Push suffix/prefix code to plugin.

plugin/builtin/prefixsuffixtransformer/PrefixSuffixTransformer.go

@@ -0,0 +1,101 @@
+// Copyright 2019 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+//go:generate go run sigs.k8s.io/kustomize/plugin/pluginator
+package main
+
+import (
+	"errors"
+	"fmt"
+
+	"sigs.k8s.io/kustomize/pkg/gvk"
+	"sigs.k8s.io/kustomize/pkg/ifc"
+	"sigs.k8s.io/kustomize/pkg/resmap"
+	"sigs.k8s.io/kustomize/pkg/transformers"
+	"sigs.k8s.io/kustomize/pkg/transformers/config"
+	"sigs.k8s.io/yaml"
+)
+
+// Add the given prefix and suffix to the field.
+type plugin struct {
+	Prefix     string             `json:"prefix,omitempty" yaml:"prefix,omitempty"`
+	Suffix     string             `json:"suffix,omitempty" yaml:"suffix,omitempty"`
+	FieldSpecs []config.FieldSpec `json:"fieldSpecs,omitempty" yaml:"fieldSpecs,omitempty"`
+}
+
+var KustomizePlugin plugin
+
+// Not placed in a file yet due to lack of demand.
+var prefixSuffixFieldSpecsToSkip = []config.FieldSpec{
+	{
+		Gvk: gvk.Gvk{Kind: "CustomResourceDefinition"},
+	},
+}
+
+func (p *plugin) Config(
+	ldr ifc.Loader, rf *resmap.Factory, c []byte) (err error) {
+	p.Prefix = ""
+	p.Suffix = ""
+	p.FieldSpecs = nil
+	err = yaml.Unmarshal(c, p)
+	if err != nil {
+		return
+	}
+	if p.FieldSpecs == nil {
+		return errors.New("fieldSpecs is not expected to be nil")
+	}
+	return
+}
+
+func (p *plugin) Transform(m resmap.ResMap) error {
+	if len(p.Prefix) == 0 && len(p.Suffix) == 0 {
+		return nil
+	}
+
+	// Fill map "mf" with entries subject to name modification, and
+	// delete these entries from "m", so that for now m retains only
+	// the entries whose names will not be modified.
+	mf := resmap.New()
+	for id, r := range m.AsMap() {
+		found := false
+		for _, path := range prefixSuffixFieldSpecsToSkip {
+			if id.Gvk().IsSelected(&path.Gvk) {
+				found = true
+				break
+			}
+		}
+		if !found {
+			mf.AppendWithId(id, r)
+			m.Remove(id)
+		}
+	}
+
+	for id, r := range mf.AsMap() {
+		objMap := r.Map()
+		for _, path := range p.FieldSpecs {
+			if !id.Gvk().IsSelected(&path.Gvk) {
+				continue
+			}
+			err := transformers.MutateField(
+				objMap,
+				path.PathSlice(),
+				path.CreateIfNotPresent,
+				p.addPrefixSuffix)
+			if err != nil {
+				return err
+			}
+			newId := id.CopyWithNewPrefixSuffix(p.Prefix, p.Suffix)
+			m.AppendWithId(newId, r)
+		}
+	}
+	return nil
+}
+
+func (p *plugin) addPrefixSuffix(
+	in interface{}) (interface{}, error) {
+	s, ok := in.(string)
+	if !ok {
+		return nil, fmt.Errorf("%#v is expected to be %T", in, s)
+	}
+	return fmt.Sprintf("%s%s%s", p.Prefix, s, p.Suffix), nil
+}