2 files changed, 245 insertions, 1 deletions
diff --git a/cmd/podman/containers/ps.go b/cmd/podman/containers/ps.go
index c5696a158..fd0b68195 100644
--- a/cmd/podman/containers/ps.go
+++ b/cmd/podman/containers/ps.go
@@ -206,7 +206,7 @@ func ps(cmd *cobra.Command, args []string) error {
 				return err
 			}
 			if err := tmpl.Execute(w, responses); err != nil {
-				return nil
+				return err
 			}
 			if err := w.Flush(); err != nil {
 				return err
diff --git a/cmd/podman/containers/stats.go b/cmd/podman/containers/stats.go
new file mode 100644
index 000000000..3f9db671f
--- /dev/null
+++ b/cmd/podman/containers/stats.go
@@ -0,0 +1,244 @@
+package containers
+
+import (
+	"fmt"
+	"os"
+	"strings"
+	"text/tabwriter"
+	"text/template"
+
+	tm "github.com/buger/goterm"
+	"github.com/containers/libpod/cmd/podman/registry"
+	"github.com/containers/libpod/libpod/define"
+	"github.com/containers/libpod/pkg/cgroups"
+	"github.com/containers/libpod/pkg/domain/entities"
+	"github.com/containers/libpod/pkg/rootless"
+	"github.com/containers/libpod/utils"
+	"github.com/docker/go-units"
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+	"github.com/spf13/cobra"
+	"github.com/spf13/pflag"
+)
+
+var (
+	statsDescription = "Display percentage of CPU, memory, network I/O, block I/O and PIDs for one or more containers."
+	statsCommand     = &cobra.Command{
+		Use:   "stats [flags] [CONTAINER...]",
+		Short: "Display a live stream of container resource usage statistics",
+		Long:  statsDescription,
+		RunE:  stats,
+		Args:  checkStatOptions,
+		Example: `podman stats --all --no-stream
+  podman stats ctrID
+  podman stats --no-stream --format "table {{.ID}} {{.Name}} {{.MemUsage}}" ctrID`,
+	}
+
+	containerStatsCommand = &cobra.Command{
+		Use:   statsCommand.Use,
+		Short: statsCommand.Short,
+		Long:  statsCommand.Long,
+		RunE:  statsCommand.RunE,
+		Args:  checkStatOptions,
+		Example: `podman container stats --all --no-stream
+  podman container stats ctrID
+  podman container stats --no-stream --format "table {{.ID}} {{.Name}} {{.MemUsage}}" ctrID`,
+	}
+)
+
+var (
+	statsOptions       entities.ContainerStatsOptions
+	defaultStatsRow    = "{{.ID}}\t{{.Name}}\t{{.CPUPerc}}\t{{.MemUsage}}\t{{.MemPerc}}\t{{.NetIO}}\t{{.BlockIO}}\t{{.PIDS}}\n"
+	defaultStatsHeader = "ID\tNAME\tCPU %\tMEM USAGE / LIMIT\tMEM %\tNET IO\tBLOCK IO\tPIDS\n"
+)
+
+func statFlags(flags *pflag.FlagSet) {
+	flags.BoolVarP(&statsOptions.All, "all", "a", false, "Show all containers. Only running containers are shown by default. The default is false")
+	flags.StringVar(&statsOptions.Format, "format", "", "Pretty-print container statistics to JSON or using a Go template")
+	flags.BoolVarP(&statsOptions.Latest, "latest", "l", false, "Act on the latest container Podman is aware of")
+	flags.BoolVar(&statsOptions.NoReset, "no-reset", false, "Disable resetting the screen between intervals")
+	flags.BoolVar(&statsOptions.NoStream, "no-stream", false, "Disable streaming stats and only pull the first result, default setting is false")
+	if registry.IsRemote() {
+		_ = flags.MarkHidden("latest")
+	}
+}
+
+func init() {
+	registry.Commands = append(registry.Commands, registry.CliCommand{
+		Mode:    []entities.EngineMode{entities.ABIMode, entities.TunnelMode},
+		Command: statsCommand,
+	})
+	flags := statsCommand.Flags()
+	statFlags(flags)
+
+	registry.Commands = append(registry.Commands, registry.CliCommand{
+		Mode:    []entities.EngineMode{entities.ABIMode, entities.TunnelMode},
+		Command: containerStatsCommand,
+		Parent:  containerCmd,
+	})
+
+	containerStatsFlags := containerStatsCommand.Flags()
+	statFlags(containerStatsFlags)
+}
+
+// stats is different in that it will assume running containers if
+// no input is given, so we need to validate differently
+func checkStatOptions(cmd *cobra.Command, args []string) error {
+	opts := 0
