Merge pull request #1145 from monopole/invTransformerPlugin

Convert inventory transformer to plugin, reduce k8sdeps.

go.mod

@@ -27,8 +27,7 @@ require (
 	github.com/spf13/cobra v0.0.2
 	github.com/spf13/pflag v1.0.1
 	github.com/stretchr/testify v1.3.0 // indirect
-	golang.org/x/net v0.0.0-20190225153610-fe579d43d832 // indirect
+	golang.org/x/tools v0.0.0-20190531172133-b3315ee88b7d // indirect
-	golang.org/x/sync v0.0.0-20190227155943-e225da77a7e6 // indirect
 	gopkg.in/inf.v0 v0.9.1 // indirect
 	gopkg.in/yaml.v2 v2.2.1
 	k8s.io/api v0.0.0-20180510062335-53d615ae3f44

go.sum

@@ -58,16 +58,23 @@ github.com/spf13/pflag v1.0.1/go.mod h1:DYY7MBk1bdzusC3SYhjObp+wFpr4gzcvqqNjLnIn
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.3.0 h1:TivCn/peBQ7UY8ooIcPgZFpTNSz0Q2U6UrFlUfqbe0Q=
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
+golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/net v0.0.0-20180906233101-161cd47e91fd/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20190225153610-fe579d43d832 h1:2IdId8zoI92l1bUzjAOygcAOkmCe13HY1j0rqPPPzB8=
 golang.org/x/net v0.0.0-20190225153610-fe579d43d832/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
+golang.org/x/net v0.0.0-20190311183353-d8887717615a h1:oWX7TPOiFAMXLq8o0ikBYfCJVlRHBcsciT5bXOrH628=
+golang.org/x/net v0.0.0-20190311183353-d8887717615a/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/sync v0.0.0-20180314180146-1d60e4601c6f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20190227155943-e225da77a7e6 h1:bjcUS9ztw9kFmmIxJInhon/0Is3p+EHBKNgquIzo1OI=
 golang.org/x/sync v0.0.0-20190227155943-e225da77a7e6/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sys v0.0.0-20180909124046-d0be0721c37e h1:o3PsSEY8E4eXWkXrIP9YJALUkVZqzHJT5DOasTyn8Vs=
 golang.org/x/sys v0.0.0-20180909124046-d0be0721c37e/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/text v0.3.0 h1:g61tztE5qeGQ89tm6NTjjM9VPIm088od1l6aSorWRWg=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+golang.org/x/tools v0.0.0-20190531172133-b3315ee88b7d h1:bt+R27hbE7uVf7PY9S6wpNg9Xo2WRe/XQT0uGq9RQQw=
+golang.org/x/tools v0.0.0-20190531172133-b3315ee88b7d/go.mod h1:/rFqwRUd4F7ZHNgwSSTFct+R/Kf4OFW1sUzUTQQTgfc=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/fsnotify.v1 v1.4.7 h1:xOHLXZwVvI9hhs+cLKq5+I5onOuwQLhQwiu63xxlHs4=

k8sdeps/transformer/factory.go

@@ -5,12 +5,9 @@
 package transformer
 
 import (
-	"sigs.k8s.io/kustomize/k8sdeps/transformer/inventory"
 	"sigs.k8s.io/kustomize/k8sdeps/transformer/patch"
-	"sigs.k8s.io/kustomize/pkg/ifc"
 	"sigs.k8s.io/kustomize/pkg/resource"
 	"sigs.k8s.io/kustomize/pkg/transformers"
-	"sigs.k8s.io/kustomize/pkg/types"
 )
 
