Add crictl statsp command

This new command can be used to retrieve the pod sandbox statistics in
the same way the `crictl stats` command exist.

Fixes #841

Signed-off-by: Sascha Grunert <sgrunert@redhat.com>

cmd/crictl/display.go

@@ -31,6 +31,7 @@ const (
 	columnState      = "STATE"
 	columnName       = "NAME"
 	columnAttempt    = "ATTEMPT"
+	columnPodName    = "POD"
 	columnPodID      = "POD ID"
 	columnPodRuntime = "RUNTIME"
 	columnNamespace  = "NAMESPACE"

cmd/crictl/main.go

@@ -176,6 +176,7 @@ func main() {
 		updateContainerCommand,
 		configCommand,
 		statsCommand,
+		podStatsCommand,
 		completionCommand,
 	}
 

cmd/crictl/pod_stats.go

@@ -0,0 +1,266 @@
+/*
+Copyright 2022 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package main
+
+import (
+	"fmt"
+	"sort"
+	"time"
+
+	"github.com/docker/go-units"
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+	"github.com/urfave/cli/v2"
+	"golang.org/x/net/context"
+	cri "k8s.io/cri-api/pkg/apis"
+	pb "k8s.io/cri-api/pkg/apis/runtime/v1"
+)
+
+type podStatsOptions struct {
+	// id of the pod sandbox
+	id string
+
+	// sample is the duration for sampling cpu usage.
+	sample time.Duration
+
+	// labels are selectors for the sandbox
+	labels map[string]string
+
+	// output format
+	output string
+
+	// live watch
+	watch bool
+}
+
+var podStatsCommand = &cli.Command{
+	Name:                   "statsp",
+	Usage:                  "List pod resource usage statistics",
+	UseShortOptionHandling: true,
+	ArgsUsage:              "[ID]",
+	Flags: []cli.Flag{
+		&cli.StringFlag{
+			Name:  "id",
+			Value: "",
+			Usage: "Filter by pod id",
+		},
+		&cli.StringSliceFlag{
+			Name:  "label",
+			Usage: "Filter by key=value label",
+		},
+		&cli.StringFlag{
+			Name:    "output",
+			Aliases: []string{"o"},
+			Usage:   "Output format, One of: json|yaml|table",
+		},
+		&cli.IntFlag{
+			Name:    "seconds",
+			Aliases: []string{"s"},
+			Value:   1,
+			Usage:   "Sample duration for CPU usage in seconds",
+		},
+		&cli.BoolFlag{
+			Name:    "watch",
+			Aliases: []string{"w"},
+			Usage:   "Watch pod resources",
+		},
+	},
+	Action: func(ctx *cli.Context) error {
+		client, err := getRuntimeService(ctx)
+		if err != nil {
+			return errors.Wrap(err, "get runtime service")
+		}
+
+		id := ctx.String("id")
+		if id == "" && ctx.NArg() > 0 {
+			id = ctx.Args().Get(0)
+		}
+
+		opts := podStatsOptions{
+			id:     id,
+			sample: time.Duration(ctx.Int("seconds")) * time.Second,
+			output: ctx.String("output"),
+			watch:  ctx.Bool("watch"),
+		}
+		opts.labels, err = parseLabelStringSlice(ctx.StringSlice("label"))
+		if err != nil {
+			return errors.Wrap(err, "parse pod labels")
+		}
+
+		return errors.Wrap(podStats(ctx.Context, client, opts), "get pod stats")
+	},
+}
+
+type podStatsByID []*pb.PodSandboxStats
+
+func (c podStatsByID) Len() int      { return len(c) }
+func (c podStatsByID) Swap(i, j int) { c[i], c[j] = c[j], c[i] }
+func (c podStatsByID) Less(i, j int) bool {
+	return c[i].Attributes.Id < c[j].Attributes.Id
+}
+
+func podStats(
+	ctx context.Context,
+	client cri.RuntimeService,
+	opts podStatsOptions,
+) error {
+	filter := &pb.PodSandboxStatsFilter{}
+	if opts.id != "" {
+		filter.Id = opts.id
+	}
+	if opts.labels != nil {
+		filter.LabelSelector = opts.labels
+	}
+