+	if statsOptions.All {
+		opts += 1
+	}
+	if statsOptions.Latest {
+		opts += 1
+	}
+	if len(args) > 0 {
+		opts += 1
+	}
+	if opts > 1 {
+		return errors.Errorf("--all, --latest and containers cannot be used together")
+	}
+	return nil
+}
+
+func stats(cmd *cobra.Command, args []string) error {
+	if rootless.IsRootless() {
+		unified, err := cgroups.IsCgroup2UnifiedMode()
+		if err != nil {
+			return err
+		}
+		if !unified {
+			return errors.New("stats is not supported in rootless mode without cgroups v2")
+		}
+	}
+	statsOptions.StatChan = make(chan []*define.ContainerStats, 1)
+	go func() {
+		for reports := range statsOptions.StatChan {
+			if err := outputStats(reports); err != nil {
+				logrus.Error(err)
+			}
+		}
+	}()
+	return registry.ContainerEngine().ContainerStats(registry.Context(), args, statsOptions)
+}
+
+func outputStats(reports []*define.ContainerStats) error {
+	if len(statsOptions.Format) < 1 && !statsOptions.NoReset {
+		tm.Clear()
+		tm.MoveCursor(1, 1)
+		tm.Flush()
+	}
+	var stats []*containerStats
+	for _, r := range reports {
+		stats = append(stats, &containerStats{r})
+	}
+	if statsOptions.Format == "json" {
+		return outputJSON(stats)
+	}
+	format := defaultStatsRow
+	if len(statsOptions.Format) > 0 {
+		format = statsOptions.Format
+		if !strings.HasSuffix(format, "\n") {
+			format += "\n"
+		}
+	}
+	format = "{{range . }}" + format + "{{end}}"
+	if len(statsOptions.Format) < 1 {
+		format = defaultStatsHeader + format
+	}
+	tmpl, err := template.New("stats").Parse(format)
+	if err != nil {
+		return err
+	}
+	w := tabwriter.NewWriter(os.Stdout, 8, 2, 2, ' ', 0)
+	if err := tmpl.Execute(w, stats); err != nil {
+		return err
+	}
+	if err := w.Flush(); err != nil {
+		return err
+	}
+	return nil
+}
+
+type containerStats struct {
+	*define.ContainerStats
+}
+
+func (s *containerStats) ID() string {
+	return s.ContainerID[0:12]
+}
+
+func (s *containerStats) CPUPerc() string {
+	return floatToPercentString(s.CPU)
+}
+
+func (s *containerStats) MemPerc() string {
+	return floatToPercentString(s.ContainerStats.MemPerc)
+}
+
+func (s *containerStats) NetIO() string {
+	return combineHumanValues(s.NetInput, s.NetOutput)
+}
+
+func (s *containerStats) BlockIO() string {
+	return combineHumanValues(s.BlockInput, s.BlockOutput)
+}
+
+func (s *containerStats) PIDS() string {
+	if s.PIDs == 0 {
+		// If things go bazinga, return a safe value
+		return "--"
+	}
+	return fmt.Sprintf("%d", s.PIDs)
+}
+func (s *containerStats) MemUsage() string {
+	return combineHumanValues(s.ContainerStats.MemUsage, s.ContainerStats.MemLimit)
+}
+
+func floatToPercentString(f float64) string {
+	strippedFloat, err := utils.RemoveScientificNotationFromFloat(f)
+	if err != nil || strippedFloat == 0 {
+		// If things go bazinga, return a safe value
+		return "--"
+	}
+	return fmt.Sprintf("%.2f", strippedFloat) + "%"
+}
+
+func combineHumanValues(a, b uint64) string {
+	if a == 0 && b == 0 {
+		return "-- / --"
+	}
+	return fmt.Sprintf("%s / %s", units.HumanSize(float64(a)), units.HumanSize(float64(b)))
+}
+
+func outputJSON(stats []*containerStats) error {
+	type jstat struct {
+		Id         string `json:"id"`
+		Name       string `json:"name"`
+		CpuPercent string `json:"cpu_percent"`
+		MemUsage   string `json:"mem_usage"`
+		MemPerc    string `json:"mem_percent"`
+		NetIO      string `json:"net_io"`
+		BlockIO    string `json:"block_io"`
+		Pids       string `json:"pids"`
+	}
+	var jstats []jstat
+	for _, j := range stats {
+		jstats = append(jstats, jstat{
+			Id:         j.ID(),
+			Name:       j.Name,
+			CpuPercent: j.CPUPerc(),
+			MemUsage:   j.MemPerc(),
+			MemPerc:    j.MemUsage(),
+			NetIO:      j.NetIO(),
+			BlockIO:    j.BlockIO(),
+			Pids:       j.PIDS(),
+		})
+	}
+
+	b, err := json.MarshalIndent(jstats, "", " ")
+	if err != nil {
+		return err
+	}
+	fmt.Println(string(b))
+	return nil
+}