Add support for buildpack API v0.9 (#486)

* Add support for buildpack API v0.9 * Move process-specific printing logic to emitter. --------- Co-authored-by: Rob Dimsdale-Zucker <robert.dimsdale@gmail.com>
paketo-buildpacks · May 11, 2023 · 4a226ae · 4a226ae
1 parent a65afbb
commit 4a226ae
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Showing 6 changed files with 332 additions and 23 deletions.
diff --git a/build.go b/build.go
@@ -144,6 +144,7 @@ func Build(f BuildFunc, options ...Option) {
 	apiV05, _ := semver.NewVersion("0.5")
 	apiV06, _ := semver.NewVersion("0.6")
 	apiV08, _ := semver.NewVersion("0.8")
+	apiV09, _ := semver.NewVersion("0.9")
 	apiVersion, err := semver.NewVersion(buildpackInfo.APIVersion)
 	if err != nil {
 		config.exitHandler.Error(err)
@@ -284,13 +285,27 @@ func Build(f BuildFunc, options ...Option) {
 		}
 
 		var launch struct {
-			Processes []Process  `toml:"processes"`
-			Slices    []Slice    `toml:"slices"`
-			Labels    []label    `toml:"labels"`
-			BOM       []BOMEntry `toml:"bom"`
+			Processes       []Process       `toml:"processes,omitempty"`
+			DirectProcesses []DirectProcess `toml:"processes,omitempty"`
+			Slices          []Slice         `toml:"slices"`
+			Labels          []label         `toml:"labels"`
+			BOM             []BOMEntry      `toml:"bom"`
+		}
+
+		if apiVersion.LessThan(apiV09) {
+			if result.Launch.DirectProcesses != nil {
+				config.exitHandler.Error(errors.New("direct processes can only be used with Buildpack API v0.9 or higher"))
+				return
+			}
+			launch.Processes = result.Launch.Processes
+		} else {
+			if result.Launch.Processes != nil {
+				config.exitHandler.Error(errors.New("non direct processes can only be used with Buildpack API v0.8 or lower"))
+				return
+			}
+			launch.DirectProcesses = result.Launch.DirectProcesses
 		}
 
-		launch.Processes = result.Launch.Processes
 		if apiVersion.LessThan(apiV06) {
 			for _, process := range launch.Processes {
 				if process.Default {

diff --git a/build_test.go b/build_test.go
@@ -209,7 +209,7 @@ api = "0.4"
 
 			return packit.BuildResult{
 				Layers: []packit.Layer{
-					packit.Layer{
+					{
 						Path:   layerPath,
 						Name:   "some-layer",
 						Build:  true,
@@ -256,7 +256,7 @@ api = "0.5"
 
 				return packit.BuildResult{
 					Layers: []packit.Layer{
-						packit.Layer{
+						{
 							Path:   layerPath,
 							Name:   "some-layer",
 							Build:  true,
@@ -292,7 +292,7 @@ cache = true
 
 				return packit.BuildResult{
 					Layers: []packit.Layer{
-						packit.Layer{
+						{
 							Path: layerPath,
 							Name: "some-layer",
 							SBOM: packit.SBOMFormats{
@@ -339,7 +339,7 @@ api = "0.6"
 
