feat: Adding targets and path flags when packaging an extension

Signed-off-by: Costas Papastathis <papastathiscr@gmail.com>

internal/commands/extension_package.go

@@ -2,6 +2,7 @@ package commands
 
 import (
 	"context"
+	"os"
 	"path/filepath"
 
 	"github.com/pkg/errors"
@@ -11,6 +12,7 @@ import (
 	"github.com/buildpacks/pack/internal/config"
 	"github.com/buildpacks/pack/internal/style"
 	"github.com/buildpacks/pack/pkg/client"
+	"github.com/buildpacks/pack/pkg/dist"
 	"github.com/buildpacks/pack/pkg/image"
 	"github.com/buildpacks/pack/pkg/logging"
 )
@@ -19,8 +21,10 @@ import (
 type ExtensionPackageFlags struct {
 	PackageTomlPath string
 	Format          string
+	Targets         []string
 	Publish         bool
 	Policy          string
+	Path            string
 }
 
 // ExtensionPackager packages extensions
@@ -32,9 +36,15 @@ type ExtensionPackager interface {
 func ExtensionPackage(logger logging.Logger, cfg config.Config, packager ExtensionPackager, packageConfigReader PackageConfigReader) *cobra.Command {
 	var flags ExtensionPackageFlags
 	cmd := &cobra.Command{
-		Use:   "package <name> --config <config-path>",
-		Short: "Package an extension in OCI format",
-		Args:  cobra.MatchAll(cobra.ExactArgs(1), cobra.OnlyValidArgs),
+		Use:     "package <name> --config <config-path>",
+		Short:   "Package an extension in OCI format",
+		Args:    cobra.MatchAll(cobra.ExactArgs(1), cobra.OnlyValidArgs),
+		Example: "pack extension package /output/file.cnb --path /extracted/from/tgz/folder --format file\n pack extension package registy/image-name --path  /extracted/from/tgz/folder --format image --publish",
+		Long: "extension package allows users to package (an) extension(s) into OCI format, which can then to be hosted in " +
+			"image repositories or persisted on disk as a '.cnb' file." +
+			"Packaged extensions can be used as inputs to `pack build` (using the `--extension` flag), " +
+			"and they can be included in the configs used in `pack builder create` and `pack extension package`. For more " +
+			"on how to package an extension, see: https://buildpacks.io/docs/buildpack-author-guide/package-a-buildpack/.",
 		RunE: logError(logger, func(cmd *cobra.Command, args []string) error {
 			if err := validateExtensionPackageFlags(&flags); err != nil {
 				return err
@@ -51,6 +61,13 @@ func ExtensionPackage(logger logging.Logger, cfg config.Config, packager Extensi
 			}
 
 			exPackageCfg := pubbldpkg.DefaultExtensionConfig()
+			var exPath string
+			if flags.Path != "" {
+				if exPath, err = filepath.Abs(flags.Path); err != nil {
+					return errors.Wrap(err, "resolving extension path")
+				}
+				exPackageCfg.Extension.URI = exPath
+			}
 			relativeBaseDir := ""
 			if flags.PackageTomlPath != "" {
 				exPackageCfg, err = packageConfigReader.Read(flags.PackageTomlPath)
@@ -74,6 +91,28 @@ func ExtensionPackage(logger logging.Logger, cfg config.Config, packager Extensi
 				}
 			}
 
+			targets, err := processExtensionPackageTargets(flags.Path, packageConfigReader, exPackageCfg)
+			if err != nil {
+				return err
+			}
+
+			daemon := !flags.Publish && flags.Format == ""
+			multiArchCfg, err := processMultiArchitectureConfig(logger, flags.Targets, targets, daemon)
+			if err != nil {
+				return err
+			}
+
+			if len(multiArchCfg.Targets()) == 0 {
+				logger.Infof("Pro tip: use --target flag OR [[targets]] in buildpack.toml to specify the desired platform (os/arch/variant); using os %s", style.Symbol(exPackageCfg.Platform.OS))
+			} else {
+				// FIXME: Check if we can copy the config files during layers creation.
+				filesToClean, err := multiArchCfg.CopyConfigFiles(exPath, "extension")
+				if err != nil {
+					return err
+				}
+				defer clean(filesToClean)
+			}
+
 			if err := packager.PackageExtension(cmd.Context(), client.PackageBuildpackOptions{
 				RelativeBaseDir: relativeBaseDir,
 				Name:            name,
@@ -81,6 +120,7 @@ func ExtensionPackage(logger logging.Logger, cfg config.Config, packager Extensi
 				Config:          exPackageCfg,
 				Publish:         flags.Publish,
 				PullPolicy:      pullPolicy,
+				Targets:         multiArchCfg.Targets(),
 			}); err != nil {
 				return err
 			}
@@ -104,6 +144,14 @@ func ExtensionPackage(logger logging.Logger, cfg config.Config, packager Extensi
 	cmd.Flags().StringVarP(&flags.Format, "format", "f", "", `Format to save package as ("image" or "file")`)
 	cmd.Flags().BoolVar(&flags.Publish, "publish", false, `Publish the extension directly to the container registry specified in <name>, instead of the daemon (applies to "--format=image" only).`)
 	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().StringVarP(&flags.Path, "path", "p", "", "Path to the Extension that needs to be packaged")
+	cmd.Flags().StringSliceVarP(&flags.Targets, "target", "t", nil,
+		`Target platforms to build for.
+Targets 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, "package")
 	return cmd
 }
@@ -114,3 +162,20 @@ func validateExtensionPackageFlags(p *ExtensionPackageFlags) error {
 	}
 	return nil
 }
+
+// processExtensionPackageTargets returns the list of targets defined on the extension.toml
+func processExtensionPackageTargets(path string, packageConfigReader PackageConfigReader, bpPackageCfg pubbldpkg.Config) ([]dist.Target, error) {
+	var targets []dist.Target
+
+	// Read targets from buildpack.toml
+	pathToExtensionToml := filepath.Join(path, "extension.toml")
+	if _, err := os.Stat(pathToExtensionToml); err == nil {
+		buildpackCfg, err := packageConfigReader.ReadBuildpackDescriptor(pathToExtensionToml)
+		if err != nil {
+			return nil, err
+		}
+		targets = buildpackCfg.Targets()
+	}
+
+	return targets, nil
+}

