UPSTREAM: <carry>: openshift KCM volume plugin manager uses a disjoint set of featuregates

The volume plugin manager for openshfit's Attach Detach controller in
kube-controller-manager uses a set of featuregates that are NOT the same as
the the other controllers in KCM and the kubelet.

This means these featuregates (if we kept the old names) would be
inconsistent inside of a single binary. There are now separate featuregates
for the volumepluginmanger when running in the Attach Detach controller to
reflect this distintion.

See openshift/enhancements#549 for details.

Stop <carrying> the patch when CSI migration becomes GA (i.e.
features.CSIMigrationAWS / features.CSIMigrationOpenStack are GA).

Author: jsafrane

pkg/controller/volume/attachdetach/attach_detach_controller.go

@@ -184,7 +184,7 @@ func NewAttachDetachController(
 
 	csiTranslator := csitrans.New()
 	adc.intreeToCSITranslator = csiTranslator
-	adc.csiMigratedPluginManager = csimigration.NewPluginManager(csiTranslator, utilfeature.DefaultFeatureGate)
+	adc.csiMigratedPluginManager = csimigration.NewADCPluginManager(csiTranslator, utilfeature.DefaultFeatureGate)
 
 	adc.desiredStateOfWorldPopulator = populator.NewDesiredStateOfWorldPopulator(
 		timerConfig.DesiredStateOfWorldPopulatorLoopSleepPeriod,

pkg/features/patch_kube_features.go

@@ -0,0 +1,30 @@
+package features
+
+import (
+	"k8s.io/apimachinery/pkg/util/runtime"
+	utilfeature "k8s.io/apiserver/pkg/util/feature"
+	"k8s.io/component-base/featuregate"
+)
+
+var (
+	// owner: @jsafrane
+	// alpha: v1.21
+	//
+	// Enables the AWS EBS CSI migration for the Attach/Detach controller (ADC) only.
+	ADCCSIMigrationAWS featuregate.Feature = "ADC_CSIMigrationAWS"
+
+	// owner: @jsafrane
+	// alpha: v1.21
+	//
+	// Enables the Cinder CSI migration for the Attach/Detach controller (ADC) only.
+	ADCCSIMigrationCinder featuregate.Feature = "ADC_CSIMigrationCinder"
+)
+
+var ocpDefaultKubernetesFeatureGates = map[featuregate.Feature]featuregate.FeatureSpec{
+	ADCCSIMigrationAWS:    {Default: true, PreRelease: featuregate.Beta},
+	ADCCSIMigrationCinder: {Default: true, PreRelease: featuregate.Beta},
+}
+
+func init() {
+	runtime.Must(utilfeature.DefaultMutableFeatureGate.Add(ocpDefaultKubernetesFeatureGates))
+}

pkg/volume/csimigration/patch_adc_plugin_manager.go

@@ -0,0 +1,44 @@
+package csimigration
+
+import (
+	"k8s.io/component-base/featuregate"
+	csilibplugins "k8s.io/csi-translation-lib/plugins"
+	"k8s.io/kubernetes/pkg/features"
+)
+
+// NewADCPluginManager returns a new PluginManager instance for the Attach Detach controller which uses different
+// featuregates in openshift to control enablement/disablement which *DO NOT MATCH* the featuregates for the rest of the
+// cluster.
+func NewADCPluginManager(m PluginNameMapper, featureGate featuregate.FeatureGate) PluginManager {
+	ret := NewPluginManager(m, featureGate)
+	ret.useADCPluginManagerFeatureGates = true
+	return ret
+}
+
+// adcIsMigrationEnabledForPlugin indicates whether CSI migration has been enabled
+// for a particular storage plugin in Attach/Detach controller.
+func (pm PluginManager) adcIsMigrationEnabledForPlugin(pluginName string) bool {
+	// CSIMigration feature should be enabled along with the plugin-specific one
+	if !pm.featureGate.Enabled(features.CSIMigration) {
+		return false
+	}
+
+	switch pluginName {
+	case csilibplugins.AWSEBSInTreePluginName:
+		return pm.featureGate.Enabled(features.ADCCSIMigrationAWS)
+	case csilibplugins.CinderInTreePluginName:
+		return pm.featureGate.Enabled(features.ADCCSIMigrationCinder)
+	default:
+		return pm.isMigrationEnabledForPlugin(pluginName)
+	}
+}
+
+// IsMigrationEnabledForPlugin indicates whether CSI migration has been enabled
+// for a particular storage plugin
+func (pm PluginManager) IsMigrationEnabledForPlugin(pluginName string) bool {
+	if pm.useADCPluginManagerFeatureGates {
+		return pm.adcIsMigrationEnabledForPlugin(pluginName)
+	}
+
+	return pm.isMigrationEnabledForPlugin(pluginName)
+}

pkg/volume/csimigration/plugin_manager.go

@@ -38,6 +38,8 @@ type PluginNameMapper interface {
 type PluginManager struct {
 	PluginNameMapper
 	featureGate featuregate.FeatureGate
+
+	useADCPluginManagerFeatureGates bool
 }
 
 // NewPluginManager returns a new PluginManager instance
@@ -77,9 +79,7 @@ func (pm PluginManager) IsMigrationCompleteForPlugin(pluginName string) bool {
 	}
 }
 
-// IsMigrationEnabledForPlugin indicates whether CSI migration has been enabled
-// for a particular storage plugin
-func (pm PluginManager) IsMigrationEnabledForPlugin(pluginName string) bool {
+func (pm PluginManager) isMigrationEnabledForPlugin(pluginName string) bool {
 	// CSIMigration feature should be enabled along with the plugin-specific one
 	if !pm.featureGate.Enabled(features.CSIMigration) {
 		return false