+	display := newTableDisplay(20, 1, 3, ' ', 0)
+	if opts.watch {
+		displayErrCh := make(chan error, 1)
+		ticker := time.NewTicker(500 * time.Millisecond)
+		defer ticker.Stop()
+
+		watchCtx, cancelFn := context.WithCancel(context.Background())
+		defer cancelFn()
+
+		// Put the displayPodStats in another goroutine, because it might be
+		// time consuming with lots of pods and we want to cancel it
+		// ASAP when user hit CtrlC
+		go func() {
+			for range ticker.C {
+				if err := displayPodStats(watchCtx, client, filter, display, opts); err != nil {
+					displayErrCh <- err
+					break
+				}
+			}
+		}()
+
+		// listen for CtrlC or error
+		select {
+		case <-SetupInterruptSignalHandler():
+			cancelFn()
+			return nil
+		case err := <-displayErrCh:
+			return err
+		}
+	}
+
+	if err := displayPodStats(ctx, client, filter, display, opts); err != nil {
+		return errors.Wrap(err, "display pod stats")
+	}
+
+	return nil
+}
+
+func displayPodStats(
+	ctx context.Context,
+	client cri.RuntimeService,
+	filter *pb.PodSandboxStatsFilter,
+	display *display,
+	opts podStatsOptions,
+) error {
+	stats, err := getPodSandboxStats(client, filter)
+	if err != nil {
+		return err
+	}
+
+	response := &pb.ListPodSandboxStatsResponse{Stats: stats}
+	switch opts.output {
+	case "json":
+		return outputProtobufObjAsJSON(response)
+	case "yaml":
+		return outputProtobufObjAsYAML(response)
+	}
+
+	oldStats := make(map[string]*pb.PodSandboxStats)
+	for _, s := range stats {
+		if ctx.Err() != nil {
+			return ctx.Err()
+		}
+		oldStats[s.Attributes.Id] = s
+	}
+
+	time.Sleep(opts.sample)
+
+	stats, err = getPodSandboxStats(client, filter)
+	if err != nil {
+		return err
+	}
+
+	display.AddRow([]string{columnPodName, columnPodID, columnCPU, columnMemory})
+	for _, s := range stats {
+		if ctx.Err() != nil {
+			return ctx.Err()
+		}
+		id := getTruncatedID(s.Attributes.Id, "")
+
+		linux := s.GetLinux()
+		var cpu, mem uint64
+		if linux != nil {
+			cpu = linux.GetCpu().GetUsageCoreNanoSeconds().GetValue()
+			mem = linux.GetMemory().GetWorkingSetBytes().GetValue()
+		}
+
+		if cpu == 0 && mem == 0 {
+			// Skip without data, maybe windows pod
+			continue
+		}
+
+		old, ok := oldStats[s.Attributes.Id]
+		if !ok {
+			// Skip new pod
+			continue
+		}
+		oldLinux := old.GetLinux()
+
+		var cpuPerc float64
+		if cpu != 0 {
+			// Only generate cpuPerc for running sandbox
+			duration := linux.GetCpu().GetTimestamp() - oldLinux.GetCpu().GetTimestamp()
+			if duration == 0 {
+				return errors.Errorf("cpu stat is not updated during sample")
+			}
+			cpuPerc = float64(cpu-oldLinux.GetCpu().GetUsageCoreNanoSeconds().GetValue()) / float64(duration) * 100
+		}
+		display.AddRow([]string{
+			s.Attributes.GetMetadata().GetName(),
+			id,
+			fmt.Sprintf("%.2f", cpuPerc),
+			units.HumanSize(float64(mem)),
+		})
+
+	}
+	display.ClearScreen()
+	display.Flush()
+
+	return nil
+}
+
+func getPodSandboxStats(
+	client cri.RuntimeService,
+	filter *pb.PodSandboxStatsFilter,
+) ([]*pb.PodSandboxStats, error) {
+	logrus.Debugf("PodSandboxStatsFilter: %v", filter)
+
+	stats, err := client.ListPodSandboxStats(filter)
+	if err != nil {
+		return nil, errors.Wrap(err, "list pod sandbox stats")
+	}
+	logrus.Debugf("Stats: %v", stats)
+
+	sort.Sort(podStatsByID(stats))
+
+	return stats, nil
+}