Fixing 2 bugs related to failure scenarios (#599)

First bug:
If during module deletion scenario, UnloadKmod function returns and
error for some reason, the GarbageCollectInUseLabels and UpdateNodeLabelsAndRecordEvents
onw't be called. This in turn means, that if there is a module that was
being loaded/unloaded in parallel, the actual action will happen
(load/unload from kernel), but the label in NMC and node won't be
updated.
Solution: always continue with GarbageCollectInUseLabels
and UpdateNodeLabelsAndRecordEvents and return a collective error later

Second bug:
In case ProcessModuleSpec from some spec/status has failed, the status
would not be deleted from the statusMap, which will cause it later to be
treated as orphaned status and the UnloadKmod to be called.
Solution: always delete status from statusMap, even in case of a failure

internal/controllers/nmc_reconciler.go

@@ -125,10 +125,10 @@ func (r *NMCReconciler) Reconcile(ctx context.Context, req reconcile.Request) (r
 				errs,
 				fmt.Errorf("error processing Module %s: %v", moduleNameKey, err),
 			)
-
-			continue
 		}
 
+		// deleting status always (even in case of an error), so that it won't be treated
+		// as an orphaned status later in reconciliation
 		delete(statusMap, moduleNameKey)
 	}
 
@@ -146,19 +146,15 @@ func (r *NMCReconciler) Reconcile(ctx context.Context, req reconcile.Request) (r
 		}
 	}
 
-	if err := errors.Join(errs...); err != nil {
-		return reconcile.Result{}, fmt.Errorf("could not process orphan statuses: %v", err)
-	}
-
 	if err := r.helper.GarbageCollectInUseLabels(ctx, &nmcObj); err != nil {
-		return reconcile.Result{}, fmt.Errorf("could not garbage collect in-use labels for NMC %s: %v", req.NamespacedName, err)
+		errs = append(errs, fmt.Errorf("failed to GC in-use labels for NMC %s: %v", req.NamespacedName, err))
 	}
 
 	if err := r.helper.UpdateNodeLabelsAndRecordEvents(ctx, &nmcObj); err != nil {
-		return reconcile.Result{}, fmt.Errorf("could not update node's labels for NMC %s: %v", req.NamespacedName, err)
+		errs = append(errs, fmt.Errorf("could not update node's labels for NMC %s: %v", req.NamespacedName, err))
 	}
 
-	return ctrl.Result{}, nil
+	return ctrl.Result{}, errors.Join(errs...)
 }
 
 func (r *NMCReconciler) SetupWithManager(ctx context.Context, mgr manager.Manager) error {

internal/controllers/nmc_reconciler_test.go

@@ -162,6 +162,65 @@ var _ = Describe("NodeModulesConfigReconciler_Reconcile", func() {
 			BeZero(),
 		)
 	})
+
+	It("should complete all the reconcile functions and return combined error", func() {
+		const (
+			mod0Name = "mod0"
+			mod1Name = "mod1"
+			mod2Name = "mod2"
+		)
+		spec0 := kmmv1beta1.NodeModuleSpec{
+			ModuleItem: kmmv1beta1.ModuleItem{
+				Namespace: namespace,
+				Name:      mod0Name,
+			},
+		}
+
+		status0 := kmmv1beta1.NodeModuleStatus{
+			ModuleItem: kmmv1beta1.ModuleItem{
+				Namespace: namespace,
+				Name:      mod0Name,
+			},
+		}
+
+		status2 := kmmv1beta1.NodeModuleStatus{
+			ModuleItem: kmmv1beta1.ModuleItem{
+				Namespace: namespace,
+				Name:      mod2Name,
+			},
+		}
+
+		nmc := &kmmv1beta1.NodeModulesConfig{
+			ObjectMeta: metav1.ObjectMeta{Name: nmcName},
+			Spec: kmmv1beta1.NodeModulesConfigSpec{
+				Modules: []kmmv1beta1.NodeModuleSpec{spec0},
+			},
+			Status: kmmv1beta1.NodeModulesConfigStatus{
+				Modules: []kmmv1beta1.NodeModuleStatus{status0, status2},
+			},
+		}
+
+		contextWithValueMatch := gomock.AssignableToTypeOf(
+			reflect.TypeOf((*context.Context)(nil)).Elem(),
+		)
+
+		gomock.InOrder(
+			kubeClient.
+				EXPECT().
+				Get(ctx, nmcNsn, &kmmv1beta1.NodeModulesConfig{}).
+				Do(func(_ context.Context, _ types.NamespacedName, kubeNmc ctrlclient.Object, _ ...ctrlclient.Options) {
+					*kubeNmc.(*kmmv1beta1.NodeModulesConfig) = *nmc
+				}),
+			wh.EXPECT().SyncStatus(ctx, nmc).Return(nil),
+			wh.EXPECT().ProcessModuleSpec(contextWithValueMatch, nmc, &spec0, &status0).Return(fmt.Errorf("some error")),
+			wh.EXPECT().ProcessUnconfiguredModuleStatus(contextWithValueMatch, nmc, &status2).Return(fmt.Errorf("some error")),
+			wh.EXPECT().GarbageCollectInUseLabels(ctx, nmc).Return(fmt.Errorf("some error")),
+			wh.EXPECT().UpdateNodeLabelsAndRecordEvents(ctx, nmc).Return(fmt.Errorf("some error")),
+		)
+
+		_, err := r.Reconcile(ctx, req)
+		Expect(err).ToNot(BeNil())
+	})
 })
 
 var moduleConfig = kmmv1beta1.ModuleConfig{