 // FactoryImpl makes patch transformer and name hash transformer
@@ -27,11 +24,3 @@ func (p *FactoryImpl) MakePatchTransformer(
 	rf *resource.Factory) (transformers.Transformer, error) {
 	return patch.NewTransformer(slice, rf)
 }
-
-func (p *FactoryImpl) MakeInventoryTransformer(
-	arg *types.Inventory,
-	ldr ifc.Loader,
-	namespace string,
-	gp types.GarbagePolicy) transformers.Transformer {
-	return inventory.NewTransformer(arg, ldr, namespace, gp)
-}

k8sdeps/transformer/inventory/transformer.go

@@ -1,113 +0,0 @@
-// Copyright 2019 The Kubernetes Authors.
-// SPDX-License-Identifier: Apache-2.0
-
-package inventory
-
-import (
-	"fmt"
-
-	"sigs.k8s.io/kustomize/k8sdeps/kunstruct"
-	"sigs.k8s.io/kustomize/pkg/gvk"
-	"sigs.k8s.io/kustomize/pkg/hasher"
-	"sigs.k8s.io/kustomize/pkg/ifc"
-	"sigs.k8s.io/kustomize/pkg/inventory"
-	"sigs.k8s.io/kustomize/pkg/resid"
-	"sigs.k8s.io/kustomize/pkg/resmap"
-	"sigs.k8s.io/kustomize/pkg/resource"
-	"sigs.k8s.io/kustomize/pkg/transformers"
-	"sigs.k8s.io/kustomize/pkg/types"
-)
-
-// transformer compute the inventory object used in prune
-type transformer struct {
-	garbagePolicy types.GarbagePolicy
-	ldr           ifc.Loader
-	cmName        string
-	cmNamespace   string
-}
-
-var _ transformers.Transformer = &transformer{}
-
-// NewTransformer makes a new inventory transformer.
-func NewTransformer(
-	p *types.Inventory,
-	ldr ifc.Loader,
-	namespace string,
-	gp types.GarbagePolicy) transformers.Transformer {
-	if p == nil || p.Type != "ConfigMap" || p.ConfigMap.Namespace != namespace {
-		return transformers.NewNoOpTransformer()
-	}
-	return &transformer{
-		garbagePolicy: gp,
-		ldr:           ldr,
-		cmName:        p.ConfigMap.Name,
-		cmNamespace:   p.ConfigMap.Namespace,
-	}
-}
-
-// Transform generates an inventory object based on the input ResMap.
-// this transformer doesn't change existing resources -
-// it just visits resources and accumulates information to make a new ConfigMap.
-// The prune ConfigMap is used to support the pruning command in the client side tool,
-// which is proposed in https://github.com/kubernetes/enhancements/pull/810
-// The inventory data is written to annotation since
-//   1. The key in data field is constrained and couldn't include arbitrary letters
-//   2. The annotation can be put into any kind of objects
-func (tf *transformer) Transform(m resmap.ResMap) error {
-	invty := inventory.NewInventory()
-	var keys []string
-	for _, r := range m {
-		ns, _ := r.GetFieldValue("metadata.namespace")
-		item := resid.NewItemId(r.GetGvk(), ns, r.GetName())
-		var refs []resid.ItemId
-
-		for _, refid := range r.GetRefBy() {
-			ref := m[refid]
-			ns, _ := ref.GetFieldValue("metadata.namespace")
-			refs = append(refs, resid.NewItemId(ref.GetGvk(), ns, ref.GetName()))
-		}
-		invty.Current[item] = refs
-		keys = append(keys, item.String())
-	}
-	h, err := hasher.SortArrayAndComputeHash(keys)
-	if err != nil {
-		return err
-	}
-
-	args := &types.ConfigMapArgs{}
-	args.Name = tf.cmName
-	args.Namespace = tf.cmNamespace
-	opts := &types.GeneratorOptions{
-		Annotations: make(map[string]string),
-	}
-	opts.Annotations[inventory.HashAnnotation] = h
-	err = invty.UpdateAnnotations(opts.Annotations)
-	if err != nil {
-		return err
-	}
-
-	kf := kunstruct.NewKunstructuredFactoryImpl()
-	k, err := kf.MakeConfigMap(tf.ldr, opts, args)
-	if err != nil {
-		return err
-	}
-
-	if tf.garbagePolicy == types.GarbageCollect {
-		for k := range m {
-			delete(m, k)
-		}
-	}
-
-	id := resid.NewResIdWithPrefixNamespace(
-		gvk.Gvk{
-			Version: "v1",
-			Kind:    "ConfigMap",
-		},
-		tf.cmName,
-		"", tf.cmNamespace)
-	if _, ok := m[id]; ok {
-		return fmt.Errorf("id %v is already used, please use a different name in the prune field", id)
-	}
-	m[id] = resource.NewFactory(kf).FromKunstructured(k)
-	return nil
-}

