Change GetTopologyPodAdmitHandler() to be more general

GetTopologyPodAdmitHandler() now returns a lifecycle.PodAdmitHandler
type instead of the TopologyManager directly. The handler it returns
is generally responsible for attempting to allocate any resources that
require a pod admission check. When the TopologyManager feature gate
is on, this comes directly from the TopologyManager. When it is off,
we simply attempt the allocations ourselves and fail the admission
on an unexpected error. The higher level kubelet.go feature gate
check will be removed in an upcoming PR.

pkg/kubelet/cm/container_manager.go

@@ -25,7 +25,6 @@ import (
 	internalapi "k8s.io/cri-api/pkg/apis"
 	podresourcesapi "k8s.io/kubernetes/pkg/kubelet/apis/podresources/v1alpha1"
 	"k8s.io/kubernetes/pkg/kubelet/cm/cpuset"
-	"k8s.io/kubernetes/pkg/kubelet/cm/topologymanager"
 	"k8s.io/kubernetes/pkg/kubelet/config"
 	kubecontainer "k8s.io/kubernetes/pkg/kubelet/container"
 	evictionapi "k8s.io/kubernetes/pkg/kubelet/eviction/api"
@@ -111,8 +110,8 @@ type ContainerManager interface {
 	// due to node recreation.
 	ShouldResetExtendedResourceCapacity() bool
 
-	// GetTopologyPodAdmitHandler returns an instance of the TopologyManager for Pod Admission
-	GetTopologyPodAdmitHandler() topologymanager.Manager
+	// GetTopologyPodAdmitHandler returns an instance of a PodAdmitHandler responsible for allocating pod resources.
+	GetTopologyPodAdmitHandler() lifecycle.PodAdmitHandler
 
 	// UpdateAllocatedDevices frees any Devices that are bound to terminated pods.
 	UpdateAllocatedDevices()

pkg/kubelet/cm/container_manager_linux.go

@@ -672,15 +672,51 @@ func (cm *containerManagerImpl) GetResources(pod *v1.Pod, container *v1.Containe
 }
 
 func (cm *containerManagerImpl) UpdatePluginResources(node *schedulernodeinfo.NodeInfo, attrs *lifecycle.PodAdmitAttributes) error {
-	err := cm.deviceManager.Allocate(attrs.Pod)
-	if err != nil {
-		return err
-	}
 	return cm.deviceManager.UpdatePluginResources(node, attrs)
 }
 
-func (cm *containerManagerImpl) GetTopologyPodAdmitHandler() topologymanager.Manager {
-	return cm.topologyManager
+func (cm *containerManagerImpl) GetTopologyPodAdmitHandler() lifecycle.PodAdmitHandler {
+	if utilfeature.DefaultFeatureGate.Enabled(kubefeatures.TopologyManager) {
+		return cm.topologyManager
+	}
+	// TODO: we need to think about a better way to do this. This will work for
+	// now so long as we have only the cpuManager and deviceManager relying on
+	// allocations here. However, going forward it is not generalized enough to
+	// work as we add more and more hint providers that the TopologyManager
+	// needs to call Allocate() on (that may not be directly intstantiated
+	// inside this component).
+	return &resourceAllocator{cm.cpuManager, cm.deviceManager}
+}
+
+type resourceAllocator struct {
+	cpuManager    cpumanager.Manager
+	deviceManager devicemanager.Manager
+}
+
+func (m *resourceAllocator) Admit(attrs *lifecycle.PodAdmitAttributes) lifecycle.PodAdmitResult {
+	pod := attrs.Pod
+
+	for _, container := range append(pod.Spec.InitContainers, pod.Spec.Containers...) {
+		err := m.deviceManager.Allocate(pod, &container)
+		if err != nil {
+			return lifecycle.PodAdmitResult{
+				Message: fmt.Sprintf("Allocate failed due to %v, which is unexpected", err),
+				Reason:  "UnexpectedAdmissionError",
+				Admit:   false,
+			}
+		}
+
+		err = m.cpuManager.Allocate(pod, &container)
+		if err != nil {
+			return lifecycle.PodAdmitResult{
+				Message: fmt.Sprintf("Allocate failed due to %v, which is unexpected", err),
+				Reason:  "UnexpectedAdmissionError",
+				Admit:   false,
+			}
+		}
+	}
+
+	return lifecycle.PodAdmitResult{Admit: true}
 }
 
 func (cm *containerManagerImpl) SystemCgroupsLimit() v1.ResourceList {

pkg/kubelet/cm/container_manager_stub.go

@@ -117,8 +117,8 @@ func (cm *containerManagerStub) ShouldResetExtendedResourceCapacity() bool {
 	return cm.shouldResetExtendedResourceCapacity
 }
 
-func (cm *containerManagerStub) GetTopologyPodAdmitHandler() topologymanager.Manager {
-	return nil
+func (cm *containerManagerStub) GetTopologyPodAdmitHandler() lifecycle.PodAdmitHandler {
+	return topologymanager.NewFakeManager()
 }
 
 func (cm *containerManagerStub) UpdateAllocatedDevices() {

pkg/kubelet/cm/container_manager_windows.go

@@ -178,7 +178,7 @@ func (cm *containerManagerImpl) ShouldResetExtendedResourceCapacity() bool {
 	return false
 }
 
-func (cm *containerManagerImpl) GetTopologyPodAdmitHandler() topologymanager.Manager {
+func (cm *containerManagerImpl) GetTopologyPodAdmitHandler() lifecycle.PodAdmitHandler {
 	return nil
 }