internal/commands/extension_package_test.go

@@ -3,6 +3,7 @@ package commands_test
 import (
 	"bytes"
 	"fmt"
+	"path/filepath"
 	"testing"
 
 	"github.com/heroku/color"
@@ -192,6 +193,39 @@ func testExtensionPackageCommand(t *testing.T, when spec.G, it spec.S) {
 				})
 			})
 		})
+
+		when("a path is specified", func() {
+			when("no multi-platform", func() {
+				it("creates a default config with the appropriate path", func() {
+					cmd := packageExtensionCommand(withExtensionPackager(fakeExtensionPackager))
+					cmd.SetArgs([]string{"some-name", "-p", ".."})
+					h.AssertNil(t, cmd.Execute())
+					bpPath, _ := filepath.Abs("..")
+					receivedOptions := fakeExtensionPackager.CreateCalledWithOptions
+					h.AssertEq(t, receivedOptions.Config.Extension.URI, bpPath)
+				})
+			})
+
+			when("multi-platform", func() {
+				var targets []dist.Target
+
+				when("single extension", func() {
+					it.Before(func() {
+						targets = []dist.Target{
+							{OS: "linux", Arch: "amd64"},
+							{OS: "windows", Arch: "amd64"},
+						}
+					})
+
+					it("creates a multi-platform extension package", func() {
+						cmd := packageExtensionCommand(withExtensionPackager(fakeExtensionPackager))
+						cmd.SetArgs([]string{"some-name", "-p", "some-path", "--target", "linux/amd64", "--target", "windows/amd64", "--format", "image", "--publish"})
+						h.AssertNil(t, cmd.Execute())
+						h.AssertEq(t, fakeExtensionPackager.CreateCalledWithOptions.Targets, targets)
+					})
+				})
+			})
+		})
 	})
 
 	when("invalid flags", func() {
@@ -249,6 +283,20 @@ func testExtensionPackageCommand(t *testing.T, when spec.G, it spec.S) {
 				h.AssertError(t, cmd.Execute(), "parsing pull policy")
 			})
 		})
+
+		when("--target cannot be parsed", func() {
+			it("errors with a descriptive message", func() {
+				cmd := packageCommand()
+				cmd.SetArgs([]string{
+					"some-image-name", "--config", "/path/to/some/file",
+					"--target", "something/wrong", "--publish",
+				})
+
+				err := cmd.Execute()
+				h.AssertNotNil(t, err)
+				h.AssertError(t, err, "unknown target: 'something/wrong'")
+			})
+		})
 	})
 }
 
@@ -318,3 +366,10 @@ func withExtensionClientConfig(clientCfg config.Config) packageExtensionCommandO
 		config.clientConfig = clientCfg
 	}
 }
+
+func whereReadExtensionDescriptor(descriptor dist.ExtensionDescriptor, err error) func(*fakes.FakePackageConfigReader) {
+	return func(r *fakes.FakePackageConfigReader) {
+		r.ReadExtensionDescriptorReturn = descriptor
+		r.ReadBuildpackDescriptorReturnError = err
+	}
+}

internal/commands/fakes/fake_package_config_reader.go

@@ -12,6 +12,7 @@ type FakePackageConfigReader struct {
 
 	ReadBuildpackDescriptorCalledWithArg string
 	ReadBuildpackDescriptorReturn        dist.BuildpackDescriptor
+	ReadExtensionDescriptorReturn        dist.ExtensionDescriptor
 	ReadBuildpackDescriptorReturnError   error
 }
 

pkg/client/package_extension.go

@@ -2,6 +2,8 @@ package client
 
 import (
 	"context"
+	"fmt"
+	"path/filepath"
 
