start_link, [[{:owner, self()}, {:username, "artemis"}, {:password, "artemis"}]]}})
-    # {:ok, _} = Supervisor.start_child(spid, {NeonVertigoService.Mqtt, [{mqtt_pid}]})
 
   end
 end

lib/neon_vertigo_service/mqtt.ex

@@ -1,25 +0,0 @@
-defmodule NeonVertigoService.Mqtt do
-  use GenServer
-
-  def start_link(_) do
-    GenServer.start_link(__MODULE__, {})
-  end
-  
-  def init(_) do
-    mqtt_config = Application.fetch_env!(:neon_vertigo_service, :mqtt_params)
-    {:ok, mqtt_pid} = :emqtt.start_link([{:owner, self()} | mqtt_config]) 
-    {:ok, _mqtt_props} = :emqtt.connect(mqtt_pid)
-    Process.link(mqtt_pid)
-
-    :emqtt.subscribe(mqtt_pid, %{}, [{"$share/neon-vertigo-service/test/+", [{:qos, 1}]}])
-
-    {:ok, {mqtt_pid}}
-  end
-
-  # Handling MQTT messages
-  def handle_info({:publish, msg}, state) do
-    IO.puts("Received message") 
-    IO.inspect(msg)
-    {:noreply, state}
-  end
-end

lib/neon_vertigo_service/mqtt/server.ex

@@ -0,0 +1,35 @@
+defmodule NeonVertigoService.Mqtt.Service do
+  use GenServer
+
+  def start_link(_) do
+    GenServer.start_link(__MODULE__, [], name: __MODULE__)
+  end
+  
+  def init(_) do
+    {:ok, {}, {:continue, :init_mqtt}}
+  end
+
+  # Callbacks
+  def handle_continue(:init_mqtt, {}) do
+    mqtt_config = Application.fetch_env!(:neon_vertigo_service, :mqtt_params)
+    {:ok, mqtt_pid} = Supervisor.start_child(
+        NeonVertigoService.Mqtt.Supervisor,
+        %{
+          id: :neon_vertigo_emqtt,
+          start: {:emqtt, :start_link, [[owner: self(), name: :neon_vertigo_service_emqtt] ++ mqtt_config]}
+          }
+        )
+    {:ok, _mqtt_props} = :emqtt.connect(mqtt_pid)
+
+    :emqtt.subscribe(mqtt_pid, %{}, [{"$share/neon-vertigo-service/test/+", [{:qos, 1}]}])
+
+    {:noreply, {mqtt_pid}}
+  end
+
+  # Handling MQTT messages
+  def handle_info({:publish, msg}, state) do
+    IO.puts("Received message") 
+    IO.inspect(msg)
+    {:noreply, state}
+  end
+end

lib/neon_vertigo_service/mqtt/supervisor.ex

@@ -0,0 +1,18 @@
+defmodule NeonVertigoService.Mqtt.Supervisor do
+  use Supervisor
+  
+  def start_link(init_arg) do
+    Supervisor.start_link(__MODULE__, init_arg, name: __MODULE__)
+  end
+
+# Callbacks
+
+  @impl true
+  def init(_init_arg) do
+    children = [
+      NeonVertigoService.Mqtt.Service
+    ]
+
+    Supervisor.init(children, strategy: :one_for_all)
+  end
+end