Populate package-path metadata into package context

We construct a path based on the hierarchy of parent packages.  This
is useful for packages/package functions that want to construct values
meaningful beyond just their package - for example domain names, GCP
project IDs, bucket names, descriptions etc.

internal/builtins/pkg_context.go

@@ -30,7 +30,9 @@ import (
 
 const (
 	PkgContextFile = "package-context.yaml"
-	pkgContextName = "kptfile.kpt.dev"
+	PkgContextName = "kptfile.kpt.dev"
+
+	ConfigKeyPackagePath = "package-path"
 )
 
 var (
@@ -42,7 +44,17 @@ var (
 // a KRM object that contains package context information that can be
 // used by functions such as `set-namespace` to customize package with
 // minimal configuration.
-type PackageContextGenerator struct{}
+type PackageContextGenerator struct {
+	// PackageConfig contains the package configuration to set.
+	PackageConfig *PackageConfig
+}
+
+// PackageConfig holds package automatic configuration
+type PackageConfig struct {
+	// PackagePath is the path to the package, as determined by the names of the parent packages.
+	// The path to a package is the parent package path joined with the package name.
+	PackagePath string
+}
 
 // Run function reads the function input `resourceList` from a given reader `r`
 // and writes the function output to the provided writer `w`.
@@ -66,14 +78,14 @@ func (pc *PackageContextGenerator) Process(resourceList *framework.ResourceList)
 	// - Generates a package context resource for each kpt package (i.e Kptfile)
 	for _, resource := range resourceList.Items {
 		gvk := resid.GvkFromNode(resource)
-		if gvk.Equals(configMapGVK) && resource.GetName() == pkgContextName {
+		if gvk.Equals(configMapGVK) && resource.GetName() == PkgContextName {
 			// drop existing package context resources
 			continue
 		}
 		updatedResources = append(updatedResources, resource)
 		if gvk.Equals(kptfileGVK) {
 			// it's a Kptfile, generate a corresponding package context
-			pkgContext, err := pkgContextResource(resource)
+			pkgContext, err := pkgContextResource(resource, pc.PackageConfig)
 			if err != nil {
 				resourceList.Results = framework.Results{
 					&framework.Result{
@@ -102,10 +114,10 @@ func (pc *PackageContextGenerator) Process(resourceList *framework.ResourceList)
 
 // pkgContextResource generates package context resource from a given
 // Kptfile. The resource is generated adjacent to the Kptfile of the package.
-func pkgContextResource(kf *yaml.RNode) (*yaml.RNode, error) {
+func pkgContextResource(kptfile *yaml.RNode, packageConfig *PackageConfig) (*yaml.RNode, error) {
 	cm := yaml.MustParse(AbstractPkgContext())
 
-	kptfilePath, _, err := kioutil.GetFileAnnotations(kf)
+	kptfilePath, _, err := kioutil.GetFileAnnotations(kptfile)
 	if err != nil {
 		return nil, err
 	}
@@ -118,9 +130,16 @@ func pkgContextResource(kf *yaml.RNode) (*yaml.RNode, error) {
 			return nil, err
 		}
 	}
-	cm.SetDataMap(map[string]string{
-		"name": kf.GetName(),
-	})
+	data := map[string]string{
+		"name": kptfile.GetName(),
+	}
+	if packageConfig != nil {
+		if packageConfig.PackagePath != "" {
+			data[ConfigKeyPackagePath] = packageConfig.PackagePath
+		}
+	}
+
+	cm.SetDataMap(data)
 	return cm, nil
 }
 
@@ -136,5 +155,5 @@ metadata:
     config.kubernetes.io/local-config: "true"
 data:
   name: example
-`, pkgContextName)
+`, PkgContextName)
 }

porch/pkg/engine/builtin.go

@@ -33,17 +33,13 @@ type builtinEvalMutation struct {
 	runner   fn.FunctionRunner
 }
 