 	"github.com/pkg/errors"
 
@@ -17,47 +19,104 @@ func (c *Client) PackageExtension(ctx context.Context, opts PackageBuildpackOpti
 		opts.Format = FormatImage
 	}
 
-	if opts.Config.Platform.OS == "windows" && !c.experimental {
-		return NewExperimentError("Windows extensionpackage support is currently experimental.")
-	}
-
-	err := c.validateOSPlatform(ctx, opts.Config.Platform.OS, opts.Publish, opts.Format)
+	targets, err := c.processPackageBuildpackTargets(ctx, opts)
 	if err != nil {
 		return err
 	}
+	multiArch := len(targets) > 1 && (opts.Publish || opts.Format == FormatFile)
 
-	writerFactory, err := layer.NewWriterFactory(opts.Config.Platform.OS)
+	var digests []string
+	targets = dist.ExpandTargetsDistributions(targets...)
+	for _, target := range targets {
+		digest, err := c.packageExtensionTarget(ctx, opts, target, multiArch)
+		if err != nil {
+			return err
+		}
+		digests = append(digests, digest)
+	}
+
+	if opts.Publish && len(digests) > 1 {
+		// Image Index must be created only when we pushed to registry
+		return c.CreateManifest(ctx, CreateManifestOptions{
+			IndexRepoName: opts.Name,
+			RepoNames:     digests,
+			Publish:       true,
+		})
+	}
+
+	return nil
+}
+
+func (c *Client) packageExtensionTarget(ctx context.Context, opts PackageBuildpackOptions, target dist.Target, multiArch bool) (string, error) {
+	var digest string
+	if target.OS == "windows" && !c.experimental {
+		return "", NewExperimentError("Windows extensionpackage support is currently experimental.")
+	}
+
+	err := c.validateOSPlatform(ctx, target.OS, opts.Publish, opts.Format)
 	if err != nil {
-		return errors.Wrap(err, "creating layer writer factory")
+		return digest, err
+	}
+
+	writerFactory, err := layer.NewWriterFactory(target.OS)
+	if err != nil {
+		return digest, errors.Wrap(err, "creating layer writer factory")
 	}
 
 	packageBuilder := buildpack.NewBuilder(c.imageFactory)
 
 	exURI := opts.Config.Extension.URI
 	if exURI == "" {
-		return errors.New("extension URI must be provided")
+		return digest, errors.New("extension URI must be provided")
+	}
+
+	if ok, platformRootFolder := buildpack.PlatformRootFolder(exURI, target); ok {
+		exURI = platformRootFolder
 	}
 
 	mainBlob, err := c.downloadBuildpackFromURI(ctx, exURI, opts.RelativeBaseDir)
 	if err != nil {
-		return err
+		return digest, err
 	}
 
 	ex, err := buildpack.FromExtensionRootBlob(mainBlob, writerFactory, c.logger)
 	if err != nil {
-		return errors.Wrapf(err, "creating extension from %s", style.Symbol(exURI))
+		return digest, errors.Wrapf(err, "creating extension from %s", style.Symbol(exURI))
 	}
 
 	packageBuilder.SetExtension(ex)
 
-	target := dist.Target{OS: opts.Config.Platform.OS}
 	switch opts.Format {
 	case FormatFile:
-		return packageBuilder.SaveAsFile(opts.Name, target, map[string]string{})
+		name := opts.Name
+		if multiArch {
+			fileExtension := filepath.Ext(name)
+			origFileName := name[:len(name)-len(filepath.Ext(name))]
+			if target.Arch != "" {
+				name = fmt.Sprintf("%s-%s-%s%s", origFileName, target.OS, target.Arch, fileExtension)
+			} else {
+				name = fmt.Sprintf("%s-%s%s", origFileName, target.OS, fileExtension)
+			}
+		}
+		err = packageBuilder.SaveAsFile(name, target, opts.Labels)
+		if err != nil {
+			return digest, err
+		}
 	case FormatImage:
-		_, err = packageBuilder.SaveAsImage(opts.Name, opts.Publish, target, map[string]string{})
-		return errors.Wrapf(err, "saving image")
+		img, err := packageBuilder.SaveAsImage(opts.Name, opts.Publish, target, opts.Labels)
+		if err != nil {
+			return digest, errors.Wrapf(err, "saving image")
+		}
+		if multiArch {
+			// We need to keep the identifier to create the image index
+			id, err := img.Identifier()
+			if err != nil {
+				return digest, errors.Wrapf(err, "determining image manifest digest")
+			}
+			digest = id.String()
+		}
 	default:
-		return errors.Errorf("unknown format: %s", style.Symbol(opts.Format))
+		return digest, errors.Errorf("unknown format: %s", style.Symbol(opts.Format))
 	}
+	return digest, nil
 }