Typed static/mirror pod UID translation

pkg/kubelet/kubelet_cadvisor.go

@@ -26,7 +26,9 @@ import (
 // GetContainerInfo returns stats (from Cadvisor) for a container.
 func (kl *Kubelet) GetContainerInfo(podFullName string, podUID types.UID, containerName string, req *cadvisorapi.ContainerInfoRequest) (*cadvisorapi.ContainerInfo, error) {
 
-	podUID = kl.podManager.TranslatePodUID(podUID)
+	// Resolve and type convert back again.
+	// We need the static pod UID but the kubecontainer API works with types.UID.
+	podUID = types.UID(kl.podManager.TranslatePodUID(podUID))
 
 	pods, err := kl.runtimeCache.GetPods()
 	if err != nil {

pkg/kubelet/kubelet_pods.go

@@ -1402,7 +1402,9 @@ func (kl *Kubelet) findContainer(podFullName string, podUID types.UID, container
 	if err != nil {
 		return nil, err
 	}
-	podUID = kl.podManager.TranslatePodUID(podUID)
+	// Resolve and type convert back again.
+	// We need the static pod UID but the kubecontainer API works with types.UID.
+	podUID = types.UID(kl.podManager.TranslatePodUID(podUID))
 	pod := kubecontainer.Pods(pods).FindPod(podFullName, podUID)
 	return pod.FindContainerByName(containerName), nil
 }
@@ -1468,7 +1470,9 @@ func (kl *Kubelet) PortForward(podFullName string, podUID types.UID, port int32,
 	if err != nil {
 		return err
 	}
-	podUID = kl.podManager.TranslatePodUID(podUID)
+	// Resolve and type convert back again.
+	// We need the static pod UID but the kubecontainer API works with types.UID.
+	podUID = types.UID(kl.podManager.TranslatePodUID(podUID))
 	pod := kubecontainer.Pods(pods).FindPod(podFullName, podUID)
 	if pod.IsEmpty() {
 		return fmt.Errorf("pod not found (%q)", podFullName)
@@ -1541,7 +1545,9 @@ func (kl *Kubelet) GetPortForward(podName, podNamespace string, podUID types.UID
 		if err != nil {
 			return nil, err
 		}
-		podUID = kl.podManager.TranslatePodUID(podUID)
+		// Resolve and type convert back again.
+		// We need the static pod UID but the kubecontainer API works with types.UID.
+		podUID = types.UID(kl.podManager.TranslatePodUID(podUID))
 		podFullName := kubecontainer.BuildPodFullName(podName, podNamespace)
 		pod := kubecontainer.Pods(pods).FindPod(podFullName, podUID)
 		if pod.IsEmpty() {

pkg/kubelet/pod/pod_manager.go

@@ -24,6 +24,7 @@ import (
 	"k8s.io/kubernetes/pkg/kubelet/configmap"
 	kubecontainer "k8s.io/kubernetes/pkg/kubelet/container"
 	"k8s.io/kubernetes/pkg/kubelet/secret"
+	kubetypes "k8s.io/kubernetes/pkg/kubelet/types"
 )
 
 // Manager stores and manages access to pods, maintaining the mappings
@@ -44,7 +45,7 @@ import (
 type Manager interface {
 	// GetPods returns the regular pods bound to the kubelet and their spec.
 	GetPods() []*v1.Pod
-	// GetPodByName returns the (non-mirror) pod that matches full name, as well as
+	// GetPodByFullName returns the (non-mirror) pod that matches full name, as well as
 	// whether the pod was found.
 	GetPodByFullName(podFullName string) (*v1.Pod, bool)
 	// GetPodByName provides the (non-mirror) pod that matches namespace and
@@ -83,10 +84,10 @@ type Manager interface {
 	// All public-facing functions should perform this translation for UIDs
 	// because user may provide a mirror pod UID, which is not recognized by
 	// internal Kubelet functions.
-	TranslatePodUID(uid types.UID) types.UID
+	TranslatePodUID(uid types.UID) kubetypes.ResolvedPodUID
 	// GetUIDTranslations returns the mappings of static pod UIDs to mirror pod
 	// UIDs and mirror pod UIDs to static pod UIDs.
-	GetUIDTranslations() (podToMirror, mirrorToPod map[types.UID]types.UID)
+	GetUIDTranslations() (podToMirror map[kubetypes.ResolvedPodUID]kubetypes.MirrorPodUID, mirrorToPod map[kubetypes.MirrorPodUID]kubetypes.ResolvedPodUID)
 	// IsMirrorPodOf returns true if mirrorPod is a correct representation of
 	// pod; false otherwise.
 	IsMirrorPodOf(mirrorPod, pod *v1.Pod) bool
@@ -94,7 +95,7 @@ type Manager interface {
 	MirrorClient
 }
 
