feat: enable STDIN apply and destroy using RG inventory (#2709)

This commit enables actuation from STDIN using inventory information
that is stored in a ResourceGroup file.

This feature is currently behind a feature gate and will be exposed to
users as a CLI flag in a future commit/PR.

Author: rquitales

internal/cmdapply/cmdapply.go

@@ -108,6 +108,7 @@ type Runner struct {
 	pruneTimeout                 time.Duration
 	inventoryPolicyString        string
 	dryRun                       bool
+	rgFile                       string
 	printStatusEvents            bool
 
 	inventoryPolicy inventory.InventoryPolicy
@@ -166,7 +167,7 @@ func (r *Runner) runE(c *cobra.Command, args []string) error {
 		}
 	}
 
-	objs, inv, err := live.Load(r.factory, path, c.InOrStdin())
+	objs, inv, err := live.Load(r.factory, path, r.rgFile, c.InOrStdin())
 	if err != nil {
 		return err
 	}

internal/cmddestroy/cmddestroy.go

@@ -83,6 +83,7 @@ type Runner struct {
 	output                string
 	inventoryPolicyString string
 	dryRun                bool
+	rgFile                string
 	printStatusEvents     bool
 
 	inventoryPolicy inventory.InventoryPolicy
@@ -128,7 +129,7 @@ func (r *Runner) runE(c *cobra.Command, args []string) error {
 		}
 	}
 
-	_, inv, err := live.Load(r.factory, path, c.InOrStdin())
+	_, inv, err := live.Load(r.factory, path, r.rgFile, c.InOrStdin())
 	if err != nil {
 		return err
 	}

internal/cmdmigrate/migratecmd.go

@@ -301,7 +301,7 @@ func (mr *MigrateRunner) migrateObjs(rgInvClient inventory.InventoryClient,
 		}
 	}
 
-	_, inv, err := live.Load(mr.factory, path, reader)
+	_, inv, err := live.Load(mr.factory, path, mr.rgFile, reader)
 	if err != nil {
 		return err
 	}

internal/pkg/pkg.go

@@ -741,23 +741,28 @@ func ReadRGFile(path, filename string) (*rgfilev1alpha1.ResourceGroup, error) {
 	}
 	defer f.Close()
 
-	rg := &rgfilev1alpha1.ResourceGroup{}
-	c, err := io.ReadAll(f)
+	rg, err := DecodeRGFile(f)
 	if err != nil {
 		return nil, &RGError{
 			Path: types.UniquePath(path),
 			Err:  err,
 		}
 	}
+	return rg, nil
+}
+
+// DecodeRGFile converts a string reader into structured a ResourceGroup object.
+func DecodeRGFile(in io.Reader) (*rgfilev1alpha1.ResourceGroup, error) {
+	rg := &rgfilev1alpha1.ResourceGroup{}
+	c, err := io.ReadAll(in)
+	if err != nil {
+		return rg, err
+	}
 
 	d := yaml.NewDecoder(bytes.NewBuffer(c))
 	d.KnownFields(true)
 	if err := d.Decode(rg); err != nil {
-		return nil, &RGError{
-			Path: types.UniquePath(path),
-			Err:  err,
-		}
+		return rg, err
 	}
 	return rg, nil
-
 }

internal/testutil/pkgbuilder/builder.go

@@ -26,6 +26,7 @@ import (
 	"text/template"
 
 	kptfilev1 "github.com/GoogleContainerTools/kpt/pkg/api/kptfile/v1"
+	rgfilev1alpha1 "github.com/GoogleContainerTools/kpt/pkg/api/resourcegroup/v1alpha1"
 	"github.com/stretchr/testify/assert"
 	"sigs.k8s.io/kustomize/kyaml/yaml"
 )
@@ -92,13 +93,21 @@ var (
 type pkg struct {
 	Kptfile *Kptfile
 
+	RGFile *RGFile
+
 	resources []resourceInfoWithMutators
 
 	files map[string]string
 
 	subPkgs []*SubPkg
 }
 
+// WithRGFile configures the current package to have a resourcegroup file.
+func (rp *RootPkg) WithRGFile(rg *RGFile) *RootPkg {
+	rp.pkg.RGFile = rg
+	return rp
+}
+
 // withKptfile configures the current package to have a Kptfile. Only
 // zero or one Kptfiles are accepted.
 func (p *pkg) withKptfile(kf ...*Kptfile) {
@@ -300,6 +309,22 @@ func (sp *SubPkg) WithSubPackages(ps ...*SubPkg) *SubPkg {
 	return sp
 }
 
+// RGFile represents a minimal resourcegroup.
+type RGFile struct {
+	Name, Namespace, ID string
+}
+
+func NewRGFile() *RGFile {
+	return &RGFile{}
+}
+
+func (rg *RGFile) WithInventory(inv Inventory) *RGFile {
+	rg.Name = inv.Name
+	rg.Namespace = inv.Namespace
+	rg.ID = inv.ID
+	return rg
+}
+
 // Kptfile represents the Kptfile of a package.
 type Kptfile struct {
 	Upstream     *Upstream
@@ -476,6 +501,16 @@ func buildPkg(pkgPath string, pkg *pkg, pkgName string, reposInfo ReposInfo) err
 		}
 	}
 
+	if pkg.RGFile != nil {
+		content := buildRGFile(pkg)
+
+		err := ioutil.WriteFile(filepath.Join(pkgPath, rgfilev1alpha1.RGFileName),
+			[]byte(content), 0600)
+		if err != nil {
+			return err
+		}
+	}
+
 	for _, ri := range pkg.resources {
 		m := ri.resourceInfo.manifest
 		r := yaml.MustParse(m)
@@ -510,6 +545,23 @@ func buildPkg(pkgPath string, pkg *pkg, pkgName string, reposInfo ReposInfo) err
 	return nil
 }
 
+// buildRGFile creates a ResourceGroup inventory file.
+func buildRGFile(pkg *pkg) string {
+	tmp := rgfilev1alpha1.ResourceGroup{ResourceMeta: rgfilev1alpha1.DefaultMeta}
+	tmp.ObjectMeta.Name = pkg.RGFile.Name
+	tmp.ObjectMeta.Namespace = pkg.RGFile.Namespace
+	if pkg.RGFile.ID != "" {
+		tmp.ObjectMeta.Labels = map[string]string{rgfilev1alpha1.RGInventoryIDLabel: pkg.RGFile.ID}
+	}
+
+	b, err := yaml.MarshalWithOptions(tmp, &yaml.EncoderOptions{SeqIndent: yaml.WideSequenceStyle})
+	if err != nil {
+		panic(err)
+	}
+
+	return string(b)
+}
+
 // TODO: Consider using the Kptfile struct for this instead of a template.
 var kptfileTemplate = `apiVersion: kpt.dev/v1
 kind: Kptfile

pkg/api/kptfile/v1/types.go

@@ -326,3 +326,10 @@ type Inventory struct {
 	Labels      map[string]string `yaml:"labels,omitempty" json:"labels,omitempty"`
 	Annotations map[string]string `yaml:"annotations,omitempty" json:"annotations,omitempty"`
 }
+
+func (i Inventory) IsValid() bool {
+	// Name and Namespace are required inventory fields, so we check these 2 fields.
+	// InventoryID is an optional field since we only store it locally if the user
+	// specifies one.
+	return i.Name != "" && i.Namespace != ""
+}