node: devicemgr: Remove devicePluginEnabled field from container mgr

With graduation of device plugins to GA in 1.26, the feature gate is
enabled by default so `devicePluginEnabled` field no longer needs to
be passed at the time of Container Manager creation.

In addition to that, we remove the `ManagerStub` as it is no longer
needed.

Signed-off-by: Swati Sehgal <swsehgal@redhat.com>

cmd/kubelet/app/server.go

@@ -704,8 +704,6 @@ func run(ctx context.Context, s *options.KubeletServer, kubeDeps *kubelet.Depend
 			return err
 		}
 
-		devicePluginEnabled := utilfeature.DefaultFeatureGate.Enabled(features.DevicePlugins)
-
 		var cpuManagerPolicyOptions map[string]string
 		if utilfeature.DefaultFeatureGate.Enabled(features.CPUManager) {
 			if utilfeature.DefaultFeatureGate.Enabled(features.CPUManagerPolicyOptions) {
@@ -751,7 +749,6 @@ func run(ctx context.Context, s *options.KubeletServer, kubeDeps *kubelet.Depend
 				ExperimentalTopologyManagerScope:        s.TopologyManagerScope,
 			},
 			s.FailSwapOn,
-			devicePluginEnabled,
 			kubeDeps.Recorder)
 
 		if err != nil {

pkg/kubelet/cm/container_manager_linux.go

@@ -194,7 +194,7 @@ func validateSystemRequirements(mountUtil mount.Interface) (features, error) {
 // TODO(vmarmol): Add limits to the system containers.
 // Takes the absolute name of the specified containers.
 // Empty container name disables use of the specified container.
-func NewContainerManager(mountUtil mount.Interface, cadvisorInterface cadvisor.Interface, nodeConfig NodeConfig, failSwapOn bool, devicePluginEnabled bool, recorder record.EventRecorder) (ContainerManager, error) {
+func NewContainerManager(mountUtil mount.Interface, cadvisorInterface cadvisor.Interface, nodeConfig NodeConfig, failSwapOn bool, recorder record.EventRecorder) (ContainerManager, error) {
 	subsystems, err := GetCgroupSubsystems()
 	if err != nil {
 		return nil, fmt.Errorf("failed to get mounted cgroup subsystems: %v", err)
@@ -298,16 +298,12 @@ func NewContainerManager(mountUtil mount.Interface, cadvisorInterface cadvisor.I
 		cm.topologyManager = topologymanager.NewFakeManager()
 	}
 
-	klog.InfoS("Creating device plugin manager", "devicePluginEnabled", devicePluginEnabled)
+	klog.InfoS("Creating device plugin manager")
-	if devicePluginEnabled {
+	cm.deviceManager, err = devicemanager.NewManagerImpl(machineInfo.Topology, cm.topologyManager)
-		cm.deviceManager, err = devicemanager.NewManagerImpl(machineInfo.Topology, cm.topologyManager)
-		cm.topologyManager.AddHintProvider(cm.deviceManager)
-	} else {
-		cm.deviceManager, err = devicemanager.NewManagerStub()
-	}
 	if err != nil {
 		return nil, err
 	}
+	cm.topologyManager.AddHintProvider(cm.deviceManager)
 
 	// Initialize CPU manager
 	if utilfeature.DefaultFeatureGate.Enabled(kubefeatures.CPUManager) {

pkg/kubelet/cm/container_manager_unsupported.go

@@ -42,6 +42,6 @@ func (unsupportedContainerManager) Start(_ *v1.Node, _ ActivePodsFunc, _ config.
 	return fmt.Errorf("Container Manager is unsupported in this build")
 }
 
-func NewContainerManager(_ mount.Interface, _ cadvisor.Interface, _ NodeConfig, failSwapOn bool, devicePluginEnabled bool, recorder record.EventRecorder) (ContainerManager, error) {
+func NewContainerManager(_ mount.Interface, _ cadvisor.Interface, _ NodeConfig, failSwapOn bool, recorder record.EventRecorder) (ContainerManager, error) {
 	return &unsupportedContainerManager{}, nil
 }

pkg/kubelet/cm/container_manager_windows.go

@@ -93,7 +93,7 @@ func (cm *containerManagerImpl) Start(node *v1.Node,
 }
 
 // NewContainerManager creates windows container manager.
-func NewContainerManager(mountUtil mount.Interface, cadvisorInterface cadvisor.Interface, nodeConfig NodeConfig, failSwapOn bool, devicePluginEnabled bool, recorder record.EventRecorder) (ContainerManager, error) {
+func NewContainerManager(mountUtil mount.Interface, cadvisorInterface cadvisor.Interface, nodeConfig NodeConfig, failSwapOn bool, recorder record.EventRecorder) (ContainerManager, error) {
 	// It is safe to invoke `MachineInfo` on cAdvisor before logically initializing cAdvisor here because
 	// machine info is computed and cached once as part of cAdvisor object creation.
 	// But `RootFsInfo` and `ImagesFsInfo` are not available at this moment so they will be called later during manager starts
@@ -111,16 +111,12 @@ func NewContainerManager(mountUtil mount.Interface, cadvisorInterface cadvisor.I
 
 	cm.topologyManager = topologymanager.NewFakeManager()
 
