kyaml: initial support for yaml and resource manipulation

kyaml/kio/kioutil/kioutil.go

@@ -0,0 +1,111 @@
+// Copyright 2019 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package kioutil
+
+import (
+	"fmt"
+	"sort"
+	"strconv"
+
+	"sigs.k8s.io/kustomize/kyaml/yaml"
+)
+
+type AnnotationKey = string
+
+const (
+	// IndexAnnotation records the index of a specific resource in a file or input stream.
+	IndexAnnotation AnnotationKey = "kyaml.kustomize.dev/kio/index"
+
+	// PathAnnotation records the path to the file the Resource was read from
+	PathAnnotation AnnotationKey = "kyaml.kustomize.dev/kio/path"
+
+	// PackageAnnotation records the name of the package the Resource was read from
+	PackageAnnotation AnnotationKey = "kyaml.kustomize.dev/kio/package"
+)
+
+func GetFileAnnotations(rn *yaml.RNode) (string, string, error) {
+	meta, err := rn.GetMeta()
+	if err != nil {
+		return "", "", err
+	}
+	path := meta.Annotations[PathAnnotation]
+	index := meta.Annotations[IndexAnnotation]
+	return path, index, nil
+}
+
+// ErrorIfMissingAnnotation validates the provided annotations are present on the given resources
+func ErrorIfMissingAnnotation(nodes []*yaml.RNode, keys ...AnnotationKey) error {
+	for _, key := range keys {
+		for _, node := range nodes {
+			val, err := node.Pipe(yaml.GetAnnotation(key))
+			if err != nil {
+				return err
+			}
+			if val == nil {
+				return fmt.Errorf("missing package annotation %s", key)
+			}
+		}
+	}
+	return nil
+}
+
+// SortNodes sorts nodes in place:
+// - by PathAnnotation annotation
+// - by IndexAnnotation annotation
+func SortNodes(nodes []*yaml.RNode) error {
+	var err error
+	// use stable sort to keep ordering of equal elements
+	sort.SliceStable(nodes, func(i, j int) bool {
+		if err != nil {
+			return false
+		}
+		var iMeta, jMeta yaml.ResourceMeta
+		if iMeta, _ = nodes[i].GetMeta(); err != nil {
+			return false
+		}
+		if jMeta, _ = nodes[j].GetMeta(); err != nil {
+			return false
+		}
+
+		iValue := iMeta.Annotations[PathAnnotation]
+		jValue := jMeta.Annotations[PathAnnotation]
+		if iValue != jValue {
+			return iValue < jValue
+		}
+
+		iValue = iMeta.Annotations[IndexAnnotation]
+		jValue = jMeta.Annotations[IndexAnnotation]
+
+		// put resource config without an index first
+		if iValue == jValue {
+			return false
+		}
+		if iValue == "" {
+			return true
+		}
+		if jValue == "" {
+			return false
+		}
+
+		// sort by index
+		var iIndex, jIndex int
+		iIndex, err = strconv.Atoi(iValue)
+		if err != nil {
+			err = fmt.Errorf("unable to parse kyaml.kustomize.dev/kio/index %s :%v", iValue, err)
+			return false
+		}
+		jIndex, err = strconv.Atoi(jValue)
+		if err != nil {
+			err = fmt.Errorf("unable to parse kyaml.kustomize.dev/kio/index %s :%v", jValue, err)
+			return false
+		}
+		if iIndex != jIndex {
+			return iValue < jValue
+		}
+
+		// elements are equal
+		return false
+	})
+	return err
+}