feat: introducing a karmada top command

Signed-off-by: chaunceyjiang <chaunceyjiang@gmail.com>

pkg/karmadactl/karmadactl.go

@@ -28,6 +28,7 @@ import (
 	"github.com/karmada-io/karmada/pkg/karmadactl/register"
 	"github.com/karmada-io/karmada/pkg/karmadactl/taint"
 	"github.com/karmada-io/karmada/pkg/karmadactl/token"
+	"github.com/karmada-io/karmada/pkg/karmadactl/top"
 	"github.com/karmada-io/karmada/pkg/karmadactl/unjoin"
 	"github.com/karmada-io/karmada/pkg/karmadactl/util"
 	"github.com/karmada-io/karmada/pkg/version/sharedcommand"
@@ -106,6 +107,7 @@ func NewKarmadaCtlCommand(cmdUse, parentCommand string) *cobra.Command {
 			Commands: []*cobra.Command{
 				apply.NewCmdApply(f, parentCommand, ioStreams),
 				promote.NewCmdPromote(f, parentCommand),
+				top.NewCmdTop(f, parentCommand, ioStreams),
 			},
 		},
 	}

pkg/karmadactl/top/metrics_printer.go

@@ -0,0 +1,209 @@
+package top
+
+import (
+	"fmt"
+	"io"
+	"sort"
+
+	corev1 "k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/api/resource"
+	"k8s.io/cli-runtime/pkg/printers"
+	"k8s.io/kubectl/pkg/metricsutil"
+	metricsapi "k8s.io/metrics/pkg/apis/metrics"
+)
+
+var (
+	MeasuredResources = []corev1.ResourceName{
+		corev1.ResourceCPU,
+		corev1.ResourceMemory,
+	}
+	PodColumns        = []string{"NAME", "CPU(cores)", "MEMORY(bytes)"}
+	ClusterNameColumn = "CLUSTER"
+	NamespaceColumn   = "NAMESPACE"
+	PodColumn         = "POD"
+)
+
+type ResourceMetricsInfo struct {
+	Cluster   string
+	Name      string
+	Metrics   corev1.ResourceList
+	Available corev1.ResourceList
+}
+
+type TopCmdPrinter struct {
+	out io.Writer
+}
+
+func NewTopCmdPrinter(out io.Writer) *TopCmdPrinter {
+	return &TopCmdPrinter{out: out}
+}
+
+func (printer *TopCmdPrinter) PrintPodMetrics(metrics []metricsapi.PodMetrics, printContainers, withNamespace, noHeaders bool, sortBy string, sum bool) error {
+	if len(metrics) == 0 {
+		return nil
+	}
+	w := printers.GetNewTabWriter(printer.out)
+	defer w.Flush()
+
+	columnWidth := len(PodColumns)
+	columnWidth++
+	if !noHeaders {
+		printValue(w, ClusterNameColumn)
+		if withNamespace {
+			printValue(w, NamespaceColumn)
+			columnWidth++
+		}
+		if printContainers {
+			printValue(w, PodColumn)
+			columnWidth++
+		}
+		printColumnNames(w, PodColumns)
+	}
+
+	sort.Sort(metricsutil.NewPodMetricsSorter(metrics, withNamespace, sortBy))
+
+	for _, m := range metrics {
+		if printContainers {
+			sort.Sort(metricsutil.NewContainerMetricsSorter(m.Containers, sortBy))
+			printSinglePodContainerMetrics(w, &m, withNamespace)
+		} else {
+			printSinglePodMetrics(w, &m, withNamespace)
+		}
+
+	}
+
+	if sum {
+		adder := NewResourceAdder(MeasuredResources)
+		for _, m := range metrics {
+			adder.AddPodMetrics(&m)
+		}
+		printPodResourcesSum(w, adder.total, columnWidth)
+	}
+
+	return nil
+}
+
+func printColumnNames(out io.Writer, names []string) {
+	for _, name := range names {
+		printValue(out, name)
+	}
+	fmt.Fprint(out, "\n")
+}
+
+func printSinglePodMetrics(out io.Writer, m *metricsapi.PodMetrics, withNamespace bool) {
+	podMetrics := getPodMetrics(m)
+	printValue(out, m.Annotations["resource.karmada.io/query-from-cluster"])
+	if withNamespace {
+		printValue(out, m.Namespace)
+	}
+	printMetricsLine(out, &ResourceMetricsInfo{
+		Name:      m.Name,
+		Metrics:   podMetrics,
+		Available: corev1.ResourceList{},
+	})
+}
+
+func printSinglePodContainerMetrics(out io.Writer, m *metricsapi.PodMetrics, withNamespace bool) {
+	for _, c := range m.Containers {
+		printValue(out, m.Annotations["resource.karmada.io/query-from-cluster"])
+		if withNamespace {
+			printValue(out, m.Namespace)
+		}
+		printValue(out, m.Name)
+		printMetricsLine(out, &ResourceMetricsInfo{
+			Name:      c.Name,
+			Metrics:   c.Usage,
+			Available: corev1.ResourceList{},
+		})
+	}
+}
+
+func getPodMetrics(m *metricsapi.PodMetrics) corev1.ResourceList {
+	podMetrics := make(corev1.ResourceList)
+	for _, res := range MeasuredResources {
+		podMetrics[res], _ = resource.ParseQuantity("0")
+	}
+
+	for _, c := range m.Containers {
+		for _, res := range MeasuredResources {
+			quantity := podMetrics[res]
+			quantity.Add(c.Usage[res])
+			podMetrics[res] = quantity
+		}
+	}
+	return podMetrics
+}
+
+func printMetricsLine(out io.Writer, metrics *ResourceMetricsInfo) {
+	printValue(out, metrics.Name)
+	printAllResourceUsages(out, metrics)
+	fmt.Fprint(out, "\n")
+}
+
+func printValue(out io.Writer, value interface{}) {
+	fmt.Fprintf(out, "%v\t", value)
+}
+
+func printAllResourceUsages(out io.Writer, metrics *ResourceMetricsInfo) {
+	for _, res := range MeasuredResources {
+		quantity := metrics.Metrics[res]
+		printSingleResourceUsage(out, res, quantity)
+		fmt.Fprint(out, "\t")
+		if available, found := metrics.Available[res]; found {
+			fraction := float64(quantity.MilliValue()) / float64(available.MilliValue()) * 100
+			fmt.Fprintf(out, "%d%%\t", int64(fraction))
+		}
+	}
+}
+
+func printSingleResourceUsage(out io.Writer, resourceType corev1.ResourceName, quantity resource.Quantity) {
+	switch resourceType {
+	case corev1.ResourceCPU:
+		fmt.Fprintf(out, "%vm", quantity.MilliValue())
+	case corev1.ResourceMemory:
+		fmt.Fprintf(out, "%vMi", quantity.Value()/(1024*1024))
+	default:
+		fmt.Fprintf(out, "%v", quantity.Value())
+	}
+}
+
+func printPodResourcesSum(out io.Writer, total corev1.ResourceList, columnWidth int) {
+	for i := 0; i < columnWidth-2; i++ {
+		printValue(out, "")
+	}
+	printValue(out, "________")
+	printValue(out, "________")
+	fmt.Fprintf(out, "\n")
+	for i := 0; i < columnWidth-3; i++ {
+		printValue(out, "")
+	}
+	printMetricsLine(out, &ResourceMetricsInfo{
+		Name:      "",
+		Metrics:   total,
+		Available: corev1.ResourceList{},
+	})
+
+}
+
+type ResourceAdder struct {
+	resources []corev1.ResourceName
+	total     corev1.ResourceList
+}
+
+func NewResourceAdder(resources []corev1.ResourceName) *ResourceAdder {
+	return &ResourceAdder{
+		resources: resources,
+		total:     make(corev1.ResourceList),
+	}
+}
+
+// AddPodMetrics adds each pod metric to the total
+func (adder *ResourceAdder) AddPodMetrics(m *metricsapi.PodMetrics) {
+	for _, c := range m.Containers {
+		for _, res := range adder.resources {
+			total := adder.total[res]
+			total.Add(c.Usage[res])
+			adder.total[res] = total
+		}
+	}
+}

