pass context along with pubsub message

Author: RudolfMan

lib/acme/orders.ex

@@ -3,6 +3,8 @@ defmodule Acme.Orders do
   The Orders context.
   """
 
+  require OpenTelemetry.Tracer
+
   import Ecto.Query, warn: false
   alias Acme.Repo
 
@@ -68,11 +70,15 @@ defmodule Acme.Orders do
 
   """
   def update_order(%Order{} = order, attrs) do
-    order_changeset = Order.changeset(order, attrs)
+    OpenTelemetry.Tracer.with_span "orders:update_order" do
+      order_changeset = Order.changeset(order, attrs)
+
+      with {:ok, order} <- Repo.update(order_changeset) do
+        ctx = OpenTelemetry.Tracer.current_span_ctx()
+        Phoenix.PubSub.broadcast(Acme.PubSub, "orders:#{order.id}", {:order_updated, order, ctx})
 
-    with {:ok, order} <- Repo.update(order_changeset) do
-      Phoenix.PubSub.broadcast(Acme.PubSub, "orders:#{order.id}", {:order_updated, order})
-      {:ok, order}
+        {:ok, order}
+      end
     end
   end
 

lib/acme_web/live/order_live/show.ex

@@ -21,7 +21,9 @@ defmodule AcmeWeb.OrderLive.Show do
   end
 
   @impl true
-  def handle_info({:order_updated, order}, socket) do
+  def handle_info({:order_updated, order, ctx}, socket) do
+    OpenTelemetry.Tracer.set_current_span(ctx)
+
     opts = %{attributes: %{user: inspect(self())}}
 
     OpenTelemetry.Tracer.with_span "order_live.show:order_updated", opts do