builder: conditional warning for wcow

Signed-off-by: CrazyMax <crazy-max@users.noreply.github.com>

cli/command/image/build.go

@@ -34,10 +34,7 @@ import (
 	"github.com/spf13/cobra"
 )
 
-var (
-	errStdinConflict  = errors.New("invalid argument: can't use stdin for both build context and dockerfile")
-	warnLegacyBuilder string
-)
+var errStdinConflict = errors.New("invalid argument: can't use stdin for both build context and dockerfile")
 
 type buildOptions struct {
 	context        string
@@ -107,11 +104,6 @@ func NewBuildCommand(dockerCli command.Cli) *cobra.Command {
 		Args:  cli.ExactArgs(1),
 		RunE: func(cmd *cobra.Command, args []string) error {
 			options.context = args[0]
-			cmd.VisitParents(func(cmd *cobra.Command) {
-				if v, ok := cmd.Annotations["_warning_legacy_builder"]; ok {
-					warnLegacyBuilder = v
-				}
-			})
 			return runBuild(dockerCli, options)
 		},
 	}
@@ -192,10 +184,6 @@ func runBuild(dockerCli command.Cli, options buildOptions) error {
 		remote        string
 	)
 
-	if warnLegacyBuilder != "" && !options.quiet && dockerCli.ServerInfo().OSType != "windows" {
-		_, _ = fmt.Fprint(dockerCli.Err(), warnLegacyBuilder)
-	}
-
 	if options.stream {
 		_, _ = fmt.Fprint(dockerCli.Err(), `DEPRECATED: The experimental --stream flag has been removed and the build context
             will be sent non-streaming. Enable BuildKit instead with DOCKER_BUILDKIT=1

cmd/docker/builder.go

@@ -16,7 +16,6 @@ const (
 	buildxMissingWarning = `DEPRECATED: The legacy builder is deprecated and will be removed in a future release.
             Install the buildx component to build images with BuildKit:
             https://docs.docker.com/go/buildx/
-
 `
 
 	buildxMissingError = `ERROR: BuildKit is enabled but the buildx component is missing or broken.
@@ -75,8 +74,10 @@ func processBuilder(dockerCli command.Cli, cmd *cobra.Command, args, osargs []st
 	}
 
 	if useLegacy {
-		// set warning msg as annotation that will be displayed in build cmd
-		cmd.Annotations["_warning_legacy_builder"] = newBuilderError(true, nil).Error()
+		// display warning if not wcow and continue
+		if dockerCli.ServerInfo().OSType != "windows" {
+			_, _ = fmt.Fprintln(dockerCli.Err(), newBuilderError(true, nil))
+		}
 		return args, osargs, nil
 	}
 
@@ -90,8 +91,8 @@ func processBuilder(dockerCli command.Cli, cmd *cobra.Command, args, osargs []st
 		if useBuilder {
 			return args, osargs, newBuilderError(false, perr)
 		}
-		// otherwise, set the warning msg as annotation that will be displayed in build cmd
-		cmd.Annotations["_warning_legacy_builder"] = newBuilderError(true, perr).Error()
+		// otherwise, display warning and continue
+		_, _ = fmt.Fprintln(dockerCli.Err(), newBuilderError(true, perr))
 		return args, osargs, nil
 	}
 

cmd/docker/builder_test.go

@@ -68,7 +68,7 @@ func TestBuildkitDisabled(t *testing.T) {
 	assert.NilError(t, err)
 	assert.DeepEqual(t, []string{"build", "."}, args)
 
-	output.Assert(t, cmd.Annotations["_warning_legacy_builder"], map[int]func(string) error{
+	output.Assert(t, b.String(), map[int]func(string) error{
 		0: output.Suffix("DEPRECATED: The legacy builder is deprecated and will be removed in a future release."),
 	})
 }
@@ -95,7 +95,7 @@ func TestBuilderBroken(t *testing.T) {
 	assert.NilError(t, err)
 	assert.DeepEqual(t, []string{"build", "."}, args)
 
-	output.Assert(t, cmd.Annotations["_warning_legacy_builder"], map[int]func(string) error{
+	output.Assert(t, b.String(), map[int]func(string) error{
 		0: output.Prefix("failed to fetch metadata:"),
 		2: output.Suffix("DEPRECATED: The legacy builder is deprecated and will be removed in a future release."),
 	})

e2e/image/build_test.go

@@ -40,7 +40,6 @@ func TestBuildFromContextDirectoryWithTag(t *testing.T) {
 	const buildxMissingWarning = `DEPRECATED: The legacy builder is deprecated and will be removed in a future release.
             Install the buildx component to build images with BuildKit:
             https://docs.docker.com/go/buildx/
-
 `
 
 	result.Assert(t, icmd.Expected{Err: buildxMissingWarning})