Implementation of the multi-platform support for builders and buildpack packages RFC 0128

acceptance/assertions/output.go

@@ -173,6 +173,12 @@ func (o OutputAssertionManager) IncludesUsagePrompt() {
 	o.assert.Contains(o.output, "Run 'pack --help' for usage.")
 }
 
+func (o OutputAssertionManager) ReportsBuilderCreated(name string) {
+	o.testObject.Helper()
+
+	o.assert.ContainsF(o.output, "Successfully created builder image '%s'", name)
+}
+
 func (o OutputAssertionManager) ReportsSettingDefaultBuilder(name string) {
 	o.testObject.Helper()
 

acceptance/buildpacks/folder_buildpack.go

@@ -47,4 +47,5 @@ var (
 	ExtFolderSimpleLayers      = folderBuildModule{name: "simple-layers-extension"}
 	MetaBpFolder               = folderBuildModule{name: "meta-buildpack"}
 	MetaBpDependency           = folderBuildModule{name: "meta-buildpack-dependency"}
+	MultiPlatformFolderBP      = folderBuildModule{name: "multi-platform-buildpack"}
 )

acceptance/invoke/pack.go

@@ -239,6 +239,7 @@ const (
 	FlattenBuilderCreationV2
 	FixesRunImageMetadata
 	ManifestCommands
+	MultiPlatformBuildersAndBuildPackages
 )
 
 var featureTests = map[Feature]func(i *PackInvoker) bool{
@@ -278,6 +279,9 @@ var featureTests = map[Feature]func(i *PackInvoker) bool{
 	ManifestCommands: func(i *PackInvoker) bool {
 		return i.atLeast("v0.34.0")
 	},
+	MultiPlatformBuildersAndBuildPackages: func(i *PackInvoker) bool {
+		return i.atLeast("v0.34.0")
+	},
 }
 
 func (i *PackInvoker) SupportsFeature(f Feature) bool {

acceptance/testdata/mock_buildpacks/multi-platform-buildpack/buildpack.toml

@@ -0,0 +1,17 @@
+api = "0.10"
+
+[buildpack]
+  id = "simple/layers"
+  version = "simple-layers-version"
+  name = "Simple Layers Buildpack"
+
+[[targets]]
+os = "linux"
+arch = "amd64"
+
+[[targets]]
+os = "windows"
+arch = "amd64"
+
+[[stacks]]
+  id = "*"

acceptance/testdata/mock_buildpacks/multi-platform-buildpack/linux/amd64/bin/build

@@ -0,0 +1,3 @@
+#!/usr/bin/env bash
+
+echo "---> Build: NOOP Buildpack"

acceptance/testdata/mock_buildpacks/multi-platform-buildpack/linux/amd64/bin/detect

@@ -0,0 +1,3 @@
+#!/usr/bin/env bash
+
+## always detect

acceptance/testdata/mock_buildpacks/multi-platform-buildpack/windows/amd64/bin/build.bat

@@ -0,0 +1,3 @@
+@echo off
+
+echo ---- Build: NOOP Buildpack

acceptance/testdata/mock_buildpacks/multi-platform-buildpack/windows/amd64/bin/detect.bat

@@ -0,0 +1,2 @@
+@echo off
+:: always detect

acceptance/testdata/pack_fixtures/builder_multi_platform-no-targets.toml

@@ -0,0 +1,19 @@
+[[buildpacks]]
+id = "simple/layers"
+version = "simple-layers-version"
+uri = "{{ .BuildpackURI }}"
+
+[[order]]
+[[order.group]]
+id = "simple/layers"
+version = "simple-layers-version"
+
+[build]
+image = "{{ .BuildImage }}"
+
+[run]
+[[run.images]]
+image = "{{ .RunImage }}"
+
+
+

acceptance/testdata/pack_fixtures/builder_multi_platform.toml

@@ -0,0 +1,28 @@
+[[buildpacks]]
+id = "simple/layers"
+version = "simple-layers-version"
+uri = "{{ .BuildpackURI }}"
+
+[[order]]
+[[order.group]]
+id = "simple/layers"
+version = "simple-layers-version"
+
+# Targets the buildpack will work with
+[[targets]]
+os = "linux"
+arch = "amd64"
+
+[[targets]]
+os = "windows"
+arch = "amd64"
+
+[build]
+image = "{{ .BuildImage }}"
+
+[run]
+[[run.images]]
+image = "{{ .RunImage }}"
+
+
+

acceptance/testdata/pack_fixtures/package_aggregate.toml

@@ -5,4 +5,4 @@ uri = "{{ .BuildpackURI }}"
 image = "{{ .PackageName }}"
 
