Add the format switch to the stats command

Signed-off-by: Boaz Shuster <ripcurld.github@gmail.com>

command/container/stats.go

@@ -5,17 +5,16 @@ import (
 	"io"
 	"strings"
 	"sync"
-	"text/tabwriter"
 	"time"
 
 	"golang.org/x/net/context"
 
-	"github.com/Sirupsen/logrus"
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/api/types/events"
 	"github.com/docker/docker/api/types/filters"
 	"github.com/docker/docker/cli"
 	"github.com/docker/docker/cli/command"
+	"github.com/docker/docker/cli/command/formatter"
 	"github.com/docker/docker/cli/command/system"
 	"github.com/spf13/cobra"
 )
@@ -23,7 +22,7 @@ import (
 type statsOptions struct {
 	all        bool
 	noStream   bool
-
+	format     string
 	containers []string
 }
 
@@ -44,6 +43,7 @@ func NewStatsCommand(dockerCli *command.DockerCli) *cobra.Command {
 	flags := cmd.Flags()
 	flags.BoolVarP(&opts.all, "all", "a", false, "Show all containers (default shows just running)")
 	flags.BoolVar(&opts.noStream, "no-stream", false, "Disable streaming stats and only pull the first result")
+	flags.StringVar(&opts.format, "format", "", "Pretty-print images using a Go template")
 	return cmd
 }
 
@@ -98,10 +98,10 @@ func runStats(dockerCli *command.DockerCli, opts *statsOptions) error {
 			closeChan <- err
 		}
 		for _, container := range cs {
-			s := &containerStats{Name: container.ID[:12]}
+			s := formatter.NewContainerStats(container.ID[:12], daemonOSType)
 			if cStats.add(s) {
 				waitFirst.Add(1)
-				go s.Collect(ctx, dockerCli.Client(), !opts.noStream, waitFirst)
+				go collect(s, ctx, dockerCli.Client(), !opts.noStream, waitFirst)
 			}
 		}
 	}
@@ -115,19 +115,19 @@ func runStats(dockerCli *command.DockerCli, opts *statsOptions) error {
 		eh := system.InitEventHandler()
 		eh.Handle("create", func(e events.Message) {
 			if opts.all {
-				s := &containerStats{Name: e.ID[:12]}
+				s := formatter.NewContainerStats(e.ID[:12], daemonOSType)
 				if cStats.add(s) {
 					waitFirst.Add(1)
-					go s.Collect(ctx, dockerCli.Client(), !opts.noStream, waitFirst)
+					go collect(s, ctx, dockerCli.Client(), !opts.noStream, waitFirst)
 				}
 			}
 		})
 
 		eh.Handle("start", func(e events.Message) {
-			s := &containerStats{Name: e.ID[:12]}
+			s := formatter.NewContainerStats(e.ID[:12], daemonOSType)
 			if cStats.add(s) {
 				waitFirst.Add(1)
-				go s.Collect(ctx, dockerCli.Client(), !opts.noStream, waitFirst)
+				go collect(s, ctx, dockerCli.Client(), !opts.noStream, waitFirst)
 			}
 		})
 
@@ -150,10 +150,10 @@ func runStats(dockerCli *command.DockerCli, opts *statsOptions) error {
 		// Artificially send creation events for the containers we were asked to
 		// monitor (same code path than we use when monitoring all containers).
 		for _, name := range opts.containers {
-			s := &containerStats{Name: name}
+			s := formatter.NewContainerStats(name, daemonOSType)
 			if cStats.add(s) {
 				waitFirst.Add(1)
-				go s.Collect(ctx, dockerCli.Client(), !opts.noStream, waitFirst)
+				go collect(s, ctx, dockerCli.Client(), !opts.noStream, waitFirst)
 			}
 		}
 
@@ -166,11 +166,11 @@ func runStats(dockerCli *command.DockerCli, opts *statsOptions) error {
 		var errs []string
 		cStats.mu.Lock()
 		for _, c := range cStats.cs {
-			c.mu.Lock()
+			c.Mu.Lock()
-			if c.err != nil {
+			if c.Err != nil {
-				errs = append(errs, fmt.Sprintf("%s: %v", c.Name, c.err))
+				errs = append(errs, fmt.Sprintf("%s: %v", c.Name, c.Err))
 			}
-			c.mu.Unlock()
+			c.Mu.Unlock()
 		}
 		cStats.mu.Unlock()
 		if len(errs) > 0 {
@@ -180,44 +180,34 @@ func runStats(dockerCli *command.DockerCli, opts *statsOptions) error {
 
