From 5ba5f67b6173a8e5848b44528f09982ebd9d57f5 Mon Sep 17 00:00:00 2001
From: Nico Schieder <nschieder@redhat.com>
Date: Tue, 4 Nov 2025 14:35:08 +0100
Subject: [PATCH] Fix Collision error not reported when paused

---
 machinery/objects.go      |  11 ++--
 machinery/objects_test.go | 104 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 112 insertions(+), 3 deletions(-)

diff --git a/machinery/objects.go b/machinery/objects.go
index 96b4fb24..8550e0b3 100644
--- a/machinery/objects.go
+++ b/machinery/objects.go
@@ -226,7 +226,7 @@ func (e *ObjectEngine) Reconcile(
 			return nil, fmt.Errorf("creating resource: %w", err)
 		}
 
-		if err := e.migrateFieldManagersToSSA(ctx, desiredObject); err != nil {
+		if err := e.migrateFieldManagersToSSA(ctx, desiredObject, options); err != nil {
 			return nil, fmt.Errorf("migrating to SSA after create: %w", err)
 		}
 
@@ -441,7 +441,7 @@ func (e *ObjectEngine) create(
 	options types.ObjectReconcileOptions, opts ...client.CreateOption,
 ) error {
 	if options.Paused {
-		return nil
+		opts = append(opts, client.DryRunAll)
 	}
 
 	return e.writer.Create(ctx, obj, opts...)
@@ -458,7 +458,7 @@ func (e *ObjectEngine) patch(
 		return nil
 	}
 
-	if err := e.migrateFieldManagersToSSA(ctx, obj); err != nil {
+	if err := e.migrateFieldManagersToSSA(ctx, obj, options); err != nil {
 		return err
 	}
 
@@ -543,7 +543,12 @@ func (e *ObjectEngine) getObjectRevision(obj client.Object) (int64, error) {
 // SSA really is complicated: https://github.com/kubernetes/kubernetes/issues/99003
 func (e *ObjectEngine) migrateFieldManagersToSSA(
 	ctx context.Context, object Object,
+	options types.ObjectReconcileOptions,
 ) error {
+	if options.Paused {
+		return nil
+	}
+
 	patch, err := csaupgrade.UpgradeManagedFieldsPatch(
 		object, sets.New(e.fieldOwner), e.fieldOwner)
 
diff --git a/machinery/objects_test.go b/machinery/objects_test.go
index 8b6af075..2527b26f 100644
--- a/machinery/objects_test.go
+++ b/machinery/objects_test.go
@@ -861,6 +861,110 @@ func TestObjectEngine(t *testing.T) {
 	}
 }
 
+func TestObjectEngine_Collision(t *testing.T) {
+	t.Parallel()
+
+	owner := &corev1.ConfigMap{
+		ObjectMeta: metav1.ObjectMeta{
+			UID:       "12345-678",
+			Name:      "owner",
+			Namespace: "test",
+		},
+	}
+
+	t.Run("non paused", func(t *testing.T) {
+		t.Parallel()
+
+		cache := &cacheMock{}
+		writer := testutil.NewClient()
+		ownerStrategy := ownerhandling.NewNative(scheme.Scheme)
+		divergeDetector := &comparatorMock{}
+
+		oe := NewObjectEngine(
+			scheme.Scheme,
+			cache, writer,
+			ownerStrategy, divergeDetector,
+			testFieldOwner,
+			testSystemPrefix,
+		)
+		configMap := &corev1.ConfigMap{
+			ObjectMeta: metav1.ObjectMeta{
+				Name:      "oe-test",
+				Namespace: "test",
+			},
+			Data: map[string]string{
+				"test1": "test",
+				"test2": "test",
+			},
+		}
+
+		ctx := t.Context()
+
+		cache.
+			On("Get", mock.Anything, client.ObjectKeyFromObject(configMap), mock.Anything, mock.Anything).
+			Return(errors.NewNotFound(schema.GroupResource{}, ""))
+
+		writer.
+			On("Create", mock.Anything, mock.Anything, mock.Anything).
+			Return(errors.NewAlreadyExists(schema.GroupResource{
+				Group: "test", Resource: "banana",
+			}, "cavendish"))
+
+		_, err := oe.Reconcile(ctx, owner, 1, configMap)
+
+		var terr *CreateCollisionError
+
+		require.ErrorAs(t, err, &terr)
+		require.EqualError(t, err, `banana.test "cavendish" already exists`)
+	})
+
+	t.Run("paused", func(t *testing.T) {
+		t.Parallel()
+
+		cache := &cacheMock{}
+		writer := testutil.NewClient()
+		ownerStrategy := ownerhandling.NewNative(scheme.Scheme)
+		divergeDetector := &comparatorMock{}
+
+		oe := NewObjectEngine(
+			scheme.Scheme,
+			cache, writer,
+			ownerStrategy, divergeDetector,
+			testFieldOwner,
+			testSystemPrefix,
+		)
+		configMap := &corev1.ConfigMap{
+			ObjectMeta: metav1.ObjectMeta{
+				Name:      "oe-test",
+				Namespace: "test",
+			},
+			Data: map[string]string{
+				"test1": "test",
+				"test2": "test",
+			},
+		}
+
+		ctx := t.Context()
+
+		cache.
+			On("Get", mock.Anything, client.ObjectKeyFromObject(configMap), mock.Anything, mock.Anything).
+			Return(errors.NewNotFound(schema.GroupResource{}, ""))
+
+		writer.
+			On("Create", mock.Anything, mock.Anything, mock.Anything).
+			Return(errors.NewAlreadyExists(schema.GroupResource{
+				Group: "test", Resource: "banana",
+			}, "cavendish"))
+
+		_, err := oe.Reconcile(ctx, owner, 1, configMap, types.WithPaused{})
+
+		var terr *CreateCollisionError
+
+		require.ErrorAs(t, err, &terr)
+		require.EqualError(t, err, `banana.test "cavendish" already exists`)
+	})
+}
+
 func TestObjectEngine_Reconcile_SanityChecks(t *testing.T) {
 	t.Parallel()