 					return packit.BuildResult{
 						Layers: []packit.Layer{
-							packit.Layer{
+							{
 								Path: layerPath,
 								Name: "some-layer",
 								SBOM: packit.SBOMFormats{
@@ -1136,6 +1136,140 @@ api = "0.7"
 				Expect(exitHandler.ErrorCall.Receives.Error).To(MatchError(ContainSubstring("processes can only have a specific working directory with Buildpack API v0.8 or higher")))
 			})
 		})
+
+		context("when the api version is less than 0.9", func() {
+			it.Before(func() {
+				Expect(os.WriteFile(filepath.Join(cnbDir, "buildpack.toml"), []byte(`
+api = "0.8"
+[buildpack]
+  id = "some-id"
+  name = "some-name"
+  version = "some-version"
+  clear-env = false
+`), 0600)).To(Succeed())
+			})
+
+			it("persists a launch.toml", func() {
+				packit.Build(func(ctx packit.BuildContext) (packit.BuildResult, error) {
+					return packit.BuildResult{
+						Launch: packit.LaunchMetadata{
+							Processes: []packit.Process{
+								{
+									Type:             "some-type",
+									Command:          "some-command",
+									Args:             []string{"some-arg"},
+									Direct:           false,
+									Default:          true,
+									WorkingDirectory: "some-working-dir",
+								},
+							},
+						},
+					}, nil
+				}, packit.WithArgs([]string{binaryPath, layersDir, platformDir, planPath}), packit.WithExitHandler(exitHandler))
+
+				contents, err := os.ReadFile(filepath.Join(layersDir, "launch.toml"))
+				Expect(err).NotTo(HaveOccurred())
+
+				Expect(string(contents)).To(MatchTOML(`
+					[[processes]]
+						args = ["some-arg"]
+						command = "some-command"
+						direct = false
+						default = true
+						type = "some-type"
+						working-directory = "some-working-dir"
+				`))
+			})
+
+			context("failure cases", func() {
+				it("throws a specific error when new style proccesses are used", func() {
+
+					packit.Build(func(ctx packit.BuildContext) (packit.BuildResult, error) {
+						return packit.BuildResult{
+							Launch: packit.LaunchMetadata{
+								DirectProcesses: []packit.DirectProcess{
+									{
+										Type:             "some-type",
+										Command:          []string{"some-command"},
+										Args:             []string{"some-arg"},
+										Default:          false,
+										WorkingDirectory: workingDir,
+									},
+								},
+							},
+						}, nil
+					}, packit.WithArgs([]string{binaryPath, layersDir, platformDir, planPath}), packit.WithExitHandler(exitHandler))
+
+					Expect(exitHandler.ErrorCall.Receives.Error).To(MatchError("direct processes can only be used with Buildpack API v0.9 or higher"))
+				})
+			})
+		})
+
+		context("when the api version is 0.9", func() {
+			it.Before(func() {
+				Expect(os.WriteFile(filepath.Join(cnbDir, "buildpack.toml"), []byte(`
+api = "0.9"
+[buildpack]
+  id = "some-id"
+  name = "some-name"
+  version = "some-version"
+  clear-env = false
+`), 0600)).To(Succeed())
+			})
+
+			it("persists a launch.toml", func() {
+				packit.Build(func(ctx packit.BuildContext) (packit.BuildResult, error) {
+					return packit.BuildResult{
+						Launch: packit.LaunchMetadata{
+							DirectProcesses: []packit.DirectProcess{
+								{
+									Type:             "some-type",
+									Command:          []string{"some-command"},
+									Args:             []string{"some-arg"},
+									Default:          true,
+									WorkingDirectory: "some-working-dir",
+								},
+							},
+						},
+					}, nil
+				}, packit.WithArgs([]string{binaryPath, layersDir, platformDir, planPath}), packit.WithExitHandler(exitHandler))
+
+				contents, err := os.ReadFile(filepath.Join(layersDir, "launch.toml"))
+				Expect(err).NotTo(HaveOccurred())
+
+				Expect(string(contents)).To(MatchTOML(`
+					[[processes]]
+						args = ["some-arg"]
+						command = ["some-command"]
+						default = true
+						type = "some-type"
+						working-directory = "some-working-dir"
+				`))
+			})
+			context("failure cases", func() {
+				it("throws a specific error when old style proccesses are used", func() {
+
+					packit.Build(func(ctx packit.BuildContext) (packit.BuildResult, error) {
+						return packit.BuildResult{
+							Launch: packit.LaunchMetadata{
+								Processes: []packit.Process{
+									{
+										Type:             "some-type",
+										Command:          "some-command",
+										Args:             []string{"some-arg"},
+										Direct:           false,
+										Default:          false,
+										WorkingDirectory: workingDir,
+									},
+								},
+							},
+						}, nil
+					}, packit.WithArgs([]string{binaryPath, layersDir, platformDir, planPath}), packit.WithExitHandler(exitHandler))
+
+					Expect(exitHandler.ErrorCall.Receives.Error).To(MatchError("non direct processes can only be used with Buildpack API v0.8 or lower"))
+				})
+			})
+		})
 	})
 