-// basicManager is a functional Manger.
+// basicManager is a functional Manager.
 //
 // All fields in basicManager are read-only and are updated calling SetPods,
 // AddPod, UpdatePod, or DeletePod.
@@ -103,16 +104,16 @@ type basicManager struct {
 	lock sync.RWMutex
 
 	// Regular pods indexed by UID.
-	podByUID map[types.UID]*v1.Pod
+	podByUID map[kubetypes.ResolvedPodUID]*v1.Pod
 	// Mirror pods indexed by UID.
-	mirrorPodByUID map[types.UID]*v1.Pod
+	mirrorPodByUID map[kubetypes.MirrorPodUID]*v1.Pod
 
 	// Pods indexed by full name for easy access.
 	podByFullName       map[string]*v1.Pod
 	mirrorPodByFullName map[string]*v1.Pod
 
 	// Mirror pod UID to pod UID map.
-	translationByUID map[types.UID]types.UID
+	translationByUID map[kubetypes.MirrorPodUID]kubetypes.ResolvedPodUID
 
 	// basicManager is keeping secretManager and configMapManager up-to-date.
 	secretManager    secret.Manager
@@ -137,11 +138,11 @@ func (pm *basicManager) SetPods(newPods []*v1.Pod) {
 	pm.lock.Lock()
 	defer pm.lock.Unlock()
 
-	pm.podByUID = make(map[types.UID]*v1.Pod)
+	pm.podByUID = make(map[kubetypes.ResolvedPodUID]*v1.Pod)
 	pm.podByFullName = make(map[string]*v1.Pod)
-	pm.mirrorPodByUID = make(map[types.UID]*v1.Pod)
+	pm.mirrorPodByUID = make(map[kubetypes.MirrorPodUID]*v1.Pod)
 	pm.mirrorPodByFullName = make(map[string]*v1.Pod)
-	pm.translationByUID = make(map[types.UID]types.UID)
+	pm.translationByUID = make(map[kubetypes.MirrorPodUID]kubetypes.ResolvedPodUID)
 
 	pm.updatePodsInternal(newPods...)
 }
@@ -157,7 +158,7 @@ func (pm *basicManager) UpdatePod(pod *v1.Pod) {
 }
 