 [platform]
-os = "{{ .OS }}"
+os = "{{ .OS }}"

acceptance/testdata/pack_fixtures/package_multi_platform.toml

@@ -0,0 +1,5 @@
+[buildpack]
+uri = "{{ .BuildpackURI }}"
+
+[[dependencies]]
+uri = "{{ .PackageName }}"

builder/config_reader.go

@@ -25,6 +25,7 @@ type Config struct {
 	Lifecycle       LifecycleConfig  `toml:"lifecycle"`
 	Run             RunConfig        `toml:"run"`
 	Build           BuildConfig      `toml:"build"`
+	Targets         []dist.Target    `toml:"targets"`
 }
 
 // ModuleCollection is a list of ModuleConfigs

buildpackage/config_reader.go

@@ -19,7 +19,11 @@ type Config struct {
 	Buildpack    dist.BuildpackURI `toml:"buildpack"`
 	Extension    dist.BuildpackURI `toml:"extension"`
 	Dependencies []dist.ImageOrURI `toml:"dependencies"`
-	Platform     dist.Platform     `toml:"platform"`
+	// deprecated
+	Platform dist.Platform `toml:"platform"`
+
+	// Define targets for composite buildpacks
+	Targets []dist.Target `toml:"targets"`
 }
 
 func DefaultConfig() Config {
@@ -117,6 +121,17 @@ func (r *ConfigReader) Read(path string) (Config, error) {
 	return packageConfig, nil
 }
 
+func (r *ConfigReader) ReadBuildpackDescriptor(path string) (dist.BuildpackDescriptor, error) {
+	buildpackCfg := dist.BuildpackDescriptor{}
+
+	_, err := toml.DecodeFile(path, &buildpackCfg)
+	if err != nil {
+		return dist.BuildpackDescriptor{}, err
+	}
+
+	return buildpackCfg, nil
+}
+
 func validateURI(uri, relativeBaseDir string) error {
 	locatorType, err := buildpack.GetLocatorType(uri, relativeBaseDir, nil)
 	if err != nil {

go.mod

@@ -5,7 +5,7 @@ require (
 	github.com/Masterminds/semver v1.5.0
 	github.com/Microsoft/go-winio v0.6.2
 	github.com/apex/log v1.9.0
-	github.com/buildpacks/imgutil v0.0.0-20240507132533-9f7b96c3d09d
+	github.com/buildpacks/imgutil v0.0.0-20240514200737-4af87862ff7e
 	github.com/buildpacks/lifecycle v0.19.6
 	github.com/docker/cli v26.1.1+incompatible
 	github.com/docker/docker v26.1.1+incompatible

