LCOW: Add `--platform=` CLI flag to pull/create/run/build

Signed-off-by: John Howard <jhoward@microsoft.com>

This is the CLI updates for the document discussed in https://github.com/moby/moby/issues/34617
to support Linux Containers on Windows. It adds --platform= as CLI flags to the four
commands listed above. Import still to be completed (needs daemon changes).

cli/command/container/create.go

@@ -21,7 +21,8 @@ import (
 )
 
 type createOptions struct {
-	name string
+	name     string
+	platform string
 }
 
 // NewCreateCommand creates a new cobra.Command for `docker create`
@@ -51,6 +52,7 @@ func NewCreateCommand(dockerCli command.Cli) *cobra.Command {
 	// with hostname
 	flags.Bool("help", false, "Print usage")
 
+	command.AddPlatformFlag(flags, &opts.platform)
 	command.AddTrustVerificationFlags(flags)
 	copts = addFlags(flags)
 	return cmd
@@ -62,7 +64,7 @@ func runCreate(dockerCli command.Cli, flags *pflag.FlagSet, opts *createOptions,
 		reportError(dockerCli.Err(), "create", err.Error(), true)
 		return cli.StatusError{StatusCode: 125}
 	}
-	response, err := createContainer(context.Background(), dockerCli, containerConfig, opts.name)
+	response, err := createContainer(context.Background(), dockerCli, containerConfig, opts.name, opts.platform)
 	if err != nil {
 		return err
 	}
@@ -70,7 +72,7 @@ func runCreate(dockerCli command.Cli, flags *pflag.FlagSet, opts *createOptions,
 	return nil
 }
 
-func pullImage(ctx context.Context, dockerCli command.Cli, image string, out io.Writer) error {
+func pullImage(ctx context.Context, dockerCli command.Cli, image string, platform string, out io.Writer) error {
 	ref, err := reference.ParseNormalizedNamed(image)
 	if err != nil {
 		return err
@@ -90,6 +92,7 @@ func pullImage(ctx context.Context, dockerCli command.Cli, image string, out io.
 
 	options := types.ImageCreateOptions{
 		RegistryAuth: encodedAuth,
+		Platform:     platform,
 	}
 
 	responseBody, err := dockerCli.Client().ImageCreate(ctx, image, options)
@@ -155,7 +158,7 @@ func newCIDFile(path string) (*cidFile, error) {
 	return &cidFile{path: path, file: f}, nil
 }
 
-func createContainer(ctx context.Context, dockerCli command.Cli, containerConfig *containerConfig, name string) (*container.ContainerCreateCreatedBody, error) {
+func createContainer(ctx context.Context, dockerCli command.Cli, containerConfig *containerConfig, name string, platform string) (*container.ContainerCreateCreatedBody, error) {
 	config := containerConfig.Config
 	hostConfig := containerConfig.HostConfig
 	networkingConfig := containerConfig.NetworkingConfig
@@ -198,7 +201,7 @@ func createContainer(ctx context.Context, dockerCli command.Cli, containerConfig
 			fmt.Fprintf(stderr, "Unable to find image '%s' locally\n", reference.FamiliarString(namedRef))
 
 			// we don't want to write to stdout anything apart from container.ID
-			if err := pullImage(ctx, dockerCli, config.Image, stderr); err != nil {
+			if err := pullImage(ctx, dockerCli, config.Image, platform, stderr); err != nil {
 				return nil, err
 			}
 			if taggedRef, ok := namedRef.(reference.NamedTagged); ok && trustedRef != nil {

cli/command/container/create_test.go

@@ -5,6 +5,7 @@ import (
 	"io"
 	"io/ioutil"
 	"os"
+	"runtime"
 	"strings"
 	"testing"
 
@@ -106,7 +107,7 @@ func TestCreateContainerPullsImageIfMissing(t *testing.T) {
 		},
 		HostConfig: &container.HostConfig{},
 	}
-	body, err := createContainer(context.Background(), cli, config, "name")
+	body, err := createContainer(context.Background(), cli, config, "name", runtime.GOOS)
 	require.NoError(t, err)
 	expected := container.ContainerCreateCreatedBody{ID: containerID}
 	assert.Equal(t, expected, *body)

cli/command/container/run.go

@@ -29,6 +29,7 @@ type runOptions struct {
 	sigProxy   bool
 	name       string
 	detachKeys string
+	platform   string
 }
 
 // NewRunCommand create a new `docker run` command
@@ -62,6 +63,7 @@ func NewRunCommand(dockerCli command.Cli) *cobra.Command {
 	// with hostname
 	flags.Bool("help", false, "Print usage")
 
+	command.AddPlatformFlag(flags, &opts.platform)
 	command.AddTrustVerificationFlags(flags)
 	copts = addFlags(flags)
 	return cmd
@@ -160,7 +162,7 @@ func runContainer(dockerCli command.Cli, opts *runOptions, copts *containerOptio
 
 	ctx, cancelFun := context.WithCancel(context.Background())
 
-	createResponse, err := createContainer(ctx, dockerCli, containerConfig, opts.name)
+	createResponse, err := createContainer(ctx, dockerCli, containerConfig, opts.name, opts.platform)
 	if err != nil {
 		reportError(stderr, cmdPath, err.Error(), true)
 		return runStartContainerErr(err)

cli/command/image/build.go

@@ -64,6 +64,7 @@ type buildOptions struct {
 	target         string
 	imageIDFile    string
 	stream         bool
+	platform       string
 }
 
