setters 2.0

kyaml/setters2/walk.go

@@ -0,0 +1,45 @@
+// Copyright 2019 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package setters2
+
+import (
+	"sigs.k8s.io/kustomize/kyaml/yaml"
+)
+
+// visitor is implemented by structs which need to walk the configuration.
+// visitor is provided to accept to walk configuration
+type visitor interface {
+	// visitScalar is called for each scalar field value on a resource
+	// node is the scalar field value
+	// path is the path to the field; path elements are separated by '.'
+	visitScalar(node *yaml.RNode, path string) error
+}
+
+// accept invokes the appropriate function on v for each field in object
+func accept(v visitor, object *yaml.RNode) error {
+	return acceptImpl(v, object, "")
+}
+
+// acceptImpl implements accept using recursion
+func acceptImpl(v visitor, object *yaml.RNode, p string) error {
+	switch object.YNode().Kind {
+	case yaml.DocumentNode:
+		// Traverse the child of the document
+		return accept(v, yaml.NewRNode(object.YNode()))
+	case yaml.MappingNode:
+		return object.VisitFields(func(node *yaml.MapNode) error {
+			// Traverse each field value
+			return acceptImpl(v, node.Value, p+"."+node.Key.YNode().Value)
+		})
+	case yaml.SequenceNode:
+		return object.VisitElements(func(node *yaml.RNode) error {
+			// Traverse each list element
+			return acceptImpl(v, node, p)
+		})
+	case yaml.ScalarNode:
+		// Visit the scalar field
+		return v.visitScalar(object, p)
+	}
+	return nil
+}