 // updatePodsInternal replaces the given pods in the current state of the
-// manager, updating the various indices.  The caller is assumed to hold the
+// manager, updating the various indices. The caller is assumed to hold the
 // lock.
 func (pm *basicManager) updatePodsInternal(pods ...*v1.Pod) {
 	for _, pod := range pods {
@@ -172,17 +173,21 @@ func (pm *basicManager) updatePodsInternal(pods ...*v1.Pod) {
 			pm.configMapManager.RegisterPod(pod)
 		}
 		podFullName := kubecontainer.GetPodFullName(pod)
+		// This logic relies on a static pod and its mirror to have the same name.
+		// It is safe to type convert here due to the IsMirrorPod guard.
 		if IsMirrorPod(pod) {
-			pm.mirrorPodByUID[pod.UID] = pod
+			mirrorPodUID := kubetypes.MirrorPodUID(pod.UID)
+			pm.mirrorPodByUID[mirrorPodUID] = pod
 			pm.mirrorPodByFullName[podFullName] = pod
 			if p, ok := pm.podByFullName[podFullName]; ok {
-				pm.translationByUID[pod.UID] = p.UID
+				pm.translationByUID[mirrorPodUID] = kubetypes.ResolvedPodUID(p.UID)
 			}
 		} else {
-			pm.podByUID[pod.UID] = pod
+			resolvedPodUID := kubetypes.ResolvedPodUID(pod.UID)
+			pm.podByUID[resolvedPodUID] = pod
 			pm.podByFullName[podFullName] = pod
 			if mirror, ok := pm.mirrorPodByFullName[podFullName]; ok {
-				pm.translationByUID[mirror.UID] = pod.UID
+				pm.translationByUID[kubetypes.MirrorPodUID(mirror.UID)] = resolvedPodUID
 			}
 		}
 	}
@@ -198,12 +203,14 @@ func (pm *basicManager) DeletePod(pod *v1.Pod) {
 		pm.configMapManager.UnregisterPod(pod)
 	}
 	podFullName := kubecontainer.GetPodFullName(pod)
+	// It is safe to type convert here due to the IsMirrorPod guard.
 	if IsMirrorPod(pod) {
-		delete(pm.mirrorPodByUID, pod.UID)
+		mirrorPodUID := kubetypes.MirrorPodUID(pod.UID)
+		delete(pm.mirrorPodByUID, mirrorPodUID)
 		delete(pm.mirrorPodByFullName, podFullName)
-		delete(pm.translationByUID, pod.UID)
+		delete(pm.translationByUID, mirrorPodUID)
 	} else {
-		delete(pm.podByUID, pod.UID)
+		delete(pm.podByUID, kubetypes.ResolvedPodUID(pod.UID))
 		delete(pm.podByFullName, podFullName)
 	}
 }
@@ -218,14 +225,14 @@ func (pm *basicManager) GetPodsAndMirrorPods() ([]*v1.Pod, []*v1.Pod) {
 	pm.lock.RLock()
 	defer pm.lock.RUnlock()
 	pods := podsMapToPods(pm.podByUID)
-	mirrorPods := podsMapToPods(pm.mirrorPodByUID)
+	mirrorPods := mirrorPodsMapToMirrorPods(pm.mirrorPodByUID)
 	return pods, mirrorPods
 }
 
 func (pm *basicManager) GetPodByUID(uid types.UID) (*v1.Pod, bool) {
 	pm.lock.RLock()
 	defer pm.lock.RUnlock()
-	pod, ok := pm.podByUID[uid]
+	pod, ok := pm.podByUID[kubetypes.ResolvedPodUID(uid)] // Safe conversion, map only holds non-mirrors.
 	return pod, ok
 }
 
@@ -241,25 +248,27 @@ func (pm *basicManager) GetPodByFullName(podFullName string) (*v1.Pod, bool) {
 	return pod, ok
 }
 
-func (pm *basicManager) TranslatePodUID(uid types.UID) types.UID {
+func (pm *basicManager) TranslatePodUID(uid types.UID) kubetypes.ResolvedPodUID {
+	// It is safe to type convert to a resolved UID because type conversion is idempotent.
 	if uid == "" {
-		return uid
+		return kubetypes.ResolvedPodUID(uid)
 	}
 
 	pm.lock.RLock()
 	defer pm.lock.RUnlock()
-	if translated, ok := pm.translationByUID[uid]; ok {
+	if translated, ok := pm.translationByUID[kubetypes.MirrorPodUID(uid)]; ok {
 		return translated
 	}
-	return uid
+	return kubetypes.ResolvedPodUID(uid)
 }
 
-func (pm *basicManager) GetUIDTranslations() (podToMirror, mirrorToPod map[types.UID]types.UID) {
+func (pm *basicManager) GetUIDTranslations() (podToMirror map[kubetypes.ResolvedPodUID]kubetypes.MirrorPodUID,
+	mirrorToPod map[kubetypes.MirrorPodUID]kubetypes.ResolvedPodUID) {
 	pm.lock.RLock()
 	defer pm.lock.RUnlock()
 
-	podToMirror = make(map[types.UID]types.UID, len(pm.translationByUID))
-	mirrorToPod = make(map[types.UID]types.UID, len(pm.translationByUID))
+	podToMirror = make(map[kubetypes.ResolvedPodUID]kubetypes.MirrorPodUID, len(pm.translationByUID))
+	mirrorToPod = make(map[kubetypes.MirrorPodUID]kubetypes.ResolvedPodUID, len(pm.translationByUID))
 	// Insert empty translation mapping for all static pods.
 	for uid, pod := range pm.podByUID {
 		if !IsStaticPod(pod) {
@@ -309,7 +318,15 @@ func (pm *basicManager) IsMirrorPodOf(mirrorPod, pod *v1.Pod) bool {
 	return hash == getPodHash(pod)
 }
 
