Process only CPU and memory stats when Kubelete stats API is called with

only_cpu_and_memory parameter. Before all stats were processed and
removed before returning.

pkg/kubelet/server/stats/summary.go

@@ -91,30 +91,33 @@ func (sp *summaryProviderImpl) Get(updateStats bool) (*statsapi.Summary, error)
 }
 
 func (sp *summaryProviderImpl) GetCPUAndMemoryStats() (*statsapi.Summary, error) {
-	summary, err := sp.Get(false)
+	// TODO(timstclair): Consider returning a best-effort response if any of
+	// the following errors occur.
+	node, err := sp.provider.GetNode()
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("failed to get node info: %v", err)
 	}
-	summary.Node.Network = nil
-	summary.Node.Fs = nil
-	summary.Node.Runtime = nil
-	summary.Node.Rlimit = nil
-	for i := 0; i < len(summary.Node.SystemContainers); i++ {
-		summary.Node.SystemContainers[i].Accelerators = nil
-		summary.Node.SystemContainers[i].Rootfs = nil
-		summary.Node.SystemContainers[i].Logs = nil
-		summary.Node.SystemContainers[i].UserDefinedMetrics = nil
+	nodeConfig := sp.provider.GetNodeConfig()
+	rootStats, err := sp.provider.GetCgroupCPUAndMemoryStats("/", false)
+	if err != nil {
+		return nil, fmt.Errorf("failed to get root cgroup stats: %v", err)
 	}
-	for i := 0; i < len(summary.Pods); i++ {
-		summary.Pods[i].Network = nil
-		summary.Pods[i].VolumeStats = nil
-		summary.Pods[i].EphemeralStorage = nil
-		for j := 0; j < len(summary.Pods[i].Containers); j++ {
-			summary.Pods[i].Containers[j].Accelerators = nil
-			summary.Pods[i].Containers[j].Rootfs = nil
-			summary.Pods[i].Containers[j].Logs = nil
-			summary.Pods[i].Containers[j].UserDefinedMetrics = nil
-		}
+
+	podStats, err := sp.provider.ListPodCPUAndMemoryStats()
+	if err != nil {
+		return nil, fmt.Errorf("failed to list pod stats: %v", err)
 	}
-	return summary, nil
+
+	nodeStats := statsapi.NodeStats{
+		NodeName:         node.Name,
+		CPU:              rootStats.CPU,
+		Memory:           rootStats.Memory,
+		StartTime:        rootStats.StartTime,
+		SystemContainers: sp.GetSystemContainersCPUAndMemoryStats(nodeConfig, podStats, false),
+	}
+	summary := statsapi.Summary{
+		Node: nodeStats,
+		Pods: podStats,
+	}
+	return &summary, nil
 }