-func newBuiltinFunctionMutation(function string) (mutation, error) {
-	var runner fn.FunctionRunner
-	switch function {
-	case fnruntime.FuncGenPkgContext:
-		runner = &builtins.PackageContextGenerator{}
-	default:
-		return nil, fmt.Errorf("unrecognized built-in function %q", function)
+func newPackageContextGeneratorMutation(packageConfig *builtins.PackageConfig) (mutation, error) {
+	runner := &builtins.PackageContextGenerator{
+		PackageConfig: packageConfig,
 	}
 
 	return &builtinEvalMutation{
-		function: function,
+		function: fnruntime.FuncGenPkgContext,
 		runner:   runner,
 	}, nil
 }

porch/pkg/engine/builtin_test.go

@@ -20,22 +20,14 @@ import (
 	"path/filepath"
 	"testing"
 
-	"github.com/GoogleContainerTools/kpt/internal/fnruntime"
+	"github.com/GoogleContainerTools/kpt/internal/builtins"
 	"github.com/google/go-cmp/cmp"
 )
 
 const (
 	updateGoldenFiles = "UPDATE_GOLDEN_FILES"
 )
 
-func TestUnknownBuiltinFunctionMutation(t *testing.T) {
-	const doesNotExist = "function-does-not-exist"
-	m, err := newBuiltinFunctionMutation(doesNotExist)
-	if err == nil || m != nil {
-		t.Errorf("creating builtin function runner for an unknown function %q unexpectedly succeeded", doesNotExist)
-	}
-}
-
 func TestPackageContext(t *testing.T) {
 	testdata, err := filepath.Abs(filepath.Join(".", "testdata", "context"))
 	if err != nil {
@@ -44,7 +36,10 @@ func TestPackageContext(t *testing.T) {
 
 	input := readPackage(t, filepath.Join(testdata, "input"))
 
-	m, err := newBuiltinFunctionMutation(fnruntime.FuncGenPkgContext)
+	packageConfig := &builtins.PackageConfig{
+		PackagePath: "parent1/parent1.2/parent1.2.3/me",
+	}
+	m, err := newPackageContextGeneratorMutation(packageConfig)
 	if err != nil {
 		t.Fatalf("Failed to get builtin function mutation: %v", err)
 	}

porch/pkg/engine/clone.go

@@ -21,7 +21,7 @@ import (
 	"os"
 	"strings"
 
-	"github.com/GoogleContainerTools/kpt/internal/fnruntime"
+	"github.com/GoogleContainerTools/kpt/internal/builtins"
 	v1 "github.com/GoogleContainerTools/kpt/pkg/api/kptfile/v1"
 	api "github.com/GoogleContainerTools/kpt/porch/api/porch/v1alpha1"
 	configapi "github.com/GoogleContainerTools/kpt/porch/api/porchconfig/v1alpha1"
@@ -44,6 +44,9 @@ type clonePackageMutation struct {
 	repoOpener         RepositoryOpener
 	credentialResolver repository.CredentialResolver
 	referenceResolver  ReferenceResolver
+
+	// packageConfig contains the package configuration.
+	packageConfig *builtins.PackageConfig
 }
 
 func (m *clonePackageMutation) Apply(ctx context.Context, resources repository.PackageResources) (repository.PackageResources, *api.Task, error) {
@@ -77,13 +80,13 @@ func (m *clonePackageMutation) Apply(ctx context.Context, resources repository.P
 	if m.isDeployment {
 		// TODO(droot): executing this as mutation is not really needed, but can be
 		// refactored once we finalize the task/mutation/commit model.
-		genPkgContextMutation, err := newBuiltinFunctionMutation(fnruntime.FuncGenPkgContext)
+		genPkgContextMutation, err := newPackageContextGeneratorMutation(m.packageConfig)
 		if err != nil {
 			return repository.PackageResources{}, nil, err
 		}
 		cloned, _, err = genPkgContextMutation.Apply(ctx, cloned)
 		if err != nil {
-			return repository.PackageResources{}, nil, fmt.Errorf("failed to generate deployment context %w", err)
+			return repository.PackageResources{}, nil, fmt.Errorf("failed to generate deployment context: %w", err)
 		}
 	}