fixing a little bug when creating a builder without target flag on da…

…rwin

Signed-off-by: Juan Bustamante <jbustamante@vmware.com>

pkg/buildpack/downloader_test.go

@@ -10,6 +10,7 @@ import (
 
 	"github.com/buildpacks/imgutil/fakes"
 	"github.com/buildpacks/lifecycle/api"
+	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/api/types/system"
 	"github.com/golang/mock/gomock"
 	"github.com/heroku/color"
@@ -61,6 +62,7 @@ func testBuildpackDownloader(t *testing.T, when spec.G, it spec.S) {
 	var createPackage = func(imageName string) *fakes.Image {
 		packageImage := fakes.NewImage(imageName, "", nil)
 		mockImageFactory.EXPECT().NewImage(packageImage.Name(), false, dist.Target{OS: "linux"}).Return(packageImage, nil)
+		mockDockerClient.EXPECT().ServerVersion(gomock.Any()).Return(types.Version{Os: "linux", Arch: "amd64"}, nil)
 
 		pack, err := client.NewClient(
 			client.WithLogger(logger),

pkg/client/create_builder.go

@@ -363,19 +363,38 @@ func (c *Client) addConfig(ctx context.Context, kind string, config pubbldr.Modu
 
 func (c *Client) processBuilderCreateTargets(ctx context.Context, opts CreateBuilderOptions) ([]dist.Target, error) {
 	var targets []dist.Target
-	if len(opts.Targets) > 0 {
-		// when exporting to the daemon, we need to select just one target
-		if !opts.Publish {
-			daemonTarget, err := c.daemonTarget(ctx, opts.Targets)
+
+	// For backward compatibility, we must create a target with de default platform used in the Fetch implementation for daemon and remote
+	// When daemon
+	//		OS:           daemonInfo.Os,
+	//		Architecture: daemonInfo.Arch
+	// When remote || layout
+	// 		OS:           "linux",
+	//		Architecture: runtime.GOARCH
+
+	if !opts.Publish {
+		// daemon option
+		info, err := c.docker.ServerVersion(ctx)
+		if err != nil {
+			return targets, err
+		}
+		if len(opts.Targets) > 0 {
+			// when exporting to the daemon, we need to select just one target
+			daemonTarget, err := c.daemonTarget(info, opts.Targets)
 			if err != nil {
 				return targets, err
 			}
 			targets = append(targets, daemonTarget)
 		} else {
-			targets = opts.Targets
+			targets = append(targets, dist.Target{OS: info.Os, Arch: info.Arch})
 		}
 	} else {
-		targets = append(targets, dist.Target{OS: runtime.GOOS, Arch: runtime.GOARCH})
+		// remote option
+		if len(opts.Targets) > 0 {
+			targets = opts.Targets
+		} else {
+			targets = append(targets, dist.Target{OS: "linux", Arch: runtime.GOARCH})
+		}
 	}
 	return targets, nil
 }

pkg/client/package_buildpack.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"path/filepath"
 
+	"github.com/docker/docker/api/types"
 	"github.com/pkg/errors"
 
 	pubbldpkg "github.com/buildpacks/pack/buildpackage"
@@ -228,10 +229,14 @@ func (c *Client) downloadBuildpackFromURI(ctx context.Context, uri, relativeBase
 
 func (c *Client) processPackageBuildpackTargets(ctx context.Context, opts PackageBuildpackOptions) ([]dist.Target, error) {
 	var targets []dist.Target
+	info, err := c.docker.ServerVersion(ctx)
+	if err != nil {
+		return targets, err
+	}
 	if len(opts.Targets) > 0 {
 		// when exporting to the daemon, we need to select just one target
 		if !opts.Publish && opts.Format == FormatImage {
-			daemonTarget, err := c.daemonTarget(ctx, opts.Targets)
+			daemonTarget, err := c.daemonTarget(info, opts.Targets)
 			if err != nil {
 				return targets, err
 			}
@@ -262,12 +267,8 @@ func (c *Client) validateOSPlatform(ctx context.Context, os string, publish bool
 	return nil
 }
 
-func (c *Client) daemonTarget(ctx context.Context, targets []dist.Target) (dist.Target, error) {
-	info, err := c.docker.ServerVersion(ctx)
-	if err != nil {
-		return dist.Target{}, err
-	}
-
+// daemonTarget returns a target that matches with the given daemon os/arch
+func (c *Client) daemonTarget(info types.Version, targets []dist.Target) (dist.Target, error) {
 	for _, t := range targets {
 		if t.Arch != "" && t.OS == info.Os && t.Arch == info.Arch {
 			return t, nil