image: Add convert command

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

Author: vvoland

cli/command/image/cmd.go

@@ -27,6 +27,7 @@ func NewImageCommand(dockerCli command.Cli) *cobra.Command {
 		newRemoveCommand(dockerCli),
 		newInspectCommand(dockerCli),
 		NewPruneCommand(dockerCli),
+		NewConvertCommand(dockerCli),
 	)
 	return cmd
 }

cli/command/image/convert.go

@@ -0,0 +1,80 @@
+package image
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/containerd/platforms"
+	"github.com/distribution/reference"
+	"github.com/docker/cli/cli"
+	"github.com/docker/cli/cli/command"
+	imagetypes "github.com/docker/docker/api/types/image"
+	"github.com/spf13/cobra"
+)
+
+type convertArgs struct {
+	Src                    string
+	Dst                    []string
+	Platforms              []string
+	NoAttestations         bool
+	OnlyAvailablePlatforms bool
+}
+
+func NewConvertCommand(dockerCli command.Cli) *cobra.Command {
+	var args convertArgs
+
+	cmd := &cobra.Command{
+		Use:   "convert [OPTIONS] <from>",
+		Short: "Convert multi-platform images",
+		Args:  cli.ExactArgs(1),
+		RunE: func(cmd *cobra.Command, posArgs []string) error {
+			args.Src = posArgs[0]
+			return runConvert(cmd.Context(), dockerCli, args)
+		},
+		Aliases: []string{"convert"},
+		Annotations: map[string]string{
+			"aliases": "docker image convert, docker convert",
+		},
+	}
+
+	flags := cmd.Flags()
+	flags.StringArrayVar(&args.Platforms, "platforms", nil, "Include only the specified platforms in the destination image")
+	flags.BoolVar(&args.NoAttestations, "no-attestations", false, "Do not include image attestations")
+	flags.BoolVar(&args.OnlyAvailablePlatforms, "available", false, "Only include platforms locally available to the daemon")
+	flags.StringArrayVar(&args.Dst, "to", nil, "Target image references")
+
+	return cmd
+}
+
+func runConvert(ctx context.Context, dockerCLI command.Cli, args convertArgs) error {
+	if len(args.Dst) == 0 {
+		return fmt.Errorf("No destination image specified")
+	}
+
+	var dstRefs []reference.NamedTagged
+	for _, dst := range args.Dst {
+		dstRef, err := reference.ParseNormalizedNamed(dst)
+		if err != nil {
+			return fmt.Errorf("invalid destination image reference: %s: %w", dst, err)
+		}
+
+		dstRef = reference.TagNameOnly(dstRef)
+		dstRefTagged := dstRef.(reference.NamedTagged)
+		dstRefs = append(dstRefs, dstRefTagged)
+	}
+
+	opts := imagetypes.ConvertOptions{
+		NoAttestations:         args.NoAttestations,
+		OnlyAvailablePlatforms: args.OnlyAvailablePlatforms,
+	}
+
+	for _, platform := range args.Platforms {
+		p, err := platforms.Parse(platform)
+		if err != nil {
+			return err
+		}
+		opts.Platforms = append(opts.Platforms, p)
+	}
+
+	return dockerCLI.Client().ImageConvert(ctx, args.Src, dstRefs, opts)
+}

vendor.mod

@@ -9,6 +9,7 @@ go 1.21
 require (
 	dario.cat/mergo v1.0.0
 	github.com/containerd/containerd v1.7.14
+	github.com/containerd/platforms v0.1.1
 	github.com/creack/pty v1.1.21
 	github.com/distribution/reference v0.5.0
 	github.com/docker/distribution v2.8.3+incompatible

vendor.sum

@@ -43,6 +43,8 @@ github.com/containerd/containerd v1.7.14 h1:H/XLzbnGuenZEGK+v0RkwTdv2u1QFAruMe5N
 github.com/containerd/containerd v1.7.14/go.mod h1:YMC9Qt5yzNqXx/fO4j/5yYVIHXSRrlB3H7sxkUTvspg=
 github.com/containerd/log v0.1.0 h1:TCJt7ioM2cr/tfR8GPbGf9/VRAX8D2B4PjzCpfX540I=
 github.com/containerd/log v0.1.0/go.mod h1:VRRf09a7mHDIRezVKTRCrOq78v577GXq3bSa3EhrzVo=
+github.com/containerd/platforms v0.1.1 h1:gp0xXBoY+1CjH54gJDon0kBjIbK2C4XSX1BGwP5ptG0=
+github.com/containerd/platforms v0.1.1/go.mod h1:XOM2BS6kN6gXafPLg80V6y/QUib+xoLyC3qVmHzibko=
 github.com/coreos/go-systemd/v22 v22.3.2/go.mod h1:Y58oyj3AT4RCenI/lSvhwexgC+NSVTIJ3seZv2GcEnc=
 github.com/cpuguy83/go-md2man/v2 v2.0.3/go.mod h1:tgQtvFlXSQOSOSIRvRPT7W67SCa46tRHOmNcaadrF8o=
 github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=