-func podsMapToPods(UIDMap map[types.UID]*v1.Pod) []*v1.Pod {
+func podsMapToPods(UIDMap map[kubetypes.ResolvedPodUID]*v1.Pod) []*v1.Pod {
+	pods := make([]*v1.Pod, 0, len(UIDMap))
+	for _, pod := range UIDMap {
+		pods = append(pods, pod)
+	}
+	return pods
+}
+
+func mirrorPodsMapToMirrorPods(UIDMap map[kubetypes.MirrorPodUID]*v1.Pod) []*v1.Pod {
 	pods := make([]*v1.Pod, 0, len(UIDMap))
 	for _, pod := range UIDMap {
 		pods = append(pods, pod)

pkg/kubelet/pod/pod_manager_test.go

@@ -97,8 +97,8 @@ func TestGetSetPods(t *testing.T) {
 			t.Errorf("pod %q was not found in %#v", expected.UID, actualPods)
 		}
 	}
-	// Tests UID translation works as expected.
-	if uid := podManager.TranslatePodUID(mirrorPod.UID); uid != staticPod.UID {
+	// Tests UID translation works as expected. Convert static pod UID for comparison only.
+	if uid := podManager.TranslatePodUID(mirrorPod.UID); uid != kubetypes.ResolvedPodUID(staticPod.UID) {
 		t.Errorf("unable to translate UID %q to the static POD's UID %q; %#v",
 			mirrorPod.UID, staticPod.UID, podManager.mirrorPodByUID)
 	}

pkg/kubelet/status/status_manager.go

@@ -66,11 +66,11 @@ type manager struct {
 	podStatusChannel chan podStatusSyncRequest
 	// Map from (mirror) pod UID to latest status version successfully sent to the API server.
 	// apiStatusVersions must only be accessed from the sync thread.
-	apiStatusVersions map[types.UID]uint64
+	apiStatusVersions map[kubetypes.MirrorPodUID]uint64
 	podDeletionSafety PodDeletionSafetyProvider
 }
 
-// PodStatusProvider knows how to provide status for a pod.  It's intended to be used by other components
+// PodStatusProvider knows how to provide status for a pod. It's intended to be used by other components
 // that need to introspect status.
 type PodStatusProvider interface {
 	// GetPodStatus returns the cached status for the provided pod UID, as well as whether it
@@ -78,7 +78,7 @@ type PodStatusProvider interface {
 	GetPodStatus(uid types.UID) (v1.PodStatus, bool)
 }
 
-// An object which provides guarantees that a pod can be saftely deleted.
+// An object which provides guarantees that a pod can be safely deleted.
 type PodDeletionSafetyProvider interface {
 	// A function which returns true if the pod can safely be deleted
 	PodResourcesAreReclaimed(pod *v1.Pod, status v1.PodStatus) bool
@@ -116,7 +116,7 @@ func NewManager(kubeClient clientset.Interface, podManager kubepod.Manager, podD
 		podManager:        podManager,
 		podStatuses:       make(map[types.UID]versionedPodStatus),
 		podStatusChannel:  make(chan podStatusSyncRequest, 1000), // Buffer up to 1000 statuses
-		apiStatusVersions: make(map[types.UID]uint64),
+		apiStatusVersions: make(map[kubetypes.MirrorPodUID]uint64),
 		podDeletionSafety: podDeletionSafety,
 	}
 }
@@ -155,7 +155,7 @@ func (m *manager) Start() {
 func (m *manager) GetPodStatus(uid types.UID) (v1.PodStatus, bool) {
 	m.podStatusesLock.RLock()
 	defer m.podStatusesLock.RUnlock()
-	status, ok := m.podStatuses[m.podManager.TranslatePodUID(uid)]
+	status, ok := m.podStatuses[types.UID(m.podManager.TranslatePodUID(uid))]
 	return status.status, ok
 }
 
@@ -342,7 +342,7 @@ func (m *manager) updateStatusInternal(pod *v1.Pod, status v1.PodStatus, forceUp
 	default:
 		// Let the periodic syncBatch handle the update if the channel is full.
 		// We can't block, since we hold the mutex lock.
-		glog.V(4).Infof("Skpping the status update for pod %q for now because the channel is full; status: %+v",
+		glog.V(4).Infof("Skipping the status update for pod %q for now because the channel is full; status: %+v",
 			format.Pod(pod), status)
 		return false
 	}
@@ -377,7 +377,7 @@ func (m *manager) syncBatch() {
 
