Improve error handling in kyaml libraries

kyaml/kio/byteio_reader.go

@@ -10,6 +10,7 @@ import (
 	"sort"
 	"strings"
 
+	"sigs.k8s.io/kustomize/kyaml/errors"
 	"sigs.k8s.io/kustomize/kyaml/kio/kioutil"
 	"sigs.k8s.io/kustomize/kyaml/yaml"
 )
@@ -53,7 +54,7 @@ func (rw *ByteReadWriter) Read() ([]*yaml.RNode, error) {
 	rw.FunctionConfig = b.FunctionConfig
 	rw.WrappingApiVersion = b.WrappingApiVersion
 	rw.WrappingKind = b.WrappingKind
-	return val, err
+	return val, errors.Wrap(err)
 }
 
 func (rw *ByteReadWriter) Write(nodes []*yaml.RNode) error {
@@ -84,8 +85,16 @@ type ByteReader struct {
 
 	FunctionConfig *yaml.RNode
 
+	// DisableUnwrapping prevents Resources in Lists and ResourceLists from being unwrapped
+	DisableUnwrapping bool
+
+	// WrappingApiVersion is set by Read(), and is the apiVersion of the object that
+	// the read objects were originally wrapped in.
 	WrappingApiVersion string
-	WrappingKind       string
+
+	// WrappingKind is set by Read(), and is the kind of the object that
+	// the read objects were originally wrapped in.
+	WrappingKind string
 }
 
 var _ Reader = &ByteReader{}
@@ -98,7 +107,7 @@ func (r *ByteReader) Read() ([]*yaml.RNode, error) {
 	input := &bytes.Buffer{}
 	_, err := io.Copy(input, r.Reader)
 	if err != nil {
-		return nil, err
+		return nil, errors.Wrap(err)
 	}
 	values := strings.Split(input.String(), "\n---\n")
 
@@ -110,7 +119,7 @@ func (r *ByteReader) Read() ([]*yaml.RNode, error) {
 			continue
 		}
 		if err != nil {
-			return nil, err
+			return nil, errors.Wrap(err)
 		}
 		if yaml.IsMissingOrNull(node) {
 			// empty value
@@ -118,12 +127,18 @@ func (r *ByteReader) Read() ([]*yaml.RNode, error) {
 		}
 
 		// ok if no metadata -- assume not an InputList
-		meta, _ := node.GetMeta()
+		meta, err := node.GetMeta()
+		if err != yaml.ErrMissingMetadata && err != nil {
+			return nil, errors.WrapPrefixf(err, "[%d]", i)
+		}
 
 		// the elements are wrapped in an InputList, unwrap them
 		// don't check apiVersion, we haven't standardized on the domain
-		if (meta.Kind == ResourceListKind || meta.Kind == "List") &&
+		if !r.DisableUnwrapping &&
+			len(values) == 1 && // Only unwrap if there is only 1 value
+			(meta.Kind == ResourceListKind || meta.Kind == "List") &&
 			node.Field("items") != nil {
+
 			r.WrappingKind = meta.Kind
 			r.WrappingApiVersion = meta.ApiVersion
 
@@ -166,7 +181,7 @@ func (r *ByteReader) decode(index int, decoder *yaml.Decoder) (*yaml.RNode, erro
 		return nil, io.EOF
 	}
 	if err != nil {
-		return nil, err
+		return nil, errors.Wrap(err)
 	}
 
 	if isEmptyDocument(node) {
@@ -191,7 +206,7 @@ func (r *ByteReader) decode(index int, decoder *yaml.Decoder) (*yaml.RNode, erro
 	for _, k := range keys {
 		_, err = n.Pipe(yaml.SetAnnotation(k, r.SetAnnotations[k]))
 		if err != nil {
-			return nil, err
+			return nil, errors.Wrap(err)
 		}
 	}
 	return yaml.NewRNode(node), nil

kyaml/kio/byteio_writer.go

@@ -6,6 +6,7 @@ package kio
 import (
 	"io"
 
+	"sigs.k8s.io/kustomize/kyaml/errors"
 	"sigs.k8s.io/kustomize/kyaml/kio/kioutil"
 	"sigs.k8s.io/kustomize/kyaml/yaml"
 )
@@ -46,7 +47,7 @@ var _ Writer = ByteWriter{}
 func (w ByteWriter) Write(nodes []*yaml.RNode) error {
 	if w.Sort {
 		if err := kioutil.SortNodes(nodes); err != nil {
-			return err
+			return errors.Wrap(err)
 		}
 	}
 
