Allow CustomBuilders and Builders to create windows builder images

hack/lifecycle/main.go

@@ -15,6 +15,7 @@ import (
 	"regexp"
 	"time"
 
+	"github.com/buildpacks/imgutil/layer"
 	"github.com/google/go-containerregistry/pkg/authn"
 	v1 "github.com/google/go-containerregistry/pkg/v1"
 	"github.com/google/go-containerregistry/pkg/v1/mutate"
@@ -41,10 +42,11 @@ func main() {
 	flag.Parse()
 
 	image, err := lifecycleImage(
-		"https://github.com/buildpacks/lifecycle/releases/download/v0.9.2/lifecycle-v0.9.2+linux.x86-64.tgz",
+		"https://github.com/buildpacks/lifecycle/releases/download/v0.9.3/lifecycle-v0.9.3+linux.x86-64.tgz",
+		"https://github.com/buildpacks/lifecycle/releases/download/v0.9.3/lifecycle-v0.9.3+windows.x86-64.tgz",
 		cnb.LifecycleMetadata{
 			LifecycleInfo: cnb.LifecycleInfo{
-				Version: "0.9.2",
+				Version: "0.9.3",
 			},
 			API: cnb.LifecycleAPI{
 				BuildpackVersion: "0.2",
@@ -75,18 +77,42 @@ func main() {
 
 }
 
-func lifecycleImage(url string, lifecycleMetadata cnb.LifecycleMetadata) (v1.Image, error) {
+func lifecycleImage(linuxUrl, windowsUrl string, lifecycleMetadata cnb.LifecycleMetadata) (v1.Image, error) {
 	image, err := random.Image(0, 0)
 	if err != nil {
 		return nil, err
 	}
 
-	layer, err := lifecycleLayer(url)
+	linuxLayer, err := lifecycleLayer(linuxUrl, "linux")
+	if err != nil {
+		return nil, err
+	}
+	linuxDiffID, err := linuxLayer.DiffID()
+	if err != nil {
+		return nil, err
+	}
+
+	image, err = imagehelpers.SetStringLabel(image, "linux", linuxDiffID.String())
+	if err != nil {
+		return nil, err
+	}
+
+	windowsLayer, err := lifecycleLayer(windowsUrl, "windows")
+	if err != nil {
+		return nil, err
+	}
+
+	windowsDiffID, err := windowsLayer.DiffID()
+	if err != nil {
+		return nil, err
+	}
+
+	image, err = imagehelpers.SetStringLabel(image, "windows", windowsDiffID.String())
 	if err != nil {
 		return nil, err
 	}
 
-	image, err = mutate.AppendLayers(image, layer)
+	image, err = mutate.AppendLayers(image, linuxLayer, windowsLayer)
 	if err != nil {
 		return nil, err
 	}
@@ -96,9 +122,9 @@ func lifecycleImage(url string, lifecycleMetadata cnb.LifecycleMetadata) (v1.Ima
 	})
 }
 
-func lifecycleLayer(url string) (v1.Layer, error) {
+func lifecycleLayer(url, os string) (v1.Layer, error) {
 	b := &bytes.Buffer{}
-	tw := tar.NewWriter(b)
+	tw := newLayerWriter(b, os)
 
 	var regex = regexp.MustCompile(`^[^/]+/([^/]+)$`)
 
@@ -197,3 +223,16 @@ type ReadCloserWrapper struct {
 func (r *ReadCloserWrapper) Close() error {
 	return r.closer()
 }
+
+func newLayerWriter(fileWriter io.Writer, os string) layerWriter {
+	if os == "windows" {
+		return layer.NewWindowsWriter(fileWriter)
+	}
+	return tar.NewWriter(fileWriter)
+}
+
+type layerWriter interface {
+	WriteHeader(hdr *tar.Header) error
+	Write(b []byte) (int, error)
+	Close() error
+}

pkg/cnb/builder_builder.go

@@ -3,10 +3,12 @@ package cnb
 import (
 	"archive/tar"
 	"bytes"
+	"io"
 	"sort"
 	"time"
 
 	"github.com/BurntSushi/toml"
+	"github.com/buildpacks/imgutil/layer"
 	v1 "github.com/google/go-containerregistry/pkg/v1"
 	"github.com/google/go-containerregistry/pkg/v1/mutate"
 	"github.com/google/go-containerregistry/pkg/v1/tarball"
@@ -41,6 +43,7 @@ type builderBlder struct {
 	kpackVersion      string
 	runImage          string
 	mixins            []string
+	os                string
 }
 
 func newBuilderBldr(lifecycleImage v1.Image, kpackVersion string) (*builderBlder, error) {
@@ -58,13 +61,20 @@ func newBuilderBldr(lifecycleImage v1.Image, kpackVersion string) (*builderBlder
 	}, nil
 }
 
