setters 2.0: support for adding references to setters

kyaml/setters2/add.go

@@ -0,0 +1,74 @@
+// Copyright 2019 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package setters2
+
+import (
+	"strings"
+
+	"github.com/go-openapi/spec"
+	"sigs.k8s.io/kustomize/kyaml/errors"
+	"sigs.k8s.io/kustomize/kyaml/fieldmeta"
+	"sigs.k8s.io/kustomize/kyaml/yaml"
+)
+
+// Add creates or updates setter or substitution references from resource fields.
+// Requires that at least one of FieldValue and FieldName have been set.
+type Add struct {
+	// FieldValue if set will add the OpenAPI reference to fields if they have this value.
+	// Optional.  If unspecified match all field values.
+	FieldValue string
+
+	// FieldName if set will add the OpenAPI reference to fields with this name or path
+	// FieldName may be the full name of the field, full path to the field, or the path suffix.
+	// e.g. all of the following would match spec.template.spec.containers.image --
+	// [image, containers.image, spec.containers.image, template.spec.containers.image,
+	//  spec.template.spec.containers.image]
+	// Optional.  If unspecified match all field names.
+	FieldName string
+
+	// Ref is the OpenAPI reference to set on the matching fields as a comment.
+	Ref string
+}
+
+// Filter implements yaml.Filter
+func (a *Add) Filter(object *yaml.RNode) (*yaml.RNode, error) {
+	if a.FieldName == "" && a.FieldValue == "" {
+		return nil, errors.Errorf("must specify either fieldName or fieldValue")
+	}
+	if a.Ref == "" {
+		return nil, errors.Errorf("must specify ref")
+	}
+	return object, accept(a, object)
+}
+
+// visitScalar implements visitor
+// visitScalar will set the field metadata on each scalar field whose name + value match
+func (a *Add) visitScalar(object *yaml.RNode, p string) error {
+	// check if the field matches
+	if a.FieldName != "" && !strings.HasSuffix(p, a.FieldName) {
+		return nil
+	}
+	if a.FieldValue != "" && a.FieldValue != object.YNode().Value {
+		return nil
+	}
+
+	// read the field metadata
+	fm := fieldmeta.FieldMeta{}
+	if err := fm.Read(object); err != nil {
+		return err
+	}
+
+	// create the ref on the field metadata
+	r, err := spec.NewRef(a.Ref)
+	if err != nil {
+		return err
+	}
+	fm.Schema.Ref = r
+
+	// write the field metadata
+	if err := fm.Write(object); err != nil {
+		return err
+	}
+	return nil
+}