@@ -58,13 +59,13 @@ func (w ByteWriter) Write(nodes []*yaml.RNode) error {
 		if !w.KeepReaderAnnotations {
 			_, err := nodes[i].Pipe(yaml.ClearAnnotation(kioutil.IndexAnnotation))
 			if err != nil {
-				return err
+				return errors.Wrap(err)
 			}
 		}
 		for _, a := range w.ClearAnnotations {
 			_, err := nodes[i].Pipe(yaml.ClearAnnotation(a))
 			if err != nil {
-				return err
+				return errors.Wrap(err)
 			}
 		}
 
@@ -72,11 +73,11 @@ func (w ByteWriter) Write(nodes []*yaml.RNode) error {
 		_, err := nodes[i].Pipe(yaml.Lookup("metadata"), yaml.FieldClearer{
 			Name: "annotations", IfEmpty: true})
 		if err != nil {
-			return err
+			return errors.Wrap(err)
 		}
 		_, err = nodes[i].Pipe(yaml.FieldClearer{Name: "metadata", IfEmpty: true})
 		if err != nil {
-			return err
+			return errors.Wrap(err)
 		}
 
 		if w.Style != 0 {
@@ -89,7 +90,7 @@ func (w ByteWriter) Write(nodes []*yaml.RNode) error {
 		for i := range nodes {
 			err := encoder.Encode(nodes[i].Document())
 			if err != nil {
-				return err
+				return errors.Wrap(err)
 			}
 		}
 		return nil
@@ -118,5 +119,5 @@ func (w ByteWriter) Write(nodes []*yaml.RNode) error {
 	for i := range nodes {
 		items.Content = append(items.Content, nodes[i].YNode())
 	}
-	return encoder.Encode(doc)
+	return errors.Wrap(encoder.Encode(doc))
 }

kyaml/kio/kio.go

@@ -6,6 +6,7 @@
 package kio
 
 import (
+	"sigs.k8s.io/kustomize/kyaml/errors"
 	"sigs.k8s.io/kustomize/kyaml/yaml"
 )
 
@@ -85,7 +86,7 @@ func (p Pipeline) Execute() error {
 	for _, i := range p.Inputs {
 		nodes, err := i.Read()
 		if err != nil {
-			return err
+			return errors.Wrap(err)
 		}
 		result = append(result, nodes...)
 	}
@@ -100,14 +101,14 @@ func (p Pipeline) Execute() error {
 		op := p.Filters[i]
 		result, err = op.Filter(result)
 		if len(result) == 0 || err != nil {
-			return err
+			return errors.Wrap(err)
 		}
 	}
 
 	// write to the outputs
 	for _, o := range p.Outputs {
 		if err := o.Write(result); err != nil {
-			return err
+			return errors.Wrap(err)
 		}
 	}
 	return nil
@@ -119,7 +120,7 @@ func FilterAll(filter yaml.Filter) Filter {
 		for i := range nodes {
 			_, err := filter.Filter(nodes[i])
 			if err != nil {
-				return nil, err
+				return nil, errors.Wrap(err)
 			}
 		}
 		return nodes, nil

kyaml/kio/kioutil/kioutil.go

@@ -8,6 +8,7 @@ import (
 	"sort"
 	"strconv"
 
+	"sigs.k8s.io/kustomize/kyaml/errors"
 	"sigs.k8s.io/kustomize/kyaml/yaml"
 )
 
@@ -40,10 +41,10 @@ func ErrorIfMissingAnnotation(nodes []*yaml.RNode, keys ...AnnotationKey) error
 		for _, node := range nodes {
 			val, err := node.Pipe(yaml.GetAnnotation(key))
 			if err != nil {
-				return err
+				return errors.Wrap(err)
 			}
 			if val == nil {
-				return fmt.Errorf("missing package annotation %s", key)
+				return errors.Errorf("missing package annotation %s", key)
 			}
 		}
 	}
@@ -56,7 +57,7 @@ func Map(nodes []*yaml.RNode, fn func(*yaml.RNode) (*yaml.RNode, error)) ([]*yam
 	for i := range nodes {
 		n, err := fn(nodes[i])
 		if err != nil {
-			return nil, err
+			return nil, errors.Wrap(err)
 		}
 		if n != nil {
 			returnNodes = append(returnNodes, n)
@@ -71,11 +72,11 @@ func MapMeta(nodes []*yaml.RNode, fn func(*yaml.RNode, yaml.ResourceMeta) (*yaml
 	for i := range nodes {
 		meta, err := nodes[i].GetMeta()
 		if err != nil {
-			return nil, err
+			return nil, errors.Wrap(err)
 		}
 		n, err := fn(nodes[i], meta)
 		if err != nil {
-			return nil, err
+			return nil, errors.Wrap(err)
 		}
 		if n != nil {
 			returnNodes = append(returnNodes, n)
@@ -141,5 +142,5 @@ func SortNodes(nodes []*yaml.RNode) error {
 		// elements are equal
 		return false
 	})
-	return err
+	return errors.Wrap(err)
 }