 	// before print to screen, make sure each container get at least one valid stat data
 	waitFirst.Wait()
+	f := "table"
+	if len(opts.format) > 0 {
+		f = opts.format
+	}
+	statsCtx := formatter.Context{
+		Output: dockerCli.Out(),
+		Format: formatter.NewStatsFormat(f, daemonOSType),
+	}
 
-	w := tabwriter.NewWriter(dockerCli.Out(), 20, 1, 3, ' ', 0)
+	cleanHeader := func() {
-	printHeader := func() {
 		if !opts.noStream {
 			fmt.Fprint(dockerCli.Out(), "\033[2J")
 			fmt.Fprint(dockerCli.Out(), "\033[H")
 		}
-		switch daemonOSType {
-		case "":
-			// Before we have any stats from the daemon, we don't know the platform...
-			io.WriteString(w, "Waiting for statistics...\n")
-		case "windows":
-			io.WriteString(w, "CONTAINER\tCPU %\tPRIV WORKING SET\tNET I/O\tBLOCK I/O\n")
-		default:
-			io.WriteString(w, "CONTAINER\tCPU %\tMEM USAGE / LIMIT\tMEM %\tNET I/O\tBLOCK I/O\tPIDS\n")
-		}
 	}
 
+	var err error
 	for range time.Tick(500 * time.Millisecond) {
-		printHeader()
+		cleanHeader()
-		toRemove := []string{}
+		cStats.mu.RLock()
-		cStats.mu.Lock()
+		csLen := len(cStats.cs)
-		for _, s := range cStats.cs {
+		if err = formatter.ContainerStatsWrite(statsCtx, cStats.cs); err != nil {
-			if err := s.Display(w); err != nil && !opts.noStream {
+			break
-				logrus.Debugf("stats: got error for %s: %v", s.Name, err)
-				if err == io.EOF {
-					toRemove = append(toRemove, s.Name)
 		}
+		cStats.mu.RUnlock()
+		if csLen == 0 && !showAll {
+			break
 		}
-		}
-		cStats.mu.Unlock()
-		for _, name := range toRemove {
-			cStats.remove(name)
-		}
-		if len(cStats.cs) == 0 && !showAll {
-			return nil
-		}
-		w.Flush()
 		if opts.noStream {
 			break
 		}
@@ -237,5 +227,5 @@ func runStats(dockerCli *command.DockerCli, opts *statsOptions) error {
 			// just skip
 		}
 	}
-	return nil
+	return err
 }

command/container/stats_helpers.go

@@ -3,7 +3,6 @@ package container
 import (
 	"encoding/json"
 	"errors"
-	"fmt"
 	"io"
 	"strings"
 	"sync"
@@ -11,30 +10,15 @@ import (
 
 	"github.com/Sirupsen/logrus"
 	"github.com/docker/docker/api/types"
+	"github.com/docker/docker/cli/command/formatter"
 	"github.com/docker/docker/client"
-	"github.com/docker/go-units"
 	"golang.org/x/net/context"
 )
 
-type containerStats struct {
-	Name             string
-	CPUPercentage    float64
-	Memory           float64 // On Windows this is the private working set
-	MemoryLimit      float64 // Not used on Windows
-	MemoryPercentage float64 // Not used on Windows
-	NetworkRx        float64
-	NetworkTx        float64
-	BlockRead        float64
-	BlockWrite       float64
-	PidsCurrent      uint64 // Not used on Windows
-	mu               sync.Mutex
-	err              error
-}
-
 type stats struct {
-	mu     sync.Mutex
 	ostype string
-	cs     []*containerStats
+	mu     sync.RWMutex
+	cs     []*formatter.ContainerStats
 }
 
 // daemonOSType is set once we have at least one stat for a container
@@ -42,7 +26,7 @@ type stats struct {
 // on the daemon platform.
 var daemonOSType string
 