-func (bb *builderBlder) AddStack(baseImage v1.Image, clusterStack *v1alpha1.ClusterStack) {
+func (bb *builderBlder) AddStack(baseImage v1.Image, clusterStack *v1alpha1.ClusterStack) error {
+	file, err := baseImage.ConfigFile()
+	if err != nil {
+		return err
+	}
+
+	bb.os = file.OS
 	bb.baseImage = baseImage
 	bb.stackId = clusterStack.Status.Id
 	bb.runImage = clusterStack.Status.RunImage.Image
 	bb.mixins = clusterStack.Status.Mixins
 	bb.cnbUserId = clusterStack.Status.UserID
 	bb.cnbGroupId = clusterStack.Status.GroupID
+	return nil
 }
 
 func (bb *builderBlder) AddGroup(buildpacks ...RemoteBuildpackRef) {
@@ -176,16 +186,17 @@ func (bb *builderBlder) buildpacks() []DescriptiveBuildpackInfo {
 }
 
 func (bb *builderBlder) lifecycleLayer() (v1.Layer, error) {
-	layers, err := bb.lifecycleImage.Layers()
+	diffId, err := imagehelpers.GetStringLabel(bb.lifecycleImage, bb.os)
 	if err != nil {
-		return nil, err
+		return nil, errors.Wrapf(err, "could not find lifecycle for os: %s", bb.os)
 	}
 
-	if len(layers) != 1 {
-		return nil, errors.New("invalid lifecycle image")
+	hash, err := v1.NewHash(diffId)
+	if err != nil {
+		return nil, err
 	}
 
-	return layers[0], nil
+	return bb.lifecycleImage.LayerByDiffID(hash)
 }
 
 func (bb *builderBlder) stackLayer() (v1.Layer, error) {
@@ -207,7 +218,7 @@ func (bb *builderBlder) stackLayer() (v1.Layer, error) {
 	if err != nil {
 		return nil, err
 	}
-	return singeFileLayer(stackTomlPath, stackBuf.Bytes())
+	return bb.singeFileLayer(stackTomlPath, stackBuf.Bytes())
 }
 
 func (bb *builderBlder) orderLayer() (v1.Layer, error) {
@@ -246,12 +257,12 @@ func (bb *builderBlder) orderLayer() (v1.Layer, error) {
 	if err != nil {
 		return nil, err
 	}
-	return singeFileLayer(orderTomlPath, orderBuf.Bytes())
+	return bb.singeFileLayer(orderTomlPath, orderBuf.Bytes())
 }
 
-func singeFileLayer(file string, contents []byte) (v1.Layer, error) {
+func (bb *builderBlder) singeFileLayer(file string, contents []byte) (v1.Layer, error) {
 	b := &bytes.Buffer{}
-	w := tar.NewWriter(b)
+	w := bb.layerWriter(b)
 	if err := w.WriteHeader(&tar.Header{
 		Name:    file,
 		Size:    int64(len(contents)),
@@ -283,7 +294,7 @@ func (bb *builderBlder) defaultDirsLayer() (v1.Layer, error) {
 	}
 
 	b := &bytes.Buffer{}
-	tw := tar.NewWriter(b)
+	tw := bb.layerWriter(b)
 
 	for _, header := range dirs {
 		if err := tw.WriteHeader(header); err != nil {
@@ -318,6 +329,20 @@ func (bb *builderBlder) rootOwnedDir(path string) *tar.Header {
 	}
 }
 
+func (bb *builderBlder) layerWriter(fileWriter io.Writer) layerWriter {
+	if bb.os == "windows" {
+		return layer.NewWindowsWriter(fileWriter)
+	}
+	return tar.NewWriter(fileWriter)
+
+}
+
+type layerWriter interface {
+	WriteHeader(hdr *tar.Header) error
+	Write(b []byte) (int, error)
+	Close() error
+}
+
 func deterministicSortBySize(layers map[DescriptiveBuildpackInfo]buildpackLayer) []DescriptiveBuildpackInfo {
 	keys := make([]DescriptiveBuildpackInfo, 0, len(layers))
 	sizes := make(map[DescriptiveBuildpackInfo]int64, len(layers))

pkg/cnb/create_builder.go

@@ -38,7 +38,10 @@ func (r *RemoteBuilderCreator) CreateBuilder(keychain authn.Keychain, buildpackR
 		return v1alpha1.BuilderRecord{}, err
 	}
 
-	builderBldr.AddStack(buildImage, clusterStack)
+	err = builderBldr.AddStack(buildImage, clusterStack)
+	if err != nil {
+		return v1alpha1.BuilderRecord{}, err
+	}
 
 	for _, group := range spec.Order {
 		buildpacks := make([]RemoteBuildpackRef, 0, len(group.Group))