Support Buildpack API 0.10

build.go

@@ -55,8 +55,14 @@ type BuildContext struct {
 	// Platform is the contents of the platform.
 	Platform Platform
 
-	// StackID is the ID of the stack.
+	// Deprecated: StackID is the ID of the stack.
 	StackID string
+
+	// TargetInfo contains info of the target (os, arch, ...).
+	TargetInfo TargetInfo
+
+	// TargetDistro is the target distribution (name, version).
+	TargetDistro TargetDistro
 }
 
 // BuildResult contains the results of detection.
@@ -87,7 +93,7 @@ const (
 	MinSupportedBPVersion = "0.8"
 
 	// MaxSupportedBPVersion indicates the maximum supported version of the Buildpacks API
-	MaxSupportedBPVersion = "0.9"
+	MaxSupportedBPVersion = "0.10"
 )
 
 // NewBuildResult creates a new BuildResult instance, initializing empty fields.
@@ -231,6 +237,19 @@ func Build(build BuildFunc, config Config) {
 		config.logger.Debugf("Stack: %s", ctx.StackID)
 	}
 
+	if API.GreaterThan(semver.MustParse("0.9")) {
+		ctx.TargetInfo = TargetInfo{}
+		ctx.TargetInfo.OS, _ = os.LookupEnv(EnvTargetOS)
+		ctx.TargetInfo.Arch, _ = os.LookupEnv(EnvTargetArch)
+		ctx.TargetInfo.Variant, _ = os.LookupEnv(EnvTargetArchVariant)
+		config.logger.Debugf("System: %+v", ctx.TargetInfo)
+
+		ctx.TargetDistro = TargetDistro{}
+		ctx.TargetDistro.Name, _ = os.LookupEnv(EnvTargetDistroName)
+		ctx.TargetDistro.Version, _ = os.LookupEnv(EnvTargetDistroVersion)
+		config.logger.Debugf("Distro: %+v", ctx.TargetDistro)
+	}
+
 	result, err := build(ctx)
 	if err != nil {
 		config.exitHandler.Error(err)

build_test.go

@@ -165,6 +165,12 @@ test-key = "test-value"
 		Expect(os.Setenv("CNB_PLATFORM_DIR", platformPath)).To(Succeed())
 		Expect(os.Setenv("CNB_BP_PLAN_PATH", buildpackPlanPath)).To(Succeed())
 
+		Expect(os.Setenv("CNB_TARGET_OS", "linux")).To(Succeed())
+		Expect(os.Setenv("CNB_TARGET_ARCH", "arm")).To(Succeed())
+		Expect(os.Setenv("CNB_TARGET_ARCH_VARIANT", "v6")).To(Succeed())
+		Expect(os.Setenv("CNB_TARGET_DISTRO_NAME", "ubuntu")).To(Succeed())
+		Expect(os.Setenv("CNB_TARGET_DISTRO_VERSION", "24.04")).To(Succeed())
+
 		workingDir, err = os.Getwd()
 		Expect(err).NotTo(HaveOccurred())
 		Expect(os.Chdir(applicationPath)).To(Succeed())
@@ -178,6 +184,12 @@ test-key = "test-value"
 		Expect(os.Unsetenv("CNB_BP_PLAN_PATH")).To(Succeed())
 		Expect(os.Unsetenv("CNB_LAYERS_DIR")).To(Succeed())
 
+		Expect(os.Unsetenv("CNB_TARGET_OS"))
+		Expect(os.Unsetenv("CNB_TARGET_ARCH"))
+		Expect(os.Unsetenv("CNB_TARGET_ARCH_VARIANT"))
+		Expect(os.Unsetenv("CNB_TARGET_DISTRO_NAME"))
+		Expect(os.Unsetenv("CNB_TARGET_DISTRO_VERSION"))
+
 		Expect(os.RemoveAll(applicationPath)).To(Succeed())
 		Expect(os.RemoveAll(buildpackPath)).To(Succeed())
 		Expect(os.RemoveAll(buildpackPlanPath)).To(Succeed())
@@ -320,6 +332,69 @@ version = "1.1.1"
 		})
 	})
 