kyaml/kio/pkgio_reader.go

@@ -8,6 +8,7 @@ import (
 	"os"
 	"path/filepath"
 
+	"sigs.k8s.io/kustomize/kyaml/errors"
 	"sigs.k8s.io/kustomize/kyaml/kio/kioutil"
 	"sigs.k8s.io/kustomize/kyaml/sets"
 	"sigs.k8s.io/kustomize/kyaml/yaml"
@@ -81,13 +82,13 @@ func (r *LocalPackageReadWriter) Read() ([]*yaml.RNode, error) {
 		SetAnnotations:      r.SetAnnotations,
 	}.Read()
 	if err != nil {
-		return nil, err
+		return nil, errors.Wrap(err)
 	}
 	// keep track of all the files
 	if !r.NoDeleteFiles {
 		r.files, err = r.getFiles(nodes)
 		if err != nil {
-			return nil, err
+			return nil, errors.Wrap(err)
 		}
 	}
 	return nodes, nil
@@ -96,7 +97,7 @@ func (r *LocalPackageReadWriter) Read() ([]*yaml.RNode, error) {
 func (r *LocalPackageReadWriter) Write(nodes []*yaml.RNode) error {
 	newFiles, err := r.getFiles(nodes)
 	if err != nil {
-		return err
+		return errors.Wrap(err)
 	}
 	var clear []string
 	for k := range r.SetAnnotations {
@@ -108,12 +109,12 @@ func (r *LocalPackageReadWriter) Write(nodes []*yaml.RNode) error {
 		KeepReaderAnnotations: r.KeepReaderAnnotations,
 	}.Write(nodes)
 	if err != nil {
-		return err
+		return errors.Wrap(err)
 	}
 	deleteFiles := r.files.Difference(newFiles)
 	for f := range deleteFiles {
 		if err = os.Remove(filepath.Join(r.PackagePath, f)); err != nil {
-			return err
+			return errors.Wrap(err)
 		}
 	}
 	return nil
@@ -124,7 +125,7 @@ func (r *LocalPackageReadWriter) getFiles(nodes []*yaml.RNode) (sets.String, err
 	for _, n := range nodes {
 		path, _, err := kioutil.GetFileAnnotations(n)
 		if err != nil {
-			return nil, err
+			return nil, errors.Wrap(err)
 		}
 		val.Insert(path)
 	}
@@ -182,7 +183,7 @@ func (r LocalPackageReader) Read() ([]*yaml.RNode, error) {
 	err := filepath.Walk(r.PackagePath, func(
 		path string, info os.FileInfo, err error) error {
 		if err != nil {
-			return err
+			return errors.Wrap(err)
 		}
 
 		// is this the user specified path?
@@ -213,13 +214,13 @@ func (r LocalPackageReader) Read() ([]*yaml.RNode, error) {
 		// to another location.
 		path, err = filepath.Rel(pathRelativeTo, path)
 		if err != nil {
-			return err
+			return errors.WrapPrefixf(err, pathRelativeTo)
 		}
 
 		r.initReaderAnnotations(path, info)
 		nodes, err := r.readFile(filepath.Join(pathRelativeTo, path), info)
 		if err != nil {
-			return err
+			return errors.WrapPrefixf(err, filepath.Join(pathRelativeTo, path))
 		}
 		operand = append(operand, nodes...)
 		return nil
@@ -235,6 +236,7 @@ func (r *LocalPackageReader) readFile(path string, info os.FileInfo) ([]*yaml.RN
 	}
 	defer f.Close()
 	rr := &ByteReader{
+		DisableUnwrapping:     true,
 		Reader:                f,
 		OmitReaderAnnotations: r.OmitReaderAnnotations,
 		SetAnnotations:        r.SetAnnotations,
@@ -247,7 +249,7 @@ func (r *LocalPackageReader) shouldSkipFile(info os.FileInfo) (bool, error) {
 	// check if the files are in scope
 	for _, g := range r.MatchFilesGlob {
 		if match, err := filepath.Match(g, info.Name()); err != nil {
-			return false, err
+			return false, errors.Wrap(err)
 		} else if match {
 			return true, nil
 		}
@@ -276,7 +278,7 @@ func (r *LocalPackageReader) shouldSkipDir(path string) error {
 	if os.IsNotExist(err) {
 		return nil
 	} else if err != nil {
-		return err
+		return errors.Wrap(err)
 	}
 	if !r.IncludeSubpackages {
 		return filepath.SkipDir

