availableupdates: Unify capitalization when comparing architectures

Otherwise, the following condition in cincinnati.go in MultiArch clusters:

```
    if desiredArch == string(configv1.ClusterVersionArchitectureMulti) && currentArch != desiredArch {
        return current, []configv1.Release{current}, nil, nil
    }
```

gets evaluated to:

```
    if "Multi" == string(configv1.ClusterVersionArchitectureMulti) && "multi" != "Multi" {
        return current, []configv1.Release{current}, nil, nil
    }
```

This will cause MultiArch clusters with a set non-empty
`ClusterVersion.Spec.DesiredUpdate.Architecture` field to indefinitely
have available updates set to `[]configv1.Release{current}` because
the `"multi" != "Multi"` logic will always match.

Author: DavidHurta

pkg/cvo/availableupdates.go

@@ -52,7 +52,7 @@ func (optr *Operator) syncAvailableUpdates(ctx context.Context, config *configv1
 	currentArch := runtime.GOARCH
 
 	if optr.release.Architecture == configv1.ClusterVersionArchitectureMulti {
-		currentArch = "multi"
+		currentArch = string(configv1.ClusterVersionArchitectureMulti)
 	}
 
 	if desiredArch == "" {

pkg/cvo/availableupdates_test.go

@@ -111,22 +111,27 @@ func osusWithSingleConditionalEdge() (*httptest.Server, clusterconditions.Condit
 	return osus, mockPromql, updates, from
 }
 
-func newOperator(url, version string, promqlMock clusterconditions.Condition) (*availableUpdates, *Operator) {
-	currentRelease := configv1.Release{Version: version, Image: "payload/" + version}
+func newOperator(url, version string, promqlMock clusterconditions.Condition, arch string) (*availableUpdates, *Operator) {
+	var currentReleaseArch configv1.ClusterVersionArchitecture
+	if arch == string(configv1.ClusterVersionArchitectureMulti) {
+		currentReleaseArch = configv1.ClusterVersionArchitectureMulti
+	}
+	currentRelease := configv1.Release{Version: version, Image: "payload/" + version, Architecture: currentReleaseArch}
+
 	registry := clusterconditions.NewConditionRegistry()
 	registry.Register("Always", &always.Always{})
 	registry.Register("PromQL", promqlMock)
 	operator := &Operator{
 		updateService:         url,
-		architecture:          "amd64",
+		architecture:          arch,
 		proxyLister:           notFoundProxyLister{},
 		cmConfigManagedLister: notFoundConfigMapLister{},
 		conditionRegistry:     registry,
 		queue:                 workqueue.NewTypedRateLimitingQueue[any](workqueue.DefaultTypedControllerRateLimiter[any]()),
 		release:               currentRelease,
 	}
 	availableUpdates := &availableUpdates{
-		Architecture: runtime.GOARCH,
+		Architecture: arch,
 		Current:      configv1.Release{Version: version, Image: "payload/" + version},
 	}
 	return availableUpdates, operator
@@ -149,7 +154,7 @@ var availableUpdatesCmpOpts = []cmp.Option{
 func TestSyncAvailableUpdates(t *testing.T) {
 	fakeOsus, mockPromql, expectedConditionalUpdates, version := osusWithSingleConditionalEdge()
 	defer fakeOsus.Close()
-	expectedAvailableUpdates, optr := newOperator(fakeOsus.URL, version, mockPromql)
+	expectedAvailableUpdates, optr := newOperator(fakeOsus.URL, version, mockPromql, runtime.GOARCH)
 	expectedAvailableUpdates.UpdateService = fakeOsus.URL
 	expectedAvailableUpdates.ConditionalUpdates = expectedConditionalUpdates
 	expectedAvailableUpdates.Channel = cvFixture.Spec.Channel
@@ -231,7 +236,7 @@ func TestSyncAvailableUpdates_ConditionalUpdateRecommendedConditions(t *testing.
 		t.Run(tc.name, func(t *testing.T) {
 			fakeOsus, mockPromql, conditionalUpdates, version := osusWithSingleConditionalEdge()
 			defer fakeOsus.Close()
-			availableUpdates, optr := newOperator(fakeOsus.URL, version, mockPromql)
+			availableUpdates, optr := newOperator(fakeOsus.URL, version, mockPromql, runtime.GOARCH)
 			optr.availableUpdates = availableUpdates
 			optr.availableUpdates.ConditionalUpdates = conditionalUpdates
 			expectedConditions := []metav1.Condition{{}}
@@ -435,3 +440,58 @@ func TestEvaluateConditionalUpdate(t *testing.T) {
 		})
 	}
 }
+
+func TestSyncAvailableUpdatesMultiArchAfterMigration(t *testing.T) {
+	fakeOsus, mockPromql, expectedConditionalUpdates, version := osusWithSingleConditionalEdge()
+	defer fakeOsus.Close()
+
+	expectedAvailableUpdates, optr := newOperator(fakeOsus.URL, version, mockPromql, "Multi")
+
+	cv := cvFixture.DeepCopy()
+	cv.Spec.DesiredUpdate = &configv1.Update{
+		Architecture: configv1.ClusterVersionArchitectureMulti,
+		Version:      version,
+		Image:        optr.release.Image,
+		Force:        false,
+	}
+
+	expectedAvailableUpdates.UpdateService = fakeOsus.URL
+	expectedAvailableUpdates.ConditionalUpdates = expectedConditionalUpdates
+	expectedAvailableUpdates.Channel = cv.Spec.Channel
+	expectedAvailableUpdates.Condition = configv1.ClusterOperatorStatusCondition{
+		Type:   configv1.RetrievedUpdates,
+		Status: configv1.ConditionTrue,
+	}
+
+	err := optr.syncAvailableUpdates(context.Background(), cv)
+
+	if err != nil {
+		t.Fatalf("syncAvailableUpdates() unexpected error: %v", err)
+	}
+	if diff := cmp.Diff(expectedAvailableUpdates, optr.availableUpdates, availableUpdatesCmpOpts...); diff != "" {
+		t.Fatalf("available updates differ from expected:\n%s", diff)
+	}
+}
+
+func TestSyncAvailableUpdatesMultiArchAfterMigrationDesiredUpdateNil(t *testing.T) {
+	fakeOsus, mockPromql, expectedConditionalUpdates, version := osusWithSingleConditionalEdge()
+	defer fakeOsus.Close()
+
+	expectedAvailableUpdates, optr := newOperator(fakeOsus.URL, version, mockPromql, "Multi")
+	expectedAvailableUpdates.UpdateService = fakeOsus.URL
+	expectedAvailableUpdates.ConditionalUpdates = expectedConditionalUpdates
+	expectedAvailableUpdates.Channel = cvFixture.Spec.Channel
+	expectedAvailableUpdates.Condition = configv1.ClusterOperatorStatusCondition{
+		Type:   configv1.RetrievedUpdates,
+		Status: configv1.ConditionTrue,
+	}
+
+	err := optr.syncAvailableUpdates(context.Background(), cvFixture)
+
+	if err != nil {
+		t.Fatalf("syncAvailableUpdates() unexpected error: %v", err)
+	}
+	if diff := cmp.Diff(expectedAvailableUpdates, optr.availableUpdates, availableUpdatesCmpOpts...); diff != "" {
+		t.Fatalf("available updates differ from expected:\n%s", diff)
+	}
+}