 // dockerfileFromStdin returns true when the user specified that the Dockerfile
@@ -135,6 +136,7 @@ func NewBuildCommand(dockerCli command.Cli) *cobra.Command {
 	flags.StringVar(&options.imageIDFile, "iidfile", "", "Write the image ID to the file")
 
 	command.AddTrustVerificationFlags(flags)
+	command.AddPlatformFlag(flags, &options.platform)
 
 	flags.BoolVar(&options.squash, "squash", false, "Squash newly built layers into a single new layer")
 	flags.SetAnnotation("squash", "experimental", nil)
@@ -374,6 +376,7 @@ func runBuild(dockerCli command.Cli, options buildOptions) error {
 		ExtraHosts:     options.extraHosts.GetAll(),
 		Target:         options.target,
 		RemoteContext:  remote,
+		Platform:       options.platform,
 	}
 
 	if s != nil {

cli/command/image/pull.go

@@ -14,8 +14,9 @@ import (
 )
 
 type pullOptions struct {
-	remote string
+	remote   string
-	all    bool
+	all      bool
+	platform string
 }
 
 // NewPullCommand creates a new `docker pull` command
@@ -35,6 +36,8 @@ func NewPullCommand(dockerCli command.Cli) *cobra.Command {
 	flags := cmd.Flags()
 
 	flags.BoolVarP(&opts.all, "all-tags", "a", false, "Download all tagged images in the repository")
+
+	command.AddPlatformFlag(flags, &opts.platform)
 	command.AddTrustVerificationFlags(flags)
 
 	return cmd
@@ -63,9 +66,9 @@ func runPull(cli command.Cli, opts pullOptions) error {
 	// Check if reference has a digest
 	_, isCanonical := distributionRef.(reference.Canonical)
 	if command.IsTrusted() && !isCanonical {
-		err = trustedPull(ctx, cli, imgRefAndAuth)
+		err = trustedPull(ctx, cli, imgRefAndAuth, opts.platform)
 	} else {
-		err = imagePullPrivileged(ctx, cli, imgRefAndAuth, opts.all)
+		err = imagePullPrivileged(ctx, cli, imgRefAndAuth, opts.all, opts.platform)
 	}
 	if err != nil {
 		if strings.Contains(err.Error(), "when fetching 'plugin'") {

cli/command/image/trust.go

@@ -180,7 +180,7 @@ func imagePushPrivileged(ctx context.Context, cli command.Cli, authConfig types.
 }
 
 // trustedPull handles content trust pulling of an image
-func trustedPull(ctx context.Context, cli command.Cli, imgRefAndAuth trust.ImageRefAndAuth) error {
+func trustedPull(ctx context.Context, cli command.Cli, imgRefAndAuth trust.ImageRefAndAuth, platform string) error {
 	refs, err := getTrustedPullTargets(cli, imgRefAndAuth)
 	if err != nil {
 		return err
@@ -202,7 +202,7 @@ func trustedPull(ctx context.Context, cli command.Cli, imgRefAndAuth trust.Image
 		if err != nil {
 			return err
 		}
-		if err := imagePullPrivileged(ctx, cli, updatedImgRefAndAuth, false); err != nil {
+		if err := imagePullPrivileged(ctx, cli, updatedImgRefAndAuth, false, platform); err != nil {
 			return err
 		}
 
@@ -268,7 +268,7 @@ func getTrustedPullTargets(cli command.Cli, imgRefAndAuth trust.ImageRefAndAuth)
 }
 
 // imagePullPrivileged pulls the image and displays it to the output
-func imagePullPrivileged(ctx context.Context, cli command.Cli, imgRefAndAuth trust.ImageRefAndAuth, all bool) error {
+func imagePullPrivileged(ctx context.Context, cli command.Cli, imgRefAndAuth trust.ImageRefAndAuth, all bool, platform string) error {
 	ref := reference.FamiliarString(imgRefAndAuth.Reference())
 
 	encodedAuth, err := command.EncodeAuthToBase64(*imgRefAndAuth.AuthConfig())
@@ -280,8 +280,8 @@ func imagePullPrivileged(ctx context.Context, cli command.Cli, imgRefAndAuth tru
 		RegistryAuth:  encodedAuth,
 		PrivilegeFunc: requestPrivilege,
 		All:           all,
+		Platform:      platform,
 	}
-
 	responseBody, err := cli.Client().ImagePull(ctx, ref, options)
 	if err != nil {
 		return err

cli/command/utils.go

@@ -11,6 +11,7 @@ import (
 
 	"github.com/docker/docker/api/types/filters"
 	"github.com/docker/docker/pkg/system"
+	"github.com/spf13/pflag"
 )
 
 // CopyToFile writes the content of the reader to the specified file
@@ -117,3 +118,10 @@ func PruneFilters(dockerCli Cli, pruneFilters filters.Args) filters.Args {
 
 	return pruneFilters
 }
+
+// AddPlatformFlag adds `platform` to a set of flags for API version 1.32 and later.
+func AddPlatformFlag(flags *pflag.FlagSet, target *string) {
+	flags.StringVar(target, "platform", os.Getenv("DOCKER_DEFAULT_PLATFORM"), "Set platform if server is multi-platform capable")
+	flags.SetAnnotation("platform", "version", []string{"1.32"})
+	flags.SetAnnotation("platform", "experimental", nil)
+}