-func (s *stats) add(cs *containerStats) bool {
+func (s *stats) add(cs *formatter.ContainerStats) bool {
 	s.mu.Lock()
 	defer s.mu.Unlock()
 	if _, exists := s.isKnownContainer(cs.Name); !exists {
@@ -69,7 +53,7 @@ func (s *stats) isKnownContainer(cid string) (int, bool) {
 	return -1, false
 }
 
-func (s *containerStats) Collect(ctx context.Context, cli client.APIClient, streamStats bool, waitFirst *sync.WaitGroup) {
+func collect(s *formatter.ContainerStats, ctx context.Context, cli client.APIClient, streamStats bool, waitFirst *sync.WaitGroup) {
 	logrus.Debugf("collecting stats for %s", s.Name)
 	var (
 		getFirst       bool
@@ -88,9 +72,9 @@ func (s *containerStats) Collect(ctx context.Context, cli client.APIClient, stre
 
 	response, err := cli.ContainerStats(ctx, s.Name, streamStats)
 	if err != nil {
-		s.mu.Lock()
+		s.Mu.Lock()
-		s.err = err
+		s.Err = err
-		s.mu.Unlock()
+		s.Mu.Unlock()
 		return
 	}
 	defer response.Body.Close()
@@ -137,7 +121,7 @@ func (s *containerStats) Collect(ctx context.Context, cli client.APIClient, stre
 				mem = float64(v.MemoryStats.PrivateWorkingSet)
 			}
 
-			s.mu.Lock()
+			s.Mu.Lock()
 			s.CPUPercentage = cpuPercent
 			s.Memory = mem
 			s.NetworkRx, s.NetworkTx = calculateNetwork(v.Networks)
@@ -148,7 +132,7 @@ func (s *containerStats) Collect(ctx context.Context, cli client.APIClient, stre
 				s.MemoryPercentage = memPercent
 				s.PidsCurrent = v.PidsStats.Current
 			}
-			s.mu.Unlock()
+			s.Mu.Unlock()
 			u <- nil
 			if !streamStats {
 				return
@@ -160,7 +144,7 @@ func (s *containerStats) Collect(ctx context.Context, cli client.APIClient, stre
 		case <-time.After(2 * time.Second):
 			// zero out the values if we have not received an update within
 			// the specified duration.
-			s.mu.Lock()
+			s.Mu.Lock()
 			s.CPUPercentage = 0
 			s.Memory = 0
 			s.MemoryPercentage = 0
@@ -170,8 +154,8 @@ func (s *containerStats) Collect(ctx context.Context, cli client.APIClient, stre
 			s.BlockRead = 0
 			s.BlockWrite = 0
 			s.PidsCurrent = 0
-			s.err = errors.New("timeout waiting for stats")
+			s.Err = errors.New("timeout waiting for stats")
-			s.mu.Unlock()
+			s.Mu.Unlock()
 			// if this is the first stat you get, release WaitGroup
 			if !getFirst {
 				getFirst = true
@@ -179,12 +163,12 @@ func (s *containerStats) Collect(ctx context.Context, cli client.APIClient, stre
 			}
 		case err := <-u:
 			if err != nil {
-				s.mu.Lock()
+				s.Mu.Lock()
-				s.err = err
+				s.Err = err
-				s.mu.Unlock()
+				s.Mu.Unlock()
 				continue
 			}
-			s.err = nil
+			s.Err = nil
 			// if this is the first stat you get, release WaitGroup
 			if !getFirst {
 				getFirst = true
@@ -197,51 +181,6 @@ func (s *containerStats) Collect(ctx context.Context, cli client.APIClient, stre
 	}
 }
 
