Validate builder Lifecycle Platform API Version

Makefile

@@ -13,7 +13,7 @@ all: clean verify test build
 build:
 	@echo "> Building..."
 	mkdir -p ./out
-	$(GOENV) $(GOCMD) build -mod=vendor -ldflags "-X 'main.Version=${PACK_VERSION}'" -o ./out/$(PACK_BIN) -a ./cmd/pack
+	$(GOENV) $(GOCMD) build -mod=vendor -ldflags "-X 'github.com/buildpack/pack/cmd.Version=${PACK_VERSION}'" -o ./out/$(PACK_BIN) -a ./cmd/pack
 
 package:
 	tar czf ./out/$(ARCHIVE_NAME).tgz -C out/ pack

build.go

@@ -15,8 +15,10 @@ import (
 	"github.com/google/go-containerregistry/pkg/name"
 	"github.com/pkg/errors"
 
+	"github.com/buildpack/pack/api"
 	"github.com/buildpack/pack/build"
 	"github.com/buildpack/pack/builder"
+	"github.com/buildpack/pack/cmd"
 	"github.com/buildpack/pack/internal/archive"
 	"github.com/buildpack/pack/internal/paths"
 	"github.com/buildpack/pack/style"
@@ -69,14 +71,14 @@ func (c *Client) Build(ctx context.Context, opts BuildOptions) error {
 		return errors.Wrapf(err, "failed to fetch builder image '%s'", builderRef.Name())
 	}
 
-	builderImage, err := c.processBuilderImage(rawBuilderImage)
+	bldr, err := c.processBuilderImage(rawBuilderImage)
 	if err != nil {
 		return errors.Wrapf(err, "invalid builder '%s'", opts.Builder)
 	}
 
-	runImage := c.resolveRunImage(opts.RunImage, imageRef.Context().RegistryStr(), builderImage.GetStackInfo(), opts.AdditionalMirrors)
+	runImage := c.resolveRunImage(opts.RunImage, imageRef.Context().RegistryStr(), bldr.GetStackInfo(), opts.AdditionalMirrors)
 
-	if _, err := c.validateRunImage(ctx, runImage, opts.NoPull, opts.Publish, builderImage.StackID); err != nil {
+	if _, err := c.validateRunImage(ctx, runImage, opts.NoPull, opts.Publish, bldr.StackID); err != nil {
 		return errors.Wrapf(err, "invalid run-image '%s'", runImage)
 	}
 
@@ -91,6 +93,30 @@ func (c *Client) Build(ctx context.Context, opts BuildOptions) error {
 	}
 	defer c.docker.ImageRemove(context.Background(), ephemeralBuilder.Name(), types.ImageRemoveOptions{Force: true})
 
+	descriptor := ephemeralBuilder.GetLifecycleDescriptor()
+	lifecycleVersion := descriptor.Info.Version
+	if lifecycleVersion == nil {
+		c.logger.Warnf("lifecycle version unknown, assuming %s", style.Symbol(builder.AssumedLifecycleVersion))
+		lifecycleVersion = builder.VersionMustParse(builder.AssumedLifecycleVersion)
+	} else {
+		c.logger.Debugf("Executing lifecycle version %s", style.Symbol(lifecycleVersion.String()))
+	}
+
+	lcPlatformAPIVersion := api.MustParse(builder.AssumedPlatformAPIVersion)
+	if descriptor.API.PlatformVersion != nil {
+		lcPlatformAPIVersion = descriptor.API.PlatformVersion
+	}
+
+	if !api.MustParse(build.PlatformAPIVersion).SupportsVersion(lcPlatformAPIVersion) {
+		return errors.Errorf(
+			"pack %s (Platform API version %s) is incompatible with builder %s (Platform API version %s)",
+			cmd.Version,
+			build.PlatformAPIVersion,
+			style.Symbol(opts.Builder),
+			lcPlatformAPIVersion,
+		)
+	}
+
 	return c.lifecycle.Execute(ctx, build.LifecycleOptions{
 		AppPath:    appPath,
 		Image:      imageRef,

build/build.go

@@ -16,6 +16,9 @@ import (
 	"github.com/buildpack/pack/style"
 )
 
+// PlatformAPIVersion is the current Platform API Version supported by this version of pack.
+const PlatformAPIVersion = "0.1"
+
 type Lifecycle struct {
 	builder      *builder.Builder
 	logger       logging.Logger
@@ -69,14 +72,6 @@ func (l *Lifecycle) Execute(ctx context.Context, opts LifecycleOptions) error {
 		l.logger.Debugf("Build cache %s cleared", style.Symbol(buildCache.Name()))
 	}
 
