implement pod stats

Implement pod stats for the local and remote client. Both code paths end
up in infra/abi to allow for code share.

Signed-off-by: Valentin Rothberg <rothberg@redhat.com>

1 files changed, 189 insertions, 0 deletions

diff --git a/cmd/podman/pods/stats.go b/cmd/podman/pods/stats.go
new file mode 100644
index 000000000..7c3597d9a
--- /dev/null
+++ b/cmd/podman/pods/stats.go
@@ -0,0 +1,189 @@
+package pods
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"reflect"
+	"strings"
+	"text/tabwriter"
+	"text/template"
+	"time"
+
+	"github.com/buger/goterm"
+	"github.com/containers/buildah/pkg/formats"
+	"github.com/containers/libpod/cmd/podman/registry"
+	"github.com/containers/libpod/pkg/domain/entities"
+	"github.com/containers/libpod/pkg/util/camelcase"
+	"github.com/spf13/cobra"
+)
+
+type podStatsOptionsWrapper struct {
+	entities.PodStatsOptions
+
+	// Format - pretty-print to JSON or a go template.
+	Format string
+	// NoReset - do not reset the screen when streaming.
+	NoReset bool
+	// NoStream - do not stream stats but write them once.
+	NoStream bool
+}
+
+var (
+	statsOptions     = podStatsOptionsWrapper{}
+	statsDescription = `Display the containers' resource-usage statistics of one or more running pod`
+	// Command: podman pod _pod_
+	statsCmd = &cobra.Command{
+		Use:   "stats [flags] [POD...]",
+		Short: "Display resource-usage statistics of pods",
+		Long:  statsDescription,
+		RunE:  stats,
+		Example: `podman pod stats
+  podman pod stats a69b23034235 named-pod
+  podman pod stats --latest
+  podman pod stats --all`,
+	}
+)
+
+func init() {
+	registry.Commands = append(registry.Commands, registry.CliCommand{
+		Mode:    []entities.EngineMode{entities.ABIMode, entities.TunnelMode},
+		Command: statsCmd,
+		Parent:  podCmd,
+	})
+
+	flags := statsCmd.Flags()
+	flags.BoolVarP(&statsOptions.All, "all", "a", false, "Provide stats for all pods")
+	flags.StringVar(&statsOptions.Format, "format", "", "Pretty-print container statistics to JSON or using a Go template")
+	flags.BoolVarP(&statsOptions.Latest, "latest", "l", false, "Provide stats on the latest pod Podman is aware of")
+	flags.BoolVar(&statsOptions.NoReset, "no-reset", false, "Disable resetting the screen when streaming")
+	flags.BoolVar(&statsOptions.NoStream, "no-stream", false, "Disable streaming stats and only pull the first result")
+
+	if registry.IsRemote() {
+		_ = flags.MarkHidden("latest")
+	}
+}
+
+func stats(cmd *cobra.Command, args []string) error {
+	// Validate input.
+	if err := entities.ValidatePodStatsOptions(args, &statsOptions.PodStatsOptions); err != nil {
+		return err
+	}
+
+	format := statsOptions.Format
+	doJson := strings.ToLower(format) == formats.JSONString
+	header := getPodStatsHeader(format)
+
+	for {
+		reports, err := registry.ContainerEngine().PodStats(context.Background(), args, statsOptions.PodStatsOptions)
+		if err != nil {
+			return err
+		}
+		// Print the stats in the requested format and configuration.
+		if doJson {
+			if err := printJSONPodStats(reports); err != nil {
+				return err
+			}
+		} else {
+			if !statsOptions.NoReset {
+				goterm.Clear()
+				goterm.MoveCursor(1, 1)
+				goterm.Flush()
+			}
+			if len(format) == 0 {
+				printPodStatsLines(reports)
+			} else if err := printFormattedPodStatsLines(format, reports, header); err != nil {
+				return err
+			}
+		}
+		if statsOptions.NoStream {
+			break
+		}
+		time.Sleep(time.Second)
+	}
+
+	return nil
+}
+
+func printJSONPodStats(stats []*entities.PodStatsReport) error {
+	b, err := json.MarshalIndent(&stats, "", "     ")
+	if err != nil {
+		return err
+	}
+	fmt.Fprintf(os.Stdout, "%s\n", string(b))
+	return nil
+}
+
+func printPodStatsLines(stats []*entities.PodStatsReport) {
+	w := tabwriter.NewWriter(os.Stdout, 0, 0, 2, ' ', 0)
+	outFormat := "%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\n"
+	fmt.Fprintf(w, outFormat, "POD", "CID", "NAME", "CPU %", "MEM USAGE/ LIMIT", "MEM %", "NET IO", "BLOCK IO", "PIDS")
+	for _, i := range stats {
+		if len(stats) == 0 {
+			fmt.Fprintf(w, outFormat, i.Pod, "--", "--", "--", "--", "--", "--", "--", "--")
+		} else {
+			fmt.Fprintf(w, outFormat, i.Pod, i.CID, i.Name, i.CPU, i.MemUsage, i.Mem, i.NetIO, i.BlockIO, i.PIDS)
+		}
+	}
+	w.Flush()
+}
+
+func printFormattedPodStatsLines(format string, stats []*entities.PodStatsReport, headerNames map[string]string) error {
+	if len(stats) == 0 {
+		return nil
+	}
+
+	// Use a tabwriter to align column format
+	w := tabwriter.NewWriter(os.Stdout, 0, 0, 3, ' ', 0)
+	// Spit out the header if "table" is present in the format
+	if strings.HasPrefix(format, "table") {
+		hformat := strings.Replace(strings.TrimSpace(format[5:]), " ", "\t", -1)
+		format = hformat
+		headerTmpl, err := template.New("header").Parse(hformat)
+		if err != nil {
+			return err
+		}
+		if err := headerTmpl.Execute(w, headerNames); err != nil {
+			return err
+		}
+		fmt.Fprintln(w, "")
+	}
+
+	// Spit out the data rows now
+	dataTmpl, err := template.New("data").Parse(format)
+	if err != nil {
+		return err
+	}
+	for _, s := range stats {
+		if err := dataTmpl.Execute(w, s); err != nil {
+			return err
+		}
+		fmt.Fprintln(w, "")
+	}
+	// Flush the writer
+	return w.Flush()
+
+}
+
+// getPodStatsHeader returns the stats header for the specified options.
+func getPodStatsHeader(format string) map[string]string {
+	headerNames := make(map[string]string)
+	if format == "" {
+		return headerNames
+	}
+	// Make a map of the field names for the headers
+	v := reflect.ValueOf(entities.PodStatsReport{})
+	t := v.Type()
+	for i := 0; i < t.NumField(); i++ {
+		split := camelcase.Split(t.Field(i).Name)
+		value := strings.ToUpper(strings.Join(split, " "))
+		switch value {
+		case "CPU", "MEM":
+			value += " %"
+		case "MEM USAGE":
+			value = "MEM USAGE / LIMIT"
+		}
+		headerNames[t.Field(i).Name] = value
+	}
+	return headerNames
+}