+	context("has a build environment specifying target metadata", func() {
+		var ctx libcnb.BuildContext
+
+		it.Before(func() {
+			Expect(os.WriteFile(filepath.Join(buildpackPath, "buildpack.toml"),
+				[]byte(`
+						api = "0.10"
+
+						[buildpack]
+						id = "test-id"
+						name = "test-name"
+						version = "1.1.1"
+
+						[[targets]]
+						os = "linux"
+						arch = "amd64"
+
+						[[targets.distros]]
+						name = "ubuntu"
+						version = "18.04"
+
+						[[targets.distros]]
+						name = "debian"
+
+						[[targets]]
+						os = "linux"
+						arch = "arm"
+						variant = "v6"
+					`), 0600),
+			).To(Succeed())
+
+			buildFunc = func(context libcnb.BuildContext) (libcnb.BuildResult, error) {
+				ctx = context
+				return libcnb.NewBuildResult(), nil
+			}
+		})
+
+		it("provides target information", func() {
+			libcnb.Build(buildFunc,
+				libcnb.NewConfig(
+					libcnb.WithArguments([]string{commandPath}),
+					libcnb.WithLogger(log.New(os.Stdout)),
+				),
+			)
+
+			Expect(ctx.Buildpack.Targets).To(HaveLen(2))
+			Expect(ctx.Buildpack.Targets[0].OS).To(Equal("linux"))
+			Expect(ctx.Buildpack.Targets[0].Arch).To(Equal("amd64"))
+			Expect(ctx.Buildpack.Targets[0].Distros).To(HaveLen(2))
+			Expect(ctx.Buildpack.Targets[0].Distros[0].Name).To(Equal("ubuntu"))
+			Expect(ctx.Buildpack.Targets[0].Distros[0].Version).To(Equal("18.04"))
+			Expect(ctx.Buildpack.Targets[0].Distros[1].Name).To(Equal("debian"))
+
+			Expect(ctx.Buildpack.Targets[1].Variant).To(Equal("v6"))
+
+			Expect(ctx.TargetInfo.OS).To(Equal("linux"))
+			Expect(ctx.TargetInfo.Arch).To(Equal("arm"))
+			Expect(ctx.TargetInfo.Variant).To(Equal("v6"))
+			Expect(ctx.TargetDistro.Name).To(Equal("ubuntu"))
+			Expect(ctx.TargetDistro.Version).To(Equal("24.04"))
+		})
+	})
+
 	it("fails if CNB_BUILDPACK_DIR is not set", func() {
 		Expect(os.Unsetenv("CNB_BUILDPACK_DIR")).To(Succeed())
 

buildpack.go

@@ -76,7 +76,7 @@ type BuildpackOrder struct {
 	Groups []BuildpackOrderBuildpack `toml:"group"`
 }
 
-// BuildpackStack is a stack supported by the buildpack.
+// Deprecated: BuildpackStack is a stack supported by the buildpack.
 type BuildpackStack struct {
 	// ID is the id of the stack.
 	ID string `toml:"id"`
@@ -85,6 +85,35 @@ type BuildpackStack struct {
 	Mixins []string `toml:"mixins"`
 }
 
+// TargetDistro is the supported target distro
+type TargetDistro struct {
+	// Name is the name of the supported distro.
+	Name string `toml:"name"`
+
+	// Version is the version of the supported distro.
+	Version string `toml:"version"`
+}
+
+// TargetInfo is the supported target
+type TargetInfo struct {
+	// OS is the supported os.
+	OS string `toml:"os"`
+
+	// Arch is the supported architecture.
+	Arch string `toml:"arch"`
+
+	// Variant is the supported variant of the architecture.
+	Variant string `toml:"variant"`
+}
+
+// Target is a target supported by the buildpack.
+type Target struct {
+	TargetInfo
+
+	// Distros is the collection of distros associated with the target.
+	Distros []TargetDistro `toml:"distros"`
+}
+
 // Buildpack is the contents of the buildpack.toml file.
 type Buildpack struct {
 	// API is the api version expected by the buildpack.
@@ -96,9 +125,12 @@ type Buildpack struct {
 	// Path is the path to the buildpack.
 	Path string `toml:"-"`
 
-	// Stacks is the collection of stacks supported by the buildpack.
+	// Deprecated: Stacks is the collection of stacks supported by the buildpack.
 	Stacks []BuildpackStack `toml:"stacks"`
 
+	// Targets is the collection of targets supported by the buildpack.
+	Targets []Target `toml:"targets"`
+
 	// Metadata is arbitrary metadata attached to the buildpack.
 	Metadata map[string]interface{} `toml:"metadata"`
 }

extension.go

@@ -51,6 +51,9 @@ type Extension struct {
 	// Path is the path to the extension.
 	Path string `toml:"-"`
 