-func (s *containerStats) Display(w io.Writer) error {
-	s.mu.Lock()
-	defer s.mu.Unlock()
-	if daemonOSType == "windows" {
-		// NOTE: if you change this format, you must also change the err format below!
-		format := "%s\t%.2f%%\t%s\t%s / %s\t%s / %s\n"
-		if s.err != nil {
-			format = "%s\t%s\t%s\t%s / %s\t%s / %s\n"
-			errStr := "--"
-			fmt.Fprintf(w, format,
-				s.Name, errStr, errStr, errStr, errStr, errStr, errStr,
-			)
-			err := s.err
-			return err
-		}
-		fmt.Fprintf(w, format,
-			s.Name,
-			s.CPUPercentage,
-			units.BytesSize(s.Memory),
-			units.HumanSizeWithPrecision(s.NetworkRx, 3), units.HumanSizeWithPrecision(s.NetworkTx, 3),
-			units.HumanSizeWithPrecision(s.BlockRead, 3), units.HumanSizeWithPrecision(s.BlockWrite, 3))
-	} else {
-		// NOTE: if you change this format, you must also change the err format below!
-		format := "%s\t%.2f%%\t%s / %s\t%.2f%%\t%s / %s\t%s / %s\t%d\n"
-		if s.err != nil {
-			format = "%s\t%s\t%s / %s\t%s\t%s / %s\t%s / %s\t%s\n"
-			errStr := "--"
-			fmt.Fprintf(w, format,
-				s.Name, errStr, errStr, errStr, errStr, errStr, errStr, errStr, errStr, errStr,
-			)
-			err := s.err
-			return err
-		}
-		fmt.Fprintf(w, format,
-			s.Name,
-			s.CPUPercentage,
-			units.BytesSize(s.Memory), units.BytesSize(s.MemoryLimit),
-			s.MemoryPercentage,
-			units.HumanSizeWithPrecision(s.NetworkRx, 3), units.HumanSizeWithPrecision(s.NetworkTx, 3),
-			units.HumanSizeWithPrecision(s.BlockRead, 3), units.HumanSizeWithPrecision(s.BlockWrite, 3),
-			s.PidsCurrent)
-	}
-	return nil
-}
-
 func calculateCPUPercentUnix(previousCPU, previousSystem uint64, v *types.StatsJSON) float64 {
 	var (
 		cpuPercent = 0.0

command/container/stats_unit_test.go

@@ -1,36 +1,11 @@
 package container
 
 import (
-	"bytes"
 	"testing"
 
 	"github.com/docker/docker/api/types"
 )
 
-func TestDisplay(t *testing.T) {
-	c := &containerStats{
-		Name:             "app",
-		CPUPercentage:    30.0,
-		Memory:           100 * 1024 * 1024.0,
-		MemoryLimit:      2048 * 1024 * 1024.0,
-		MemoryPercentage: 100.0 / 2048.0 * 100.0,
-		NetworkRx:        100 * 1024 * 1024,
-		NetworkTx:        800 * 1024 * 1024,
-		BlockRead:        100 * 1024 * 1024,
-		BlockWrite:       800 * 1024 * 1024,
-		PidsCurrent:      1,
-	}
-	var b bytes.Buffer
-	if err := c.Display(&b); err != nil {
-		t.Fatalf("c.Display() gave error: %s", err)
-	}
-	got := b.String()
-	want := "app\t30.00%\t100 MiB / 2 GiB\t4.88%\t105 MB / 839 MB\t105 MB / 839 MB\t1\n"
-	if got != want {
-		t.Fatalf("c.Display() = %q, want %q", got, want)
-	}
-}
-
 func TestCalculBlockIO(t *testing.T) {
 	blkio := types.BlkioStats{
 		IoServiceBytesRecursive: []types.BlkioStatEntry{{8, 0, "read", 1234}, {8, 1, "read", 4567}, {8, 0, "write", 123}, {8, 1, "write", 456}},