 		// Clean up orphaned versions.
 		for uid := range m.apiStatusVersions {
-			_, hasPod := m.podStatuses[uid]
+			_, hasPod := m.podStatuses[types.UID(uid)]
 			_, hasMirror := mirrorToPod[uid]
 			if !hasPod && !hasMirror {
 				delete(m.apiStatusVersions, uid)
@@ -385,15 +385,15 @@ func (m *manager) syncBatch() {
 		}
 
 		for uid, status := range m.podStatuses {
-			syncedUID := uid
-			if mirrorUID, ok := podToMirror[uid]; ok {
+			syncedUID := kubetypes.MirrorPodUID(uid)
+			if mirrorUID, ok := podToMirror[kubetypes.ResolvedPodUID(uid)]; ok {
 				if mirrorUID == "" {
 					glog.V(5).Infof("Static pod %q (%s/%s) does not have a corresponding mirror pod; skipping", uid, status.podName, status.podNamespace)
 					continue
 				}
 				syncedUID = mirrorUID
 			}
-			if m.needsUpdate(syncedUID, status) {
+			if m.needsUpdate(types.UID(syncedUID), status) {
 				updatedStatuses = append(updatedStatuses, podStatusSyncRequest{uid, status})
 			} else if m.needsReconcile(uid, status.status) {
 				// Delete the apiStatusVersions here to force an update on the pod status
@@ -433,7 +433,8 @@ func (m *manager) syncPod(uid types.UID, status versionedPodStatus) {
 	}
 
 	translatedUID := m.podManager.TranslatePodUID(pod.UID)
-	if len(translatedUID) > 0 && translatedUID != uid {
+	// Type convert original uid just for the purpose of comparison.
+	if len(translatedUID) > 0 && translatedUID != kubetypes.ResolvedPodUID(uid) {
 		glog.V(2).Infof("Pod %q was deleted and then recreated, skipping status update; old UID %q, new UID %q", format.Pod(pod), uid, translatedUID)
 		m.deletePodStatus(uid)
 		return
@@ -451,7 +452,7 @@ func (m *manager) syncPod(uid types.UID, status versionedPodStatus) {
 	pod = newPod
 
 	glog.V(3).Infof("Status for pod %q updated successfully: (%d, %+v)", format.Pod(pod), status.version, status.status)
-	m.apiStatusVersions[pod.UID] = status.version
+	m.apiStatusVersions[kubetypes.MirrorPodUID(pod.UID)] = status.version
 
 	// We don't handle graceful deletion of mirror pods.
 	if m.canBeDeleted(pod, status.status) {
@@ -469,9 +470,9 @@ func (m *manager) syncPod(uid types.UID, status versionedPodStatus) {
 }
 
 // needsUpdate returns whether the status is stale for the given pod UID.
-// This method is not thread safe, and most only be accessed by the sync thread.
+// This method is not thread safe, and must only be accessed by the sync thread.
 func (m *manager) needsUpdate(uid types.UID, status versionedPodStatus) bool {
-	latest, ok := m.apiStatusVersions[uid]
+	latest, ok := m.apiStatusVersions[kubetypes.MirrorPodUID(uid)]
 	if !ok || latest < status.version {
 		return true
 	}

pkg/kubelet/status/status_manager_test.go

@@ -401,7 +401,8 @@ func TestStaleUpdates(t *testing.T) {
 	verifyUpdates(t, m, 0)
 
 	t.Log("... unless it's stale.")
-	m.apiStatusVersions[pod.UID] = m.apiStatusVersions[pod.UID] - 1
+	mirrorPodUID := kubetypes.MirrorPodUID(pod.UID)
+	m.apiStatusVersions[mirrorPodUID] = m.apiStatusVersions[mirrorPodUID] - 1
 
 	m.SetPodStatus(pod, status)
 	m.syncBatch()
@@ -515,7 +516,7 @@ func TestStaticPod(t *testing.T) {
 	t.Logf("Create the mirror pod")
 	m.podManager.AddPod(mirrorPod)
 	assert.True(t, kubepod.IsMirrorPod(mirrorPod), "SetUp error: mirrorPod")
-	assert.Equal(t, m.podManager.TranslatePodUID(mirrorPod.UID), staticPod.UID)
+	assert.Equal(t, m.podManager.TranslatePodUID(mirrorPod.UID), kubetypes.ResolvedPodUID(staticPod.UID))
 