kyaml/kio/pkgio_writer.go

@@ -9,6 +9,7 @@ import (
 	"path/filepath"
 	"strings"
 
+	"sigs.k8s.io/kustomize/kyaml/errors"
 	"sigs.k8s.io/kustomize/kyaml/kio/kioutil"
 	"sigs.k8s.io/kustomize/kyaml/yaml"
 )
@@ -52,7 +53,7 @@ func (r LocalPackageWriter) Write(nodes []*yaml.RNode) error {
 	}
 	for k := range outputFiles {
 		if err = kioutil.SortNodes(outputFiles[k]); err != nil {
-			return err
+			return errors.Wrap(err)
 		}
 	}
 
@@ -66,7 +67,7 @@ func (r LocalPackageWriter) Write(nodes []*yaml.RNode) error {
 		outputPath := filepath.Join(r.PackagePath, path)
 		if st, err := os.Stat(outputPath); !os.IsNotExist(err) {
 			if err != nil {
-				return err
+				return errors.Wrap(err)
 			}
 			if st.IsDir() {
 				return fmt.Errorf("config.kubernetes.io/path cannot be a directory: %s", path)
@@ -75,7 +76,7 @@ func (r LocalPackageWriter) Write(nodes []*yaml.RNode) error {
 
 		err = os.MkdirAll(filepath.Dir(outputPath), 0700)
 		if err != nil {
-			return err
+			return errors.Wrap(err)
 		}
 	}
 
@@ -84,12 +85,12 @@ func (r LocalPackageWriter) Write(nodes []*yaml.RNode) error {
 		outputPath := filepath.Join(r.PackagePath, path)
 		err = os.MkdirAll(filepath.Dir(filepath.Join(r.PackagePath, path)), 0700)
 		if err != nil {
-			return err
+			return errors.Wrap(err)
 		}
 
 		f, err := os.OpenFile(outputPath, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, os.FileMode(0600))
 		if err != nil {
-			return err
+			return errors.Wrap(err)
 		}
 		if err := func() error {
 			defer f.Close()
@@ -99,11 +100,11 @@ func (r LocalPackageWriter) Write(nodes []*yaml.RNode) error {
 				ClearAnnotations:      r.ClearAnnotations,
 			}
 			if err = w.Write(outputFiles[path]); err != nil {
-				return err
+				return errors.Wrap(err)
 			}
 			return nil
 		}(); err != nil {
-			return err
+			return errors.Wrap(err)
 		}
 	}
 
@@ -115,10 +116,10 @@ func (r LocalPackageWriter) errorIfMissingRequiredAnnotation(nodes []*yaml.RNode
 		for _, s := range requiredResourcePackageAnnotations {
 			key, err := nodes[i].Pipe(yaml.GetAnnotation(s))
 			if err != nil {
-				return err
+				return errors.Wrap(err)
 			}
 			if key == nil || key.YNode() == nil || key.YNode().Value == "" {
-				return fmt.Errorf(
+				return errors.Errorf(
 					"resources must be annotated with %s to be written to files", s)
 			}
 		}
@@ -135,13 +136,13 @@ func (r LocalPackageWriter) indexByFilePath(nodes []*yaml.RNode) (map[string][]*
 		value, err := node.Pipe(yaml.GetAnnotation(kioutil.PathAnnotation))
 		if err != nil {
 			// this should never happen if errorIfMissingRequiredAnnotation was run
-			return nil, err
+			return nil, errors.Wrap(err)
 		}
 		path := value.YNode().Value
 		outputFiles[path] = append(outputFiles[path], node)
 
 		if filepath.IsAbs(path) {
-			return nil, fmt.Errorf("package paths may not be absolute paths")
+			return nil, errors.Errorf("package paths may not be absolute paths")
 		}
 		if strings.Contains(filepath.Clean(path), "..") {
 			return nil, fmt.Errorf("resource must be written under package %s: %s",