MULTIARCH-4552: Sync ImageStreamImportMode setting in the image config

As per openshift/enhancements#1605, there was a
new field introduced in the image config spec and status which reflects
the global value to be set for imagestream import mode which is behind a
featuregate. This PR sets the status field in the image config based on
the spec setting so it can be synced by the apiserver's observedconfig
to set the import mode for imagestreams.

Author: Prashanth684

pkg/operator/imageconfig.go

@@ -23,6 +23,7 @@ import (
 	configapi "github.com/openshift/api/config/v1"
 	operatorv1 "github.com/openshift/api/operator/v1"
 	configset "github.com/openshift/client-go/config/clientset/versioned/typed/config/v1"
+	configv1informers "github.com/openshift/client-go/config/informers/externalversions/config/v1"
 	routev1informers "github.com/openshift/client-go/route/informers/externalversions/route/v1"
 	routev1lister "github.com/openshift/client-go/route/listers/route/v1"
 	"github.com/openshift/library-go/pkg/operator/v1helpers"
@@ -36,26 +37,30 @@ import (
 // Watches for changes on image registry routes and services, updating
 // the resource status appropriately.
 type ImageConfigController struct {
-	configClient   configset.ConfigV1Interface
-	operatorClient v1helpers.OperatorClient
-	routeLister    routev1lister.RouteNamespaceLister
-	serviceLister  corev1listers.ServiceNamespaceLister
-	cachesToSync   []cache.InformerSynced
-	queue          workqueue.RateLimitingInterface
+	configClient                 configset.ConfigV1Interface
+	operatorClient               v1helpers.OperatorClient
+	routeLister                  routev1lister.RouteNamespaceLister
+	serviceLister                corev1listers.ServiceNamespaceLister
+	cachesToSync                 []cache.InformerSynced
+	queue                        workqueue.RateLimitingInterface
+	imageStreamImportModeEnabled bool
 }
 
 func NewImageConfigController(
 	configClient configset.ConfigV1Interface,
 	operatorClient v1helpers.OperatorClient,
 	routeInformer routev1informers.RouteInformer,
 	serviceInformer corev1informers.ServiceInformer,
+	imageConfigInformer configv1informers.ImageInformer,
+	imageStreamImportModeEnabled bool,
 ) (*ImageConfigController, error) {
 	icc := &ImageConfigController{
-		configClient:   configClient,
-		operatorClient: operatorClient,
-		routeLister:    routeInformer.Lister().Routes(defaults.ImageRegistryOperatorNamespace),
-		serviceLister:  serviceInformer.Lister().Services(defaults.ImageRegistryOperatorNamespace),
-		queue:          workqueue.NewNamedRateLimitingQueue(workqueue.DefaultControllerRateLimiter(), "ImageConfigController"),
+		configClient:                 configClient,
+		operatorClient:               operatorClient,
+		routeLister:                  routeInformer.Lister().Routes(defaults.ImageRegistryOperatorNamespace),
+		serviceLister:                serviceInformer.Lister().Services(defaults.ImageRegistryOperatorNamespace),
+		queue:                        workqueue.NewNamedRateLimitingQueue(workqueue.DefaultControllerRateLimiter(), "ImageConfigController"),
+		imageStreamImportModeEnabled: imageStreamImportModeEnabled,
 	}
 
 	if _, err := serviceInformer.Informer().AddEventHandler(icc.eventHandler()); err != nil {
@@ -68,6 +73,12 @@ func NewImageConfigController(
 	}
 	icc.cachesToSync = append(icc.cachesToSync, routeInformer.Informer().HasSynced)
 
+	if imageStreamImportModeEnabled {
+		if _, err := imageConfigInformer.Informer().AddEventHandler(icc.eventHandler()); err != nil {
+			return nil, err
+		}
+		icc.cachesToSync = append(icc.cachesToSync, imageConfigInformer.Informer().HasSynced)
+	}
 	return icc, nil
 }
 
@@ -159,6 +170,20 @@ func (icc *ImageConfigController) syncImageStatus() error {
 		cfg.Status.InternalRegistryHostname = internalHostname
 		modified = true
 	}
+	if icc.imageStreamImportModeEnabled {
+		var importmode configapi.ImportModeType
+		if cfg.Spec.ImageStreamImportMode != "" {
+			importmode = cfg.Spec.ImageStreamImportMode
+		} else {
+			// TODO: once clusterversion reports the type of payload in its status, use that to determine what the default will be
+			// i.e, multi payload => PreserveOriginal, single arch payload => Legacy
+			importmode = configapi.ImportModeLegacy
+		}
+		if cfg.Status.ImageStreamImportMode != importmode {
+			cfg.Status.ImageStreamImportMode = importmode
+			modified = true
+		}
+	}
 
 	if modified {
 		if _, err := icc.configClient.Images().UpdateStatus(context.TODO(), cfg, metav1.UpdateOptions{}); err != nil {

pkg/operator/starter.go

@@ -11,6 +11,7 @@ import (
 	"k8s.io/klog/v2"
 
 	configv1 "github.com/openshift/api/config/v1"
+	"github.com/openshift/api/features"
 	configclient "github.com/openshift/client-go/config/clientset/versioned"
 	configinformers "github.com/openshift/client-go/config/informers/externalversions"
 	imageclient "github.com/openshift/client-go/image/clientset/versioned"
@@ -110,11 +111,19 @@ func RunOperator(ctx context.Context, kubeconfig *restclient.Config) error {
 		return err
 	}
 
+	featureGates, err := featureGateAccessor.CurrentFeatureGates()
+	if err != nil {
+		return err
+	}
+	imageStreamImportModeEnabled := featureGates.Enabled(features.FeatureGateImageStreamImportMode)
+
 	imageConfigStatusController, err := NewImageConfigController(
 		configClient.ConfigV1(),
 		configOperatorClient,
 		routeInformers.Route().V1().Routes(),
 		kubeInformers.Core().V1().Services(),
+		configInformers.Config().V1().Images(),
+		imageStreamImportModeEnabled,
 	)
 	if err != nil {
 		return err