+	// Targets is the collection of targets supported by the buildpack.
+	Targets []Target `toml:"targets"`
+
 	// Metadata is arbitrary metadata attached to the extension.
 	Metadata map[string]interface{} `toml:"metadata"`
 }

generate.go

@@ -50,18 +50,44 @@ type GenerateContext struct {
 	// Platform is the contents of the platform.
 	Platform Platform
 
-	// StackID is the ID of the stack.
+	// TargetInfo contains info of the target (os, arch, ...).
+	TargetInfo TargetInfo
+
+	// TargetDistro is the target distribution (name, version).
+	TargetDistro TargetDistro
+
+	// Deprecated: StackID is the ID of the stack.
 	StackID string
 }
 
 // GenerateResult contains the results of detection.
 type GenerateResult struct {
 	// Unmet contains buildpack plan entries that were not satisfied by the buildpack and therefore should be
 	// passed to subsequent providers.
-	Unmet []UnmetPlanEntry
+	Unmet           []UnmetPlanEntry
+	RunDockerfile   []byte
+	BuildDockerfile []byte
+	Config          *ExtendConfig
+}
+
+// DockerfileArg is a Dockerfile argument
+type DockerfileArg struct {
+	Name  string `toml:"name"`
+	Value string `toml:"value"`
 }
 
-// NewBuildResult creates a new BuildResult instance, initializing empty fields.
+// BuildConfig contains additional arguments passed to the generated Dockerfiles
+type BuildConfig struct {
+	Args []DockerfileArg `toml:"args"`
+}
+
+// ExtendConfig contains additional configuration for the Dockerfiles
+type ExtendConfig struct {
+	Build BuildConfig `toml:"build"`
+	Run   BuildConfig `toml:"run"`
+}
+
+// NewGenerateResult creates a new BuildResult instance, initializing empty fields.
 func NewGenerateResult() GenerateResult {
 	return GenerateResult{}
 }
@@ -73,7 +99,7 @@ func (b GenerateResult) String() string {
 	)
 }
 
-// BuildFunc takes a context and returns a result, performing extension generate behaviors.
+// GenerateFunc takes a context and returns a result, performing extension generate behaviors.
 type GenerateFunc func(context GenerateContext) (GenerateResult, error)
 
 // Generate is called by the main function of a extension, for generate phase
@@ -184,10 +210,52 @@ func Generate(generate GenerateFunc, config Config) {
 		config.logger.Debugf("Stack: %s", ctx.StackID)
 	}
 
+	if API.GreaterThan(semver.MustParse("0.9")) {
+		ctx.TargetInfo = TargetInfo{}
+		ctx.TargetInfo.OS, _ = os.LookupEnv(EnvTargetOS)
+		ctx.TargetInfo.Arch, _ = os.LookupEnv(EnvTargetArch)
+		ctx.TargetInfo.Variant, _ = os.LookupEnv(EnvTargetArchVariant)
+		config.logger.Debugf("System: %+v", ctx.TargetInfo)
+
+		ctx.TargetDistro = TargetDistro{}
+		ctx.TargetDistro.Name, _ = os.LookupEnv(EnvTargetDistroName)
+		ctx.TargetDistro.Version, _ = os.LookupEnv(EnvTargetDistroVersion)
+		config.logger.Debugf("Distro: %+v", ctx.TargetDistro)
+	}
+
 	result, err := generate(ctx)
 	if err != nil {
 		config.exitHandler.Error(err)
 		return
 	}
 	config.logger.Debugf("Result: %+v", result)
+
+	if len(result.RunDockerfile) > 0 {
+		// #nosec
+		if err := os.WriteFile(filepath.Join(ctx.OutputDirectory, "run.Dockerfile"), result.RunDockerfile, 0644); err != nil {
+			config.exitHandler.Error(err)
+			return
+		}
+	}
+
+	if len(result.BuildDockerfile) > 0 {
+		// #nosec
+		if err := os.WriteFile(filepath.Join(ctx.OutputDirectory, "build.Dockerfile"), result.BuildDockerfile, 0644); err != nil {
+			config.exitHandler.Error(err)
+			return
+		}
+	}
+
+	if result.Config != nil {
+		configFile, err := os.Create(filepath.Join(ctx.OutputDirectory, "extend-config.toml"))
+		if err != nil {
+			config.exitHandler.Error(err)
+			return
+		}
+
+		if err := toml.NewEncoder(configFile).Encode(result.Config); err != nil {
+			config.exitHandler.Error(err)
+			return
+		}
+	}
 }