pkg/karmadactl/top/top.go

@@ -0,0 +1,58 @@
+package top
+
+import (
+	"github.com/spf13/cobra"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/cli-runtime/pkg/genericclioptions"
+	cmdutil "k8s.io/kubectl/pkg/cmd/util"
+	"k8s.io/kubectl/pkg/util/i18n"
+	"k8s.io/kubectl/pkg/util/templates"
+	metricsapi "k8s.io/metrics/pkg/apis/metrics"
+)
+
+const (
+	sortByCPU    = "cpu"
+	sortByMemory = "memory"
+)
+
+var (
+	supportedMetricsAPIVersions = []string{
+		"v1beta1",
+	}
+	topLong = templates.LongDesc(i18n.T(`
+		Display Resource (CPU/Memory) usage of member clusters.
+
+		The top command allows you to see the resource consumption for nodes or pods of member clusters.
+
+		This command requires Metrics Server to be correctly configured and working on the server. `))
+)
+
+func NewCmdTop(f cmdutil.Factory, parentCommand string, streams genericclioptions.IOStreams) *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "top",
+		Short: i18n.T("Display resource (CPU/memory) usage of member clusters"),
+		Long:  topLong,
+		Run:   cmdutil.DefaultSubCommandRun(streams.ErrOut),
+	}
+
+	// create subcommands
+	cmd.AddCommand(NewCmdTopPod(f, nil, streams))
+
+	return cmd
+}
+
+func SupportedMetricsAPIVersionAvailable(discoveredAPIGroups *metav1.APIGroupList) bool {
+	for _, discoveredAPIGroup := range discoveredAPIGroups.Groups {
+		if discoveredAPIGroup.Name != metricsapi.GroupName {
+			continue
+		}
+		for _, version := range discoveredAPIGroup.Versions {
+			for _, supportedVersion := range supportedMetricsAPIVersions {
+				if version.Version == supportedVersion {
+					return true
+				}
+			}
+		}
+	}
+	return false
+}