-	lifecycleVersion := l.builder.GetLifecycleDescriptor().Info.Version
-	if lifecycleVersion == nil {
-		l.logger.Warnf("lifecycle version unknown, assuming %s", style.Symbol(builder.AssumedLifecycleVersion))
-		lifecycleVersion = builder.VersionMustParse(builder.AssumedLifecycleVersion)
-	} else {
-		l.logger.Debugf("Executing lifecycle version %s", style.Symbol(lifecycleVersion.String()))
-	}
-
 	l.logger.Debug(style.Step("DETECTING"))
 	if err := l.Detect(ctx); err != nil {
 		return err

build_test.go

@@ -25,8 +25,11 @@ import (
 
 	"github.com/buildpack/pack/api"
 	"github.com/buildpack/pack/blob"
+	"github.com/buildpack/pack/build"
 	"github.com/buildpack/pack/builder"
+	"github.com/buildpack/pack/cmd"
 	ifakes "github.com/buildpack/pack/internal/fakes"
+	"github.com/buildpack/pack/style"
 	h "github.com/buildpack/pack/testhelpers"
 )
 
@@ -90,7 +93,7 @@ func testBuild(t *testing.T, when spec.G, it spec.S) {
 					},
 					API: builder.LifecycleAPI{
 						BuildpackVersion: api.MustParse("0.3"),
-						PlatformVersion:  api.MustParse("0.2"),
+						PlatformVersion:  api.MustParse(build.PlatformAPIVersion),
 					},
 				},
 			},
@@ -336,6 +339,11 @@ func testBuild(t *testing.T, when spec.G, it spec.S) {
 									Image: "some/run",
 								},
 							},
+							Lifecycle: builder.LifecycleMetadata{
+								API: builder.LifecycleAPI{
+									PlatformVersion: api.MustParse(build.PlatformAPIVersion),
+								},
+							},
 						})
 
 					fakeImageFetcher.LocalImages[customBuilderImage.Name()] = customBuilderImage
@@ -911,6 +919,80 @@ func testBuild(t *testing.T, when spec.G, it spec.S) {
 				})
 			})
 		})
+
+		when("Lifecycle option", func() {
+			when("Platform API", func() {
+				when("lifecycle platform API is compatible", func() {
+					it("should succeed", func() {
+						err := subject.Build(context.TODO(), BuildOptions{
+							Image:   "some/app",
+							Builder: builderName,
+						})
+
+						h.AssertNil(t, err)
+					})
+				})
+
+				when("lifecycle platform API is not compatible", func() {
+					var incompatibleBuilderImage *fakes.Image
+					it.Before(func() {
+						incompatibleBuilderImage = ifakes.NewFakeBuilderImage(t,
+							"incompatible-"+builderName,
+							defaultBuilderStackID,
+							"1234",
+							"5678",
+							builder.Metadata{
+								Stack: builder.StackMetadata{
+									RunImage: builder.RunImageMetadata{
+										Image: "default/run",
+										Mirrors: []string{
+											"registry1.example.com/run/mirror",
+											"registry2.example.com/run/mirror",
+										},
+									},
+								},
+								Lifecycle: builder.LifecycleMetadata{
+									LifecycleInfo: builder.LifecycleInfo{
+										Version: &builder.Version{
+											Version: *semver.MustParse("0.3.0"),
+										},
+									},
+									API: builder.LifecycleAPI{
+										BuildpackVersion: api.MustParse("0.3"),
+										PlatformVersion:  api.MustParse("0.9"),
+									},
+								},
+							},
+						)
+
+						fakeImageFetcher.LocalImages[incompatibleBuilderImage.Name()] = incompatibleBuilderImage
+					})
+
+					it.After(func() {
+						incompatibleBuilderImage.Cleanup()
+					})
+
+					it("should error", func() {
+						builderName := incompatibleBuilderImage.Name()
+
+						err := subject.Build(context.TODO(), BuildOptions{
+							Image:   "some/app",
+							Builder: builderName,
+						})
+
+						h.AssertError(t,
+							err,
+							fmt.Sprintf(
+								"pack %s (Platform API version %s) is incompatible with builder %s (Platform API version %s)",
+								cmd.Version,
+								build.PlatformAPIVersion,
+								style.Symbol(builderName),
+								"0.9",
+							))
+					})
+				})
+			})
+		})
 	})
 }
 

cmd/cmd.go

@@ -0,0 +1,6 @@
+package cmd
+
+var (
+	// Version is the version of `pack`. It is injected at compile time.
+	Version = "0.0.0"
+)

cmd/pack/main.go

@@ -8,16 +8,14 @@ import (
 	"github.com/spf13/cobra"
 
 	"github.com/buildpack/pack"
+	"github.com/buildpack/pack/cmd"
 	"github.com/buildpack/pack/commands"
 	"github.com/buildpack/pack/config"
 	clilogger "github.com/buildpack/pack/internal/logging"
 	"github.com/buildpack/pack/logging"
 )
 
-var (
-	Version    = "0.0.0"
-	packClient pack.Client
-)
+var packClient pack.Client
 
 func main() {
 	// create logger with defaults
@@ -64,7 +62,7 @@ func main() {
 	rootCmd.AddCommand(commands.SuggestBuilders(logger, &packClient))
 
 	rootCmd.AddCommand(commands.SuggestStacks(logger))
-	rootCmd.AddCommand(commands.Version(logger, Version))
+	rootCmd.AddCommand(commands.Version(logger, cmd.Version))
 
 	rootCmd.AddCommand(commands.CompletionCommand(logger))