k8sdeps/transformer/inventory/transformer_test.go

@@ -1,161 +0,0 @@
-// Copyright 2019 The Kubernetes Authors.
-// SPDX-License-Identifier: Apache-2.0
-
-package inventory
-
-import (
-	"reflect"
-	"testing"
-
-	"sigs.k8s.io/kustomize/k8sdeps/kunstruct"
-	"sigs.k8s.io/kustomize/pkg/fs"
-	"sigs.k8s.io/kustomize/pkg/gvk"
-	"sigs.k8s.io/kustomize/pkg/loader"
-	"sigs.k8s.io/kustomize/pkg/resid"
-	"sigs.k8s.io/kustomize/pkg/resmap"
-	"sigs.k8s.io/kustomize/pkg/resource"
-	"sigs.k8s.io/kustomize/pkg/types"
-	"sigs.k8s.io/kustomize/pkg/validators"
-)
-
-var secret = gvk.Gvk{Version: "v1", Kind: "Secret"}
-var cmap = gvk.Gvk{Version: "v1", Kind: "ConfigMap"}
-var deploy = gvk.Gvk{Group: "apps", Version: "v1", Kind: "Deployment"}
-
-func makeResMap() resmap.ResMap {
-	rf := resource.NewFactory(
-		kunstruct.NewKunstructuredFactoryImpl())
-	objs := resmap.ResMap{
-		resid.NewResId(cmap, "cm1"): rf.FromMap(
-			map[string]interface{}{
-				"apiVersion": "v1",
-				"kind":       "ConfigMap",
-				"metadata": map[string]interface{}{
-					"name": "cm1",
-				},
-			}),
-		resid.NewResId(secret, "secret1"): rf.FromMap(
-			map[string]interface{}{
-				"apiVersion": "v1",
-				"kind":       "Secret",
-				"metadata": map[string]interface{}{
-					"name": "secret1",
-				},
-			}),
-		resid.NewResId(deploy, "deploy1"): rf.FromMap(
-			map[string]interface{}{
-				"apiVersion": "apps/v1",
-				"kind":       "Deployment",
-				"metadata": map[string]interface{}{
-					"name": "deploy1",
-				},
-				"spec": map[string]interface{}{
-					"template": map[string]interface{}{
-						"spec": map[string]interface{}{
-							"containers": []interface{}{
-								map[string]interface{}{
-									"name":  "nginx",
-									"image": "nginx:1.7.9",
-									"env": []interface{}{
-										map[string]interface{}{
-											"name": "CM_FOO",
-											"valueFrom": map[string]interface{}{
-												"configMapKeyRef": map[string]interface{}{
-													"name": "cm1",
-													"key":  "somekey",
-												},
-											},
-										},
-									},
-									"envFrom": []interface{}{
-										map[string]interface{}{
-											"configMapRef": map[string]interface{}{
-												"name": "cm1",
-												"key":  "somekey",
-											},
-										},
-										map[string]interface{}{
-											"secretRef": map[string]interface{}{
-												"name": "secret1",
-												"key":  "somekey",
-											},
-										},
-									},
-								},
-							},
-						},
-					},
-				},
-			}),
-	}
-	objs[resid.NewResId(cmap, "cm1")].AppendRefBy(resid.NewResId(deploy, "deploy1"))
-	objs[resid.NewResId(secret, "secret1")].AppendRefBy(resid.NewResId(deploy, "deploy1"))
-	return objs
-}
-
-func TestInventoryTransformer(t *testing.T) {
-	rf := resource.NewFactory(
-		kunstruct.NewKunstructuredFactoryImpl())
-	ldr := loader.NewFileLoaderAtCwd(validators.MakeFakeValidator(), fs.MakeFakeFS())