command/formatter/stats.go

@@ -0,0 +1,135 @@
+package formatter
+
+import (
+	"fmt"
+	"sync"
+
+	"github.com/docker/go-units"
+)
+
+const (
+	defaultStatsTableFormat    = "table {{.Container}}\t{{.CPUPrec}}\t{{.MemUsage}}\t{{.MemPrec}}\t{{.NetIO}}\t{{.BlockIO}}\t{{.PIDs}}"
+	winDefaultStatsTableFormat = "table {{.Container}}\t{{.CPUPrec}}\t{{{.MemUsage}}\t{.NetIO}}\t{{.BlockIO}}"
+	emptyStatsTableFormat      = "Waiting for statistics..."
+
+	containerHeader  = "CONTAINER"
+	cpuPrecHeader    = "CPU %"
+	netIOHeader      = "NET I/O"
+	blockIOHeader    = "BLOCK I/O"
+	winMemPrecHeader = "PRIV WORKING SET"  // Used only on Window
+	memPrecHeader    = "MEM %"             // Used only on Linux
+	memUseHeader     = "MEM USAGE / LIMIT" // Used only on Linux
+	pidsHeader       = "PIDS"              // Used only on Linux
+)
+
+// ContainerStatsAttrs represents the statistics data collected from a container.
+type ContainerStatsAttrs struct {
+	Windows          bool
+	Name             string
+	CPUPercentage    float64
+	Memory           float64 // On Windows this is the private working set
+	MemoryLimit      float64 // Not used on Windows
+	MemoryPercentage float64 // Not used on Windows
+	NetworkRx        float64
+	NetworkTx        float64
+	BlockRead        float64
+	BlockWrite       float64
+	PidsCurrent      uint64 // Not used on Windows
+}
+
+// ContainerStats represents the containers statistics data.
+type ContainerStats struct {
+	Mu sync.RWMutex
+	ContainerStatsAttrs
+	Err error
+}
+
+// NewStatsFormat returns a format for rendering an CStatsContext
+func NewStatsFormat(source, osType string) Format {
+	if source == TableFormatKey {
+		if osType == "windows" {
+			return Format(winDefaultStatsTableFormat)
+		}
+		return Format(defaultStatsTableFormat)
+	}
+	return Format(source)
+}
+
+// NewContainerStats returns a new ContainerStats entity and sets in it the given name
+func NewContainerStats(name, osType string) *ContainerStats {
+	return &ContainerStats{
+		ContainerStatsAttrs: ContainerStatsAttrs{
+			Name:    name,
+			Windows: (osType == "windows"),
+		},
+	}
+}
+
+// ContainerStatsWrite renders the context for a list of containers statistics
+func ContainerStatsWrite(ctx Context, containerStats []*ContainerStats) error {
+	render := func(format func(subContext subContext) error) error {
+		for _, cstats := range containerStats {
+			cstats.Mu.RLock()
+			cstatsAttrs := cstats.ContainerStatsAttrs
+			cstats.Mu.RUnlock()
+			containerStatsCtx := &containerStatsContext{
+				s: cstatsAttrs,
+			}
+			if err := format(containerStatsCtx); err != nil {
+				return err
+			}
+		}
+		return nil
+	}
+	return ctx.Write(&containerStatsContext{}, render)
+}
+
+type containerStatsContext struct {
+	HeaderContext
+	s ContainerStatsAttrs
+}
+
+func (c *containerStatsContext) Container() string {
+	c.AddHeader(containerHeader)
+	return c.s.Name
+}
+
+func (c *containerStatsContext) CPUPrec() string {
+	c.AddHeader(cpuPrecHeader)
+	return fmt.Sprintf("%.2f%%", c.s.CPUPercentage)
+}
+
+func (c *containerStatsContext) MemUsage() string {
+	c.AddHeader(memUseHeader)
+	if !c.s.Windows {
+		return fmt.Sprintf("%s / %s", units.BytesSize(c.s.Memory), units.BytesSize(c.s.MemoryLimit))
+	}
+	return fmt.Sprintf("-- / --")
+}
+
+func (c *containerStatsContext) MemPrec() string {
+	header := memPrecHeader
+	if c.s.Windows {
+		header = winMemPrecHeader
+	}
+	c.AddHeader(header)
+	return fmt.Sprintf("%.2f%%", c.s.MemoryPercentage)
+}
+
+func (c *containerStatsContext) NetIO() string {
+	c.AddHeader(netIOHeader)
+	return fmt.Sprintf("%s / %s", units.HumanSizeWithPrecision(c.s.NetworkRx, 3), units.HumanSizeWithPrecision(c.s.NetworkTx, 3))
+}
+
+func (c *containerStatsContext) BlockIO() string {
+	c.AddHeader(blockIOHeader)
+	return fmt.Sprintf("%s / %s", units.HumanSizeWithPrecision(c.s.BlockRead, 3), units.HumanSizeWithPrecision(c.s.BlockWrite, 3))
+}
+
+func (c *containerStatsContext) PIDs() string {
+	c.AddHeader(pidsHeader)
+	if !c.s.Windows {
+		return fmt.Sprintf("%d", c.s.PidsCurrent)
+	}
+	return fmt.Sprintf("-")
+}