update_campaigns: spawn executor when creating a campaign

Also add relevant tests

backend/lib/edgehog/update_campaigns.ex

@@ -29,6 +29,7 @@ defmodule Edgehog.UpdateCampaigns do
   alias Ecto.Multi
   alias Edgehog.BaseImages
   alias Edgehog.Devices
+  alias Edgehog.UpdateCampaigns.ExecutorSupervisor
   alias Edgehog.UpdateCampaigns.Target
   alias Edgehog.UpdateCampaigns.UpdateCampaign
   alias Edgehog.UpdateCampaigns.UpdateChannel
@@ -452,6 +453,9 @@ defmodule Edgehog.UpdateCampaigns do
       end,
       placeholders: placeholders
     )
+    |> Multi.run(:executor, fn _repo, %{update_campaign: update_campaign} ->
+      ExecutorSupervisor.start_executor(update_campaign)
+    end)
     |> Repo.transaction()
     |> case do
       {:ok, %{update_campaign: update_campaign}} ->

backend/test/edgehog/update_campaigns_test.exs

@@ -30,6 +30,7 @@ defmodule Edgehog.UpdateCampaignsTest do
   alias Edgehog.DevicesFixtures
   alias Edgehog.Groups
   alias Edgehog.UpdateCampaigns
+  alias Edgehog.UpdateCampaigns.ExecutorRegistry
   alias Edgehog.UpdateCampaigns.PushRollout
   alias Edgehog.UpdateCampaigns.UpdateCampaign
   alias Edgehog.UpdateCampaigns.UpdateChannel
@@ -338,6 +339,9 @@ defmodule Edgehog.UpdateCampaignsTest do
       assert update_campaign.update_targets == []
       assert update_campaign.status == :finished
       assert update_campaign.outcome == :success
+
+      # Check that no executor got started
+      assert :error = fetch_update_campaign_executor_pid(update_campaign)
     end
 
     test "with some targets creates an :idle update_campaign" do
@@ -357,6 +361,10 @@ defmodule Edgehog.UpdateCampaignsTest do
       assert target.device_id == device.id
       assert update_campaign.status == :idle
       assert update_campaign.outcome == nil
+
+      # Check that the executor got started
+      assert {:ok, pid} = fetch_update_campaign_executor_pid(update_campaign)
+      assert {:wait_for_start_execution, _data} = :sys.get_state(pid)
     end
 
     test "fails with invalid rollout mechanism" do
@@ -551,6 +559,15 @@ defmodule Edgehog.UpdateCampaignsTest do
     UpdateCampaigns.create_update_campaign(update_channel, base_image, attrs)
   end
 
+  defp fetch_update_campaign_executor_pid(update_campaign) do
+    key = {update_campaign.tenant_id, update_campaign.id}
+
+    case Registry.lookup(ExecutorRegistry, key) do
+      [] -> :error
+      [{pid, _}] -> {:ok, pid}
+    end
+  end
+
   defp device_fixture do
     # Helper to avoid having to manually create the cluster and realm
     # TODO: this will be eliminated once we have proper lazy fixtures (see issue #267)