Drain pkg/transformers.

api/transform/maptransformer.go

@@ -0,0 +1,63 @@
+// Copyright 2019 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package transform
+
+import (
+	"errors"
+	"fmt"
+	"sigs.k8s.io/kustomize/v3/api/types"
+	"sigs.k8s.io/kustomize/v3/pkg/resmap"
+)
+
+// mapTransformer applies a string->string map to fieldSpecs.
+type mapTransformer struct {
+	m          map[string]string
+	fieldSpecs []types.FieldSpec
+}
+
+var _ resmap.Transformer = &mapTransformer{}
+
+// NewMapTransformer construct a mapTransformer.
+func NewMapTransformer(
+	pc []types.FieldSpec, m map[string]string) (resmap.Transformer, error) {
+	if m == nil {
+		return newNoOpTransformer(), nil
+	}
+	if pc == nil {
+		return nil, errors.New("fieldSpecs is not expected to be nil")
+	}
+	return &mapTransformer{fieldSpecs: pc, m: m}, nil
+}
+
+// Transform apply each <key, value> pair in the mapTransformer to the
+// fields specified in mapTransformer.
+func (o *mapTransformer) Transform(m resmap.ResMap) error {
+	for _, r := range m.Resources() {
+		for _, path := range o.fieldSpecs {
+			if !r.OrgId().IsSelected(&path.Gvk) {
+				continue
+			}
+			err := MutateField(
+				r.Map(), path.PathSlice(),
+				path.CreateIfNotPresent, o.addMap)
+			if err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+func (o *mapTransformer) addMap(in interface{}) (interface{}, error) {
+	m, ok := in.(map[string]interface{})
+	if in == nil {
+		m = map[string]interface{}{}
+	} else if !ok {
+		return nil, fmt.Errorf("%#v is expected to be %T", in, m)
+	}
+	for k, v := range o.m {
+		m[k] = v
+	}
+	return m, nil
+}