StatefulSet: Cleanup the complex defer function updating the status

In the long term, the complex defer function makes the code harder to
maintain as code after it should take that into account. This removes
the complex defer function updating the status of a statefulset.

pkg/controller/statefulset/stateful_set_control_test.go

@@ -2106,6 +2106,78 @@ func TestStatefulSetAvailability(t *testing.T) {
 	}
 }
 
+func TestStatefulSetStatusUpdate(t *testing.T) {
+	var (
+		syncErr   = fmt.Errorf("sync error")
+		statusErr = fmt.Errorf("status error")
+	)
+
+	testCases := []struct {
+		desc string
+
+		hasSyncErr   bool
+		hasStatusErr bool
+
+		expectedErr error
+	}{
+		{
+			desc:         "no error",
+			hasSyncErr:   false,
+			hasStatusErr: false,
+			expectedErr:  nil,
+		},
+		{
+			desc:         "sync error",
+			hasSyncErr:   true,
+			hasStatusErr: false,
+			expectedErr:  syncErr,
+		},
+		{
+			desc:         "status error",
+			hasSyncErr:   false,
+			hasStatusErr: true,
+			expectedErr:  statusErr,
+		},
+		{
+			desc:         "sync and status error",
+			hasSyncErr:   true,
+			hasStatusErr: true,
+			expectedErr:  syncErr,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.desc, func(t *testing.T) {
+			set := newStatefulSet(3)
+			client := fake.NewSimpleClientset(set)
+			om, ssu, ssc := setupController(client)
+
+			if tc.hasSyncErr {
+				om.SetCreateStatefulPodError(syncErr, 0)
+			}
+			if tc.hasStatusErr {
+				ssu.SetUpdateStatefulSetStatusError(statusErr, 0)
+			}
+
+			selector, err := metav1.LabelSelectorAsSelector(set.Spec.Selector)
+			if err != nil {
+				t.Error(err)
+			}
+			pods, err := om.podsLister.Pods(set.Namespace).List(selector)
+			if err != nil {
+				t.Error(err)
+			}
+			_, err = ssc.UpdateStatefulSet(context.TODO(), set, pods)
+			if ssu.updateStatusTracker.requests != 1 {
+				t.Errorf("Did not update status")
+			}
+			if !errors.Is(err, tc.expectedErr) {
+				t.Errorf("Expected error: %v, got: %v", tc.expectedErr, err)
+			}
+		})
+	}
+}
+
 type requestTracker struct {
 	requests int
 	err      error