image/list: Add `--tree` flag

Signed-off-by: Paweł Gronowski <pawel.gronowski@docker.com>

cli/command/image/list.go

@@ -2,6 +2,7 @@ package image
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"io"
 
@@ -24,6 +25,7 @@ type imagesOptions struct {
 	format      string
 	filter      opts.FilterOpt
 	calledAs    string
+	tree        bool
 }
 
 // NewImagesCommand creates a new `docker images` command
@@ -59,6 +61,10 @@ func NewImagesCommand(dockerCLI command.Cli) *cobra.Command {
 	flags.StringVar(&options.format, "format", "", flagsHelper.FormatHelp)
 	flags.VarP(&options.filter, "filter", "f", "Filter output based on conditions provided")
 
+	flags.BoolVar(&options.tree, "tree", false, "List multi-platform images as a tree (EXPERIMENTAL)")
+	flags.SetAnnotation("tree", "version", []string{"1.47"})
+	flags.SetAnnotation("tree", "experimentalCLI", nil)
+
 	return cmd
 }
 
@@ -75,6 +81,26 @@ func runImages(ctx context.Context, dockerCLI command.Cli, options imagesOptions
 		filters.Add("reference", options.matchName)
 	}
 
+	if options.tree {
+		if options.quiet {
+			return errors.New("--quiet is not yet supported with --tree")
+		}
+		if options.noTrunc {
+			return errors.New("--no-trunc is not yet supported with --tree")
+		}
+		if options.showDigests {
+			return errors.New("--show-digest is not yet supported with --tree")
+		}
+		if options.format != "" {
+			return errors.New("--format is not yet supported with --tree")
+		}
+
+		return runTree(ctx, dockerCLI, treeOptions{
+			all:     options.all,
+			filters: filters,
+		})
+	}
+
 	images, err := dockerCLI.Client().ImageList(ctx, image.ListOptions{
 		All:     options.all,
 		Filters: filters,