 	t.Logf("Should be able to get the mirror pod status from status manager")
 	retrievedStatus, _ = m.GetPodStatus(mirrorPod.UID)
@@ -668,13 +669,13 @@ func TestSyncBatchCleanupVersions(t *testing.T) {
 	}
 
 	t.Logf("Orphaned pods should be removed.")
-	m.apiStatusVersions[testPod.UID] = 100
-	m.apiStatusVersions[mirrorPod.UID] = 200
+	m.apiStatusVersions[kubetypes.MirrorPodUID(testPod.UID)] = 100
+	m.apiStatusVersions[kubetypes.MirrorPodUID(mirrorPod.UID)] = 200
 	m.syncBatch()
-	if _, ok := m.apiStatusVersions[testPod.UID]; ok {
+	if _, ok := m.apiStatusVersions[kubetypes.MirrorPodUID(testPod.UID)]; ok {
 		t.Errorf("Should have cleared status for testPod")
 	}
-	if _, ok := m.apiStatusVersions[mirrorPod.UID]; ok {
+	if _, ok := m.apiStatusVersions[kubetypes.MirrorPodUID(mirrorPod.UID)]; ok {
 		t.Errorf("Should have cleared status for mirrorPod")
 	}
 
@@ -685,13 +686,13 @@ func TestSyncBatchCleanupVersions(t *testing.T) {
 	staticPod.UID = "static-uid"
 	staticPod.Annotations = map[string]string{kubetypes.ConfigSourceAnnotationKey: "file"}
 	m.podManager.AddPod(staticPod)
-	m.apiStatusVersions[testPod.UID] = 100
-	m.apiStatusVersions[mirrorPod.UID] = 200
+	m.apiStatusVersions[kubetypes.MirrorPodUID(testPod.UID)] = 100
+	m.apiStatusVersions[kubetypes.MirrorPodUID(mirrorPod.UID)] = 200
 	m.testSyncBatch()
-	if _, ok := m.apiStatusVersions[testPod.UID]; !ok {
+	if _, ok := m.apiStatusVersions[kubetypes.MirrorPodUID(testPod.UID)]; !ok {
 		t.Errorf("Should not have cleared status for testPod")
 	}
-	if _, ok := m.apiStatusVersions[mirrorPod.UID]; !ok {
+	if _, ok := m.apiStatusVersions[kubetypes.MirrorPodUID(mirrorPod.UID)]; !ok {
 		t.Errorf("Should not have cleared status for mirrorPod")
 	}
 }
@@ -786,7 +787,7 @@ func TestDoNotDeleteMirrorPods(t *testing.T) {
 	t.Logf("Verify setup.")
 	assert.True(t, kubepod.IsStaticPod(staticPod), "SetUp error: staticPod")
 	assert.True(t, kubepod.IsMirrorPod(mirrorPod), "SetUp error: mirrorPod")
-	assert.Equal(t, m.podManager.TranslatePodUID(mirrorPod.UID), staticPod.UID)
+	assert.Equal(t, m.podManager.TranslatePodUID(mirrorPod.UID), kubetypes.ResolvedPodUID(staticPod.UID))
 
 	status := getRandomPodStatus()
 	now := metav1.Now()

pkg/kubelet/types/BUILD

@@ -19,6 +19,7 @@ go_library(
         "//pkg/api:go_default_library",
         "//vendor/k8s.io/api/core/v1:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/apis/meta/v1:go_default_library",
+        "//vendor/k8s.io/apimachinery/pkg/types:go_default_library",
     ],
 )
 

pkg/kubelet/types/types.go

@@ -21,6 +21,7 @@ import (
 	"time"
 
 	"k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/types"
 )
 
 // TODO: Reconcile custom types in kubelet/types and this subpackage
@@ -91,3 +92,9 @@ type Reservation struct {
 	// Kubernetes represents resources reserved for kubernetes system components.
 	Kubernetes v1.ResourceList
 }
+
+// A pod UID which has been translated/resolved to the representation known to kubelets.
+type ResolvedPodUID types.UID
+
+// A pod UID for a mirror pod.
+type MirrorPodUID types.UID