 	context("when there are slices in the result", func() {
@@ -1527,7 +1661,7 @@ api = "0.4"
 				packit.Build(func(ctx packit.BuildContext) (packit.BuildResult, error) {
 					return packit.BuildResult{
 						Layers: []packit.Layer{
-							packit.Layer{
+							{
 								Path: filepath.Join(layersDir, "some-layer"),
 								Name: "some-layer",
 							},
@@ -1544,7 +1678,7 @@ api = "0.4"
 				packit.Build(func(ctx packit.BuildContext) (packit.BuildResult, error) {
 					return packit.BuildResult{
 						Layers: []packit.Layer{
-							packit.Layer{
+							{
 								Path: filepath.Join(layersDir, "some-layer"),
 								Name: "some-layer",
 								SBOM: packit.SBOMFormats{

diff --git a/launch_metadata.go b/launch_metadata.go
@@ -8,6 +8,10 @@ type LaunchMetadata struct {
 	// be executed during the launch phase.
 	Processes []Process
 
+	// DirectProcesses is a list of processes that will be returned to the lifecycle to
+	// be executed directly during the launch phase.
+	DirectProcesses []DirectProcess
+
 	// Slices is a list of slices that will be returned to the lifecycle to be
 	// exported as separate layers during the export phase.
 	Slices []Slice
@@ -31,5 +35,5 @@ func (l LaunchMetadata) isEmpty() bool {
 		sbom = l.SBOM.Formats()
 	}
 
-	return len(sbom)+len(l.Processes)+len(l.Slices)+len(l.Labels)+len(l.BOM) == 0
+	return len(sbom)+len(l.Processes)+len(l.DirectProcesses)+len(l.Slices)+len(l.Labels)+len(l.BOM) == 0
 }
diff --git a/process.go b/process.go
@@ -1,7 +1,7 @@
 package packit
 
 // Process represents a process to be run during the launch phase as described
-// in the specification:
+// in the specification lower than v0.9:
 // https://github.com/buildpacks/spec/blob/main/buildpack.md#launch. The
 // fields of the process are describe in the specification of the launch.toml
 // file:
@@ -28,3 +28,29 @@ type Process struct {
 	// absolute path or one relative to the default application directory.
 	WorkingDirectory string `toml:"working-directory,omitempty"`
 }
+
+// DirectProcess represents a process to be run during the launch phase as described
+// in the specification higher or equal than v0.9:
+// https://github.com/buildpacks/spec/blob/main/buildpack.md#launch. The
+// fields of the process are describe in the specification of the launch.toml
+// file:
+// https://github.com/buildpacks/spec/blob/main/buildpack.md#launchtoml-toml.
+type DirectProcess struct {
+	// Type is an identifier to describe the type of process to be executed, eg.
+	// "web".
+	Type string `toml:"type"`
+
+	// Command is the start command to be executed at launch.
+	Command []string `toml:"command"`
+
+	// Args is a list of arguments to be passed to the command at launch.
+	Args []string `toml:"args"`
+
+	// Default indicates if this process should be the default when launched.
+	Default bool `toml:"default,omitempty"`
+
+	// WorkingDirectory indicates if this process should be run in a working
+	// directory other than the application directory. This can either be an
+	// absolute path or one relative to the default application directory.
+	WorkingDirectory string `toml:"working-directory,omitempty"`
+}