-	klog.InfoS("Creating device plugin manager", "devicePluginEnabled", devicePluginEnabled)
+	klog.InfoS("Creating device plugin manager")
-	if devicePluginEnabled {
+	cm.deviceManager, err = devicemanager.NewManagerImpl(nil, cm.topologyManager)
-		cm.deviceManager, err = devicemanager.NewManagerImpl(nil, cm.topologyManager)
-		cm.topologyManager.AddHintProvider(cm.deviceManager)
-	} else {
-		cm.deviceManager, err = devicemanager.NewManagerStub()
-	}
 	if err != nil {
 		return nil, err
 	}
+	cm.topologyManager.AddHintProvider(cm.deviceManager)
 
 	return cm, nil
 }

pkg/kubelet/cm/devicemanager/manager_stub.go

@@ -1,99 +0,0 @@
-/*
-Copyright 2017 The Kubernetes Authors.
-
-Licensed under the Apache License, Version 2.0 (the "License");
-you may not use this file except in compliance with the License.
-You may obtain a copy of the License at
-
-    http://www.apache.org/licenses/LICENSE-2.0
-
-Unless required by applicable law or agreed to in writing, software
-distributed under the License is distributed on an "AS IS" BASIS,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.
-*/
-
-package devicemanager
-
-import (
-	v1 "k8s.io/api/core/v1"
-	"k8s.io/kubernetes/pkg/kubelet/cm/topologymanager"
-	"k8s.io/kubernetes/pkg/kubelet/config"
-	"k8s.io/kubernetes/pkg/kubelet/lifecycle"
-	"k8s.io/kubernetes/pkg/kubelet/pluginmanager/cache"
-	schedulerframework "k8s.io/kubernetes/pkg/scheduler/framework"
-)
-
-// ManagerStub provides a simple stub implementation for the Device Manager.
-type ManagerStub struct{}
-
-// NewManagerStub creates a ManagerStub.
-func NewManagerStub() (*ManagerStub, error) {
-	return &ManagerStub{}, nil
-}
-
-// Start simply returns nil.
-func (h *ManagerStub) Start(activePods ActivePodsFunc, sourcesReady config.SourcesReady) error {
-	return nil
-}
-
-// Stop simply returns nil.
-func (h *ManagerStub) Stop() error {
-	return nil
-}
-
-// Allocate simply returns nil.
-func (h *ManagerStub) Allocate(pod *v1.Pod, container *v1.Container) error {
-	return nil
-}
-
-// UpdatePluginResources simply returns nil.
-func (h *ManagerStub) UpdatePluginResources(node *schedulerframework.NodeInfo, attrs *lifecycle.PodAdmitAttributes) error {
-	return nil
-}
-
-// GetDeviceRunContainerOptions simply returns nil.
-func (h *ManagerStub) GetDeviceRunContainerOptions(pod *v1.Pod, container *v1.Container) (*DeviceRunContainerOptions, error) {
-	return nil, nil
-}
-
-// GetCapacity simply returns nil capacity and empty removed resource list.
-func (h *ManagerStub) GetCapacity() (v1.ResourceList, v1.ResourceList, []string) {
-	return nil, nil, []string{}
-}
-
-// GetWatcherHandler returns plugin watcher interface
-func (h *ManagerStub) GetWatcherHandler() cache.PluginHandler {
-	return nil
-}
-
-// GetTopologyHints returns an empty TopologyHint map
-func (h *ManagerStub) GetTopologyHints(pod *v1.Pod, container *v1.Container) map[string][]topologymanager.TopologyHint {
-	return map[string][]topologymanager.TopologyHint{}
-}
-
-// GetPodTopologyHints returns an empty TopologyHint map
-func (h *ManagerStub) GetPodTopologyHints(pod *v1.Pod) map[string][]topologymanager.TopologyHint {
-	return map[string][]topologymanager.TopologyHint{}
-}
-
-// GetDevices returns nil
-func (h *ManagerStub) GetDevices(_, _ string) ResourceDeviceInstances {
-	return nil
-}
-
-// GetAllocatableDevices returns nothing
-func (h *ManagerStub) GetAllocatableDevices() ResourceDeviceInstances {
-	return nil
-}
-
-// ShouldResetExtendedResourceCapacity returns false
-func (h *ManagerStub) ShouldResetExtendedResourceCapacity() bool {
-	return false
-}
-
-// UpdateAllocatedDevices returns nothing
-func (h *ManagerStub) UpdateAllocatedDevices() {
-	return
-}