added a comment that statuses lists are not being validated

pkg/apis/core/types.go

@@ -4106,16 +4106,37 @@ type PodStatus struct {
 	// +optional
 	QOSClass PodQOSClass
 
-	// The list has one entry per init container in the manifest. The most recent successful
+	// Statuses of init containers in this pod. The most recent successful non-restartable
 	// init container will have ready = true, the most recently started container will have
 	// startTime set.
+	// Each init container in the pod should have at most one status in this list,
+	// and all statuses should be for containers in the pod.
+	// However this is not enforced.
+	// If a status for a non-existent container is present in the list, or the list has duplicate names,
+	// the behavior of various Kubernetes components is not defined and those statuses might be
+	// ignored.
 	// More info: https://kubernetes.io/docs/concepts/workloads/pods/pod-lifecycle/#pod-and-container-status
 	InitContainerStatuses []ContainerStatus
-	// The list has one entry per app container in the manifest.
+
+	// Statuses of containers in this pod.
+	// Each container in the pod should have at most one status in this list,
+	// and all statuses should be for containers in the pod.
+	// However this is not enforced.
+	// If a status for a non-existent container is present in the list, or the list has duplicate names,
+	// the behavior of various Kubernetes components is not defined and those statuses might be
+	// ignored.
+	// More info: https://kubernetes.io/docs/concepts/workloads/pods/pod-lifecycle#pod-and-container-status
 	// +optional
 	ContainerStatuses []ContainerStatus
 
-	// Status for any ephemeral containers that have run in this pod.
+	// Statuses for any ephemeral containers that have run in this pod.
+	// Each ephemeral container in the pod should have at most one status in this list,
+	// and all statuses should be for containers in the pod.
+	// However this is not enforced.
+	// If a status for a non-existent container is present in the list, or the list has duplicate names,
+	// the behavior of various Kubernetes components is not defined and those statuses might be
+	// ignored.
+	// More info: https://kubernetes.io/docs/concepts/workloads/pods/pod-lifecycle#pod-and-container-status
 	// +optional
 	EphemeralContainerStatuses []ContainerStatus
 

pkg/apis/core/validation/validation.go

@@ -5385,6 +5385,10 @@ func ValidatePodStatusUpdate(newPod, oldPod *core.Pod, opts PodValidationOptions
 	// Pod QoS is immutable
 	allErrs = append(allErrs, ValidateImmutableField(newPod.Status.QOSClass, oldPod.Status.QOSClass, fldPath.Child("qosClass"))...)
 
+	// Note: there is no check that ContainerStatuses, InitContainerStatuses, and EphemeralContainerStatuses doesn't have duplicate conatainer names
+	// or statuses of containers that are not defined in the pod spec. Changing this may lead to a breaking changes. So consumers of those fields
+	// must account for unexpected data. Kubelet will never report statuses like this.
+	//
 	// If pod should not restart, make sure the status update does not transition
 	// any terminated containers to a non-terminated state.
 	allErrs = append(allErrs, ValidateContainerStateTransition(newPod.Status.ContainerStatuses, oldPod.Status.ContainerStatuses, fldPath.Child("containerStatuses"), oldPod.Spec.RestartPolicy)...)

pkg/kubelet/types/types.go

@@ -72,7 +72,8 @@ func (s SortedContainerStatuses) Less(i, j int) bool {
 }
 
 // SortInitContainerStatuses ensures that statuses are in the order that their
-// init container appears in the pod spec
+// init container appears in the pod spec. The function assumes there are no
+// duplicate names in the statuses.
 func SortInitContainerStatuses(p *v1.Pod, statuses []v1.ContainerStatus) {
 	containers := p.Spec.InitContainers
 	current := 0

staging/src/k8s.io/api/core/v1/types.go

@@ -4809,24 +4809,45 @@ type PodStatus struct {
 	// +optional
 	StartTime *metav1.Time `json:"startTime,omitempty" protobuf:"bytes,7,opt,name=startTime"`
 
-	// The list has one entry per init container in the manifest. The most recent successful
+	// Statuses of init containers in this pod. The most recent successful non-restartable
 	// init container will have ready = true, the most recently started container will have
 	// startTime set.
-	// More info: https://kubernetes.io/docs/concepts/workloads/pods/pod-lifecycle#pod-and-container-status
+	// Each init container in the pod should have at most one status in this list,
+	// and all statuses should be for containers in the pod.
+	// However this is not enforced.
+	// If a status for a non-existent container is present in the list, or the list has duplicate names,
+	// the behavior of various Kubernetes components is not defined and those statuses might be
+	// ignored.
+	// More info: https://kubernetes.io/docs/concepts/workloads/pods/pod-lifecycle/#pod-and-container-status
 	// +listType=atomic
 	InitContainerStatuses []ContainerStatus `json:"initContainerStatuses,omitempty" protobuf:"bytes,10,rep,name=initContainerStatuses"`
 
-	// The list has one entry per container in the manifest.
+	// Statuses of containers in this pod.
+	// Each container in the pod should have at most one status in this list,
+	// and all statuses should be for containers in the pod.
+	// However this is not enforced.
+	// If a status for a non-existent container is present in the list, or the list has duplicate names,
+	// the behavior of various Kubernetes components is not defined and those statuses might be
+	// ignored.
 	// More info: https://kubernetes.io/docs/concepts/workloads/pods/pod-lifecycle#pod-and-container-status
 	// +optional
 	// +listType=atomic
 	ContainerStatuses []ContainerStatus `json:"containerStatuses,omitempty" protobuf:"bytes,8,rep,name=containerStatuses"`
+
 	// The Quality of Service (QOS) classification assigned to the pod based on resource requirements
 	// See PodQOSClass type for available QOS classes
 	// More info: https://kubernetes.io/docs/concepts/workloads/pods/pod-qos/#quality-of-service-classes
 	// +optional
 	QOSClass PodQOSClass `json:"qosClass,omitempty" protobuf:"bytes,9,rep,name=qosClass"`
-	// Status for any ephemeral containers that have run in this pod.
+
+	// Statuses for any ephemeral containers that have run in this pod.
+	// Each ephemeral container in the pod should have at most one status in this list,
+	// and all statuses should be for containers in the pod.
+	// However this is not enforced.
+	// If a status for a non-existent container is present in the list, or the list has duplicate names,
+	// the behavior of various Kubernetes components is not defined and those statuses might be
+	// ignored.
+	// More info: https://kubernetes.io/docs/concepts/workloads/pods/pod-lifecycle#pod-and-container-status
 	// +optional
 	// +listType=atomic
 	EphemeralContainerStatuses []ContainerStatus `json:"ephemeralContainerStatuses,omitempty" protobuf:"bytes,13,rep,name=ephemeralContainerStatuses"`