MULTIARCH-4558: Set default for imagestreamImportMode based on observed config changes 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 reads the observed config, checks if the importmode
string is present and uses it as the default when creating imagestreams.

Author: Prashanth684

pkg/cmd/openshift-apiserver/openshiftapiserver/config.go

@@ -17,6 +17,7 @@ import (
 	routehostassignment "github.com/openshift/library-go/pkg/route/hostassignment"
 	"github.com/openshift/openshift-apiserver/pkg/cmd/openshift-apiserver/openshiftadmission"
 	"github.com/openshift/openshift-apiserver/pkg/cmd/openshift-apiserver/openshiftapiserver/configprocessing"
+	apisimage "github.com/openshift/openshift-apiserver/pkg/image/apis/image"
 	"github.com/openshift/openshift-apiserver/pkg/image/apiserver/registryhostname"
 	"github.com/openshift/openshift-apiserver/pkg/version"
 	"github.com/spf13/pflag"
@@ -264,6 +265,7 @@ func NewOpenshiftAPIConfig(config *openshiftcontrolplanev1.OpenShiftAPIServerCon
 			AllowedRegistriesForImport:         config.ImagePolicyConfig.AllowedRegistriesForImport,
 			MaxImagesBulkImportedPerRepository: config.ImagePolicyConfig.MaxImagesBulkImportedPerRepository,
 			AdditionalTrustedCA:                caData,
+			ImageStreamImportMode:              apisimage.ImportModeType(config.ImagePolicyConfig.ImageStreamImportMode),
 			RouteAllocator:                     routeAllocator,
 			AllowRouteExternalCertificates:     feature.DefaultFeatureGate.Enabled(featuregate.Feature(openshiftfeatures.FeatureGateRouteExternalCertificate)),
 			ProjectAuthorizationCache:          projectAuthorizationCache,

pkg/cmd/openshift-apiserver/openshiftapiserver/openshift_apiserver.go

@@ -44,6 +44,7 @@ import (
 	"github.com/openshift/openshift-apiserver/pkg/bootstrappolicy"
 	buildapiserver "github.com/openshift/openshift-apiserver/pkg/build/apiserver"
 	"github.com/openshift/openshift-apiserver/pkg/cmd/openshift-apiserver/openshiftapiserver/configprocessing"
+	apisimage "github.com/openshift/openshift-apiserver/pkg/image/apis/image"
 	imageapiserver "github.com/openshift/openshift-apiserver/pkg/image/apiserver"
 	"github.com/openshift/openshift-apiserver/pkg/image/apiserver/registryhostname"
 	projectapiserver "github.com/openshift/openshift-apiserver/pkg/project/apiserver"
@@ -87,6 +88,7 @@ type OpenshiftAPIExtraConfig struct {
 	AllowedRegistriesForImport         openshiftcontrolplanev1.AllowedRegistries
 	MaxImagesBulkImportedPerRepository int
 	AdditionalTrustedCA                []byte
+	ImageStreamImportMode              apisimage.ImportModeType
 
 	RouteAllocator                 *routehostassignment.SimpleAllocationPlugin
 	AllowRouteExternalCertificates bool
@@ -146,7 +148,11 @@ func (c *OpenshiftAPIExtraConfig) Validate() error {
 	if c.RESTMapper == nil {
 		ret = append(ret, fmt.Errorf("RESTMapper is required"))
 	}
-
+	if len(c.ImageStreamImportMode) > 0 {
+		if (c.ImageStreamImportMode != apisimage.ImportModeLegacy) && (c.ImageStreamImportMode != apisimage.ImportModePreserveOriginal) {
+			ret = append(ret, fmt.Errorf("Invalid value for import mode"))
+		}
+	}
 	return utilerrors.NewAggregate(ret)
 }
 
@@ -505,6 +511,10 @@ func (c completedConfig) New(delegationTarget genericapiserver.DelegationTarget)
 		GenericAPIServer: genericServer,
 	}
 
+	if len(c.ExtraConfig.ImageStreamImportMode) > 0 {
+		apisimage.DefaultImportMode = c.ExtraConfig.ImageStreamImportMode
+	}
+
 	// this remains a non-healthz endpoint so that you can be healthy without being ready.
 	addReadinessCheckRoute(s.GenericAPIServer.Handler.NonGoRestfulMux, "/healthz/ready", c.ExtraConfig.ProjectAuthorizationCache.ReadyForAccess)
 

pkg/image/apis/image/types.go

@@ -298,6 +298,8 @@ const (
 	ImportModePreserveOriginal ImportModeType = "PreserveOriginal"
 )
 
+var DefaultImportMode ImportModeType = ImportModeLegacy
+
 // TagReferencePolicyType describes how pull-specs for images in an image stream tag are generated when
 // image change triggers are fired.
 type TagReferencePolicyType string

pkg/image/apis/image/v1/defaults.go

@@ -5,6 +5,7 @@ import (
 
 	imagev1 "github.com/openshift/api/image/v1"
 	"github.com/openshift/library-go/pkg/image/reference"
+	apisimage "github.com/openshift/openshift-apiserver/pkg/image/apis/image"
 )
 
 func SetDefaults_ImageImportSpec(obj *imagev1.ImageImportSpec) {
@@ -25,6 +26,6 @@ func SetDefaults_TagReferencePolicy(obj *imagev1.TagReferencePolicy) {
 
 func SetDefaults_TagImportPolicy(obj *imagev1.TagImportPolicy) {
 	if len(obj.ImportMode) == 0 {
-		obj.ImportMode = imagev1.ImportModeLegacy
+		obj.ImportMode = imagev1.ImportModeType(apisimage.DefaultImportMode)
 	}
 }