go.sum

@@ -91,8 +91,8 @@ github.com/beorn7/perks v0.0.0-20180321164747-3a771d992973/go.mod h1:Dwedo/Wpr24
 github.com/beorn7/perks v1.0.0/go.mod h1:KWe93zE9D1o94FZ5RNwFwVgaQK1VOXiVxmqh+CedLV8=
 github.com/beorn7/perks v1.0.1 h1:VlbKKnNfV8bJzeqoa4cOKqO6bYr3WgKZxO8Z16+hsOM=
 github.com/beorn7/perks v1.0.1/go.mod h1:G2ZrVWU2WbWT9wwq4/hrbKbnv/1ERSJQ0ibhJ6rlkpw=
-github.com/buildpacks/imgutil v0.0.0-20240507132533-9f7b96c3d09d h1:GVRuY/C8j4pjOddeeZelbKKLMMX+dYR3TlxE4L1hECU=
-github.com/buildpacks/imgutil v0.0.0-20240507132533-9f7b96c3d09d/go.mod h1:n2R6VRuWsAX3cyHCp/u0Z4WJcixny0gYg075J39owrk=
+github.com/buildpacks/imgutil v0.0.0-20240514200737-4af87862ff7e h1:IBH3oJu2okeB8W+bMTCYsRqbDT1+cjt6GuFtE52tAxM=
+github.com/buildpacks/imgutil v0.0.0-20240514200737-4af87862ff7e/go.mod h1:n2R6VRuWsAX3cyHCp/u0Z4WJcixny0gYg075J39owrk=
 github.com/buildpacks/lifecycle v0.19.6 h1:/bmfMs35aSkxyzYDF+iHl9VnYmUBBbHBmnvo8XNEINk=
 github.com/buildpacks/lifecycle v0.19.6/go.mod h1:sWrBJzf/7dWrcHrWiV/P2+3jS8G8Ki5tczq8jO3XVRQ=
 github.com/bwesterb/go-ristretto v1.2.3/go.mod h1:fUIoIZaG73pV5biE2Blr2xEzDoMj7NFEuV9ekS419A0=

internal/builder/lifecycle.go

@@ -120,3 +120,8 @@ func (l *lifecycle) binaries() []string {
 	}
 	return binaries
 }
+
+// SupportedLinuxArchitecture returns true for each binary architecture available at https://github.com/buildpacks/lifecycle/releases/
+func SupportedLinuxArchitecture(arch string) bool {
+	return arch == "arm64" || arch == "ppc64le" || arch == "s390x"
+}

internal/commands/builder_create.go

@@ -23,6 +23,7 @@ type BuilderCreateFlags struct {
 	Registry        string
 	Policy          string
 	Flatten         []string
+	Targets         []string
 	Label           map[string]string
 }
 
@@ -87,6 +88,15 @@ Creating a custom builder allows you to control what buildpacks are used and wha
 				return err
 			}
 
+			multiArchCfg, err := processMultiArchitectureConfig(logger, flags.Targets, builderConfig.Targets, !flags.Publish)
+			if err != nil {
+				return err
+			}
+
+			if len(multiArchCfg.Targets()) == 0 {
+				logger.Infof("Pro tip: use --targets flag OR [[targets]] in builder.toml to specify the desired platform")
+			}
+
 			imageName := args[0]
 			if err := pack.CreateBuilder(cmd.Context(), client.CreateBuilderOptions{
 				RelativeBaseDir: relativeBaseDir,
@@ -98,6 +108,7 @@ Creating a custom builder allows you to control what buildpacks are used and wha
 				PullPolicy:      pullPolicy,
 				Flatten:         toFlatten,
 				Labels:          flags.Label,
+				Targets:         multiArchCfg.Targets(),
 			}); err != nil {
 				return err
 			}
@@ -116,6 +127,12 @@ Creating a custom builder allows you to control what buildpacks are used and wha
 	cmd.Flags().StringVar(&flags.Policy, "pull-policy", "", "Pull policy to use. Accepted values are always, never, and if-not-present. The default is always")
 	cmd.Flags().StringArrayVar(&flags.Flatten, "flatten", nil, "List of buildpacks to flatten together into a single layer (format: '<buildpack-id>@<buildpack-version>,<buildpack-id>@<buildpack-version>'")
 	cmd.Flags().StringToStringVarP(&flags.Label, "label", "l", nil, "Labels to add to the builder image, in the form of '<name>=<value>'")
+	cmd.Flags().StringSliceVarP(&flags.Targets, "target", "t", nil,
+		`Target platforms to build for.\nTargets should be in the format '[os][/arch][/variant]:[distroname@osversion@anotherversion];[distroname@osversion]'.
+- To specify two different architectures:  '--target "linux/amd64" --target "linux/arm64"'
+- To specify the distribution version: '--target "linux/arm/v6:ubuntu@14.04"'
+- To specify multiple distribution versions: '--target "linux/arm/v6:ubuntu@14.04"  --target "linux/arm/v6:ubuntu@16.04"'
+	`)
 
 	AddHelpFlag(cmd, "create")
 	return cmd