kyaml: initial support for yaml and resource manipulation

kyaml/yaml/kfns.go

@@ -0,0 +1,66 @@
+// Copyright 2019 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package yaml
+
+import "gopkg.in/yaml.v3"
+
+// AnnotationClearer removes an annotation at metadata.annotations.
+// Returns nil if the annotation or field does not exist.
+type AnnotationClearer struct {
+	Kind string `yaml:"kind,omitempty"`
+	Key  string `yaml:"key,omitempty"`
+}
+
+func (c AnnotationClearer) Filter(rn *RNode) (*RNode, error) {
+	return rn.Pipe(
+		PathGetter{Path: []string{"metadata", "annotations"}},
+		FieldClearer{Name: c.Key})
+}
+
+func ClearAnnotation(key string) AnnotationClearer {
+	return AnnotationClearer{Key: key}
+}
+
+// AnnotationSetter sets an annotation at metadata.annotations.
+// Creates metadata.annotations if does not exist.
+type AnnotationSetter struct {
+	Kind  string `yaml:"kind,omitempty"`
+	Key   string `yaml:"key,omitempty"`
+	Value string `yaml:"value,omitempty"`
+}
+
+func (s AnnotationSetter) Filter(rn *RNode) (*RNode, error) {
+	return rn.Pipe(
+		PathGetter{Path: []string{"metadata", "annotations"}, Create: yaml.MappingNode},
+		FieldSetter{Name: s.Key, Value: NewScalarRNode(s.Value)})
+}
+
+func SetAnnotation(key, value string) AnnotationSetter {
+	return AnnotationSetter{Key: key, Value: value}
+}
+
+// AnnotationGetter gets an annotation at metadata.annotations.
+// Returns nil if metadata.annotations does not exist.
+type AnnotationGetter struct {
+	Kind  string `yaml:"kind,omitempty"`
+	Key   string `yaml:"key,omitempty"`
+	Value string `yaml:"value,omitempty"`
+}
+
+// AnnotationGetter returns the annotation value.
+// Returns "", nil if the annotation does not exist.
+func (g AnnotationGetter) Filter(rn *RNode) (*RNode, error) {
+	v, err := rn.Pipe(PathGetter{Path: []string{"metadata", "annotations", g.Key}})
+	if v == nil || err != nil {
+		return v, err
+	}
+	if g.Value == "" || v.value.Value == g.Value {
+		return v, err
+	}
+	return nil, err
+}
+
+func GetAnnotation(key string) AnnotationGetter {
+	return AnnotationGetter{Key: key}
+}