-
-	// hash is derived based on all keys in the Inventory
-	// It is added to annotations as
-	//   kustomize.config.k8s.io/InventoryHash: hash
-	// When seeing the same annotation, prune binary assumes no
-	// clean up is needed
-	hash := "h44788gt7g"
-
-	// inventory is the derived json string for an Inventory object
-	// It is added to annotations as
-	// kustomize.config.k8s.io/Inventory: inventory
-	inventory := "{\"current\":{\"apps_v1_Deployment|~X|deploy1\":null,\"~G_v1_ConfigMap|~X|cm1\":[{\"group\":\"apps\",\"version\":\"v1\",\"kind\":\"Deployment\",\"name\":\"deploy1\"}],\"~G_v1_Secret|~X|secret1\":[{\"group\":\"apps\",\"version\":\"v1\",\"kind\":\"Deployment\",\"name\":\"deploy1\"}]}}" // nolint
-
-	//  This is the root or inventory object which tracks all
-	// the applied resources - this is the thing we expect the transformer to create.
-	pruneMap := rf.FromMap(
-		map[string]interface{}{
-			"apiVersion": "v1",
-			"kind":       "ConfigMap",
-			"metadata": map[string]interface{}{
-				"name":      "pruneCM",
-				"namespace": "default",
-				"annotations": map[string]interface{}{
-					"kustomize.config.k8s.io/Inventory":     inventory,
-					"kustomize.config.k8s.io/InventoryHash": hash,
-				},
-			},
-		})
-	expected := resmap.ResMap{
-		resid.NewResIdWithPrefixNamespace(cmap, "pruneCM", "", "default"): pruneMap,
-	}
-
-	p := &types.Inventory{
-		Type: "ConfigMap",
-		ConfigMap: types.NameArgs{
-			Name:      "pruneCM",
-			Namespace: "default",
-		},
-	}
-	objs := makeResMap()
-
-	// include the original resmap; only return the ConfigMap for pruning
-	tran := NewTransformer(p, ldr, "default", types.GarbageCollect)
-	tran.Transform(objs)
-
-	if !reflect.DeepEqual(objs, expected) {
-		err := expected.ErrorIfNotEqual(objs)
-		t.Fatalf("actual doesn't match expected: %v", err)
-	}
-
-	objs = makeResMap()
-	expected = objs.DeepCopy(rf)
-	expected[resid.NewResIdWithPrefixNamespace(cmap, "pruneCM", "", "default")] = pruneMap
-	// append the ConfigMap for pruning to the original resmap
-	tran = NewTransformer(p, ldr, "default", types.GarbageIgnore)
-	tran.Transform(objs)
-
-	if !reflect.DeepEqual(objs, expected) {
-		err := expected.ErrorIfNotEqual(objs)
-		t.Fatalf("actual doesn't match expected: %v", err)
-	}
-}

pkg/accumulator/resaccumulator.go

@@ -1,18 +1,5 @@
-/*
+// Copyright 2019 The Kubernetes Authors.
-Copyright 2018 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
-
-Licensed under the Apache License, Version 2.0 (the "License");
-you may not use this file except in compliance with the License.
-You may obtain a copy of the License at
-
-    http://www.apache.org/licenses/LICENSE-2.0
-
-Unless required by applicable law or agreed to in writing, software
-distributed under the License is distributed on an "AS IS" BASIS,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.
-*/
 
 package accumulator
 
@@ -29,7 +16,8 @@ import (
 )
 