cli/command/image/tree.go

@@ -0,0 +1,312 @@
+package image
+
+import (
+	"context"
+	"fmt"
+	"strings"
+	"unicode/utf8"
+
+	"github.com/containerd/platforms"
+	"github.com/docker/cli/cli/command"
+	"github.com/docker/cli/cli/streams"
+	"github.com/docker/docker/api/types/filters"
+	imagetypes "github.com/docker/docker/api/types/image"
+	"github.com/docker/docker/pkg/stringid"
+	"github.com/docker/go-units"
+	"github.com/morikuni/aec"
+)
+
+type treeOptions struct {
+	all     bool
+	filters filters.Args
+}
+
+func runTree(ctx context.Context, dockerCLI command.Cli, opts treeOptions) error {
+	images, err := dockerCLI.Client().ImageList(ctx, imagetypes.ListOptions{
+		All:       opts.all,
+		Filters:   opts.filters,
+		Manifests: true,
+	})
+	if err != nil {
+		return err
+	}
+
+	view := make([]topImage, 0, len(images))
+	for _, img := range images {
+		details := imageDetails{
+			ID:        img.ID,
+			DiskUsage: units.HumanSizeWithPrecision(float64(img.Size), 3),
+			Used:      img.Containers > 0,
+		}
+
+		children := make([]subImage, 0, len(img.Manifests))
+		for _, im := range img.Manifests {
+			if im.Kind != imagetypes.ManifestKindImage {
+				continue
+			}
+
+			sub := subImage{
+				Platform:  platforms.Format(im.ImageData.Platform),
+				Available: im.Available,
+				Details: imageDetails{
+					ID:        im.ID,
+					DiskUsage: units.HumanSizeWithPrecision(float64(im.Size.Total), 3),
+					Used:      len(im.ImageData.Containers) > 0,
+				},
+			}
+
+			children = append(children, sub)
+		}
+
+		view = append(view, topImage{
+			Names:    img.RepoTags,
+			Details:  details,
+			Children: children,
+		})
+	}
+
+	return printImageTree(dockerCLI, view)
+}
+
+type imageDetails struct {
+	ID        string
+	DiskUsage string
+	Used      bool
+}
+
+type topImage struct {
+	Names    []string
+	Details  imageDetails
+	Children []subImage
+}
+
+type subImage struct {
+	Platform  string
+	Available bool
+	Details   imageDetails
+}
+
+const columnSpacing = 3
+
+func printImageTree(dockerCLI command.Cli, images []topImage) error {
+	out := dockerCLI.Out()
+	_, width := out.GetTtySize()
+	if width == 0 {
+		width = 80
+	}
+	if width < 20 {
+		width = 20
+	}
+
+	headerColor := aec.NewBuilder(aec.DefaultF, aec.Bold).ANSI
+	topNameColor := aec.NewBuilder(aec.BlueF, aec.Underline, aec.Bold).ANSI
+	normalColor := aec.NewBuilder(aec.DefaultF).ANSI
+	greenColor := aec.NewBuilder(aec.GreenF).ANSI
+	if !out.IsTerminal() {
+		headerColor = noColor{}
+		topNameColor = noColor{}
+		normalColor = noColor{}
+		greenColor = noColor{}
+	}
+
+	columns := []imgColumn{
+		{Title: "Image", Width: 0, Left: true},
+		{
+			Title: "ID",
+			Width: 12,
+			DetailsValue: func(d *imageDetails) string {
+				return stringid.TruncateID(d.ID)
+			},
+		},
+		{
+			Title: "Disk usage",
+			Width: 10,
+			DetailsValue: func(d *imageDetails) string {
+				return d.DiskUsage
+			},
+		},
+		{
+			Title: "Used",
+			Width: 4,
+			Color: &greenColor,
+			DetailsValue: func(d *imageDetails) string {
+				if d.Used {
+					return "✔"
+				}
+				return " "
+			},
+		},
+	}
+
+	nameWidth := int(width)
+	for idx, h := range columns {
+		if h.Width == 0 {
+			continue
+		}
+		d := h.Width
+		if idx > 0 {
+			d += columnSpacing
+		}
+		// If the first column gets too short, remove remaining columns
+		if nameWidth-d < 12 {
+			columns = columns[:idx]
+			break
+		}
+		nameWidth -= d
+	}
+
+	// Try to make the first column as narrow as possible
+	widest := widestFirstColumnValue(columns, images)
+	if nameWidth > widest {
+		nameWidth = widest
+	}
+	columns[0].Width = nameWidth
+
+	// Print columns
+	for i, h := range columns {
+		if i > 0 {
+			_, _ = fmt.Fprint(out, strings.Repeat(" ", columnSpacing))
+		}
+
+		_, _ = fmt.Fprint(out, h.Print(headerColor, h.Title))
+	}
+
+	_, _ = fmt.Fprintln(out)
+
+	// Print images
+	for idx, img := range images {
+		if idx != 0 {
+			_, _ = fmt.Fprintln(out, "")
+		}
+
+		printNames(out, columns, img, topNameColor)
+		printDetails(out, columns, normalColor, img.Details)
+		printChildren(out, columns, img, normalColor)
+	}
+
+	return nil
+}
+
+func printDetails(out *streams.Out, headers []imgColumn, defaultColor aec.ANSI, details imageDetails) {
+	for _, h := range headers {
+		if h.DetailsValue == nil {
+			continue
+		}
+
+		_, _ = fmt.Fprint(out, strings.Repeat(" ", columnSpacing))
+		clr := defaultColor
+		if h.Color != nil {
+			clr = *h.Color
+		}
+		val := h.DetailsValue(&details)
+		_, _ = fmt.Fprint(out, h.Print(clr, val))
+	}
+	fmt.Printf("\n")
+}
+
+func printChildren(out *streams.Out, headers []imgColumn, img topImage, normalColor aec.ANSI) {
+	for idx, sub := range img.Children {
+		clr := normalColor
+		if !sub.Available {
+			clr = normalColor.With(aec.Faint)
+		}
+
+		if idx != len(img.Children)-1 {
+			_, _ = fmt.Fprint(out, headers[0].Print(clr, "├─ "+sub.Platform))
+		} else {
+			_, _ = fmt.Fprint(out, headers[0].Print(clr, "└─ "+sub.Platform))
+		}
+
+		printDetails(out, headers, clr, sub.Details)
+	}
+}
+
+func printNames(out *streams.Out, headers []imgColumn, img topImage, color aec.ANSI) {
+	for nameIdx, name := range img.Names {
+		if nameIdx != 0 {
+			_, _ = fmt.Fprintln(out, "")
+		}
+		_, _ = fmt.Fprint(out, headers[0].Print(color, name))
+	}
+}
+
+type imgColumn struct {
+	Title string
+	Width int
+	Left  bool
+
+	DetailsValue func(*imageDetails) string
+	Color        *aec.ANSI
+}
+
+func truncateRunes(s string, length int) string {
+	runes := []rune(s)
+	if len(runes) > length {
+		return string(runes[:length-3]) + "..."
+	}
+	return s
+}
+
+func (h imgColumn) Print(clr aec.ANSI, s string) (out string) {
+	if h.Left {
+		return h.PrintL(clr, s)
+	}
+	return h.PrintC(clr, s)
+}
+
+func (h imgColumn) PrintC(clr aec.ANSI, s string) (out string) {
+	ln := utf8.RuneCountInString(s)
+
+	if ln > h.Width {
+		return clr.Apply(truncateRunes(s, h.Width))
+	}
+
+	fill := h.Width - ln
+
+	l := fill / 2
+	r := fill - l
+
+	return strings.Repeat(" ", l) + clr.Apply(s) + strings.Repeat(" ", r)
+}
+
+func (h imgColumn) PrintL(clr aec.ANSI, s string) string {
+	ln := utf8.RuneCountInString(s)
+	if ln > h.Width {
+		return clr.Apply(truncateRunes(s, h.Width))
+	}
+
+	return clr.Apply(s) + strings.Repeat(" ", h.Width-ln)
+}
+
+type noColor struct{}
+
+func (a noColor) With(ansi ...aec.ANSI) aec.ANSI {
+	return aec.NewBuilder(ansi...).ANSI
+}
+
+func (a noColor) Apply(s string) string {
+	return s
+}
+
+func (a noColor) String() string {
+	return ""
+}
+
+// widestFirstColumnValue calculates the width needed to fully display the image names and platforms.
+func widestFirstColumnValue(headers []imgColumn, images []topImage) int {
+	width := len(headers[0].Title)
+	for _, img := range images {
+		for _, name := range img.Names {
+			if len(name) > width {
+				width = len(name)
+			}
+		}
+		for _, sub := range img.Children {
+			pl := len(sub.Platform) + len("└─ ")
+			if pl > width {
+				width = pl
+			}
+		}
+	}
+	return width
+}

docs/reference/commandline/image_ls.md

@@ -17,6 +17,7 @@ List images
 | [`--format`](#format)                  | `string` |         | Format output using a custom template:<br>'table':            Print output in table format with column headers (default)<br>'table TEMPLATE':   Print output in table format using the given Go template<br>'json':             Print in JSON format<br>'TEMPLATE':         Print output using the given Go template.<br>Refer to https://docs.docker.com/go/formatting/ for more information about formatting output with templates |
 | [`--no-trunc`](#no-trunc)              | `bool`   |         | Don't truncate output                                                                                                                                                                                                                                                                                                                                                                                                                |
 | `-q`, `--quiet`                        | `bool`   |         | Only show image IDs                                                                                                                                                                                                                                                                                                                                                                                                                  |
+| `--tree`                               | `bool`   |         | List multi-platform images as a tree (EXPERIMENTAL)                                                                                                                                                                                                                                                                                                                                                                                  |
 
 
 <!---MARKER_GEN_END-->

docs/reference/commandline/images.md

@@ -17,6 +17,7 @@ List images
 | `--format`       | `string` |         | Format output using a custom template:<br>'table':            Print output in table format with column headers (default)<br>'table TEMPLATE':   Print output in table format using the given Go template<br>'json':             Print in JSON format<br>'TEMPLATE':         Print output using the given Go template.<br>Refer to https://docs.docker.com/go/formatting/ for more information about formatting output with templates |
 | `--no-trunc`     | `bool`   |         | Don't truncate output                                                                                                                                                                                                                                                                                                                                                                                                                |
 | `-q`, `--quiet`  | `bool`   |         | Only show image IDs                                                                                                                                                                                                                                                                                                                                                                                                                  |
+| `--tree`         | `bool`   |         | List multi-platform images as a tree (EXPERIMENTAL)                                                                                                                                                                                                                                                                                                                                                                                  |
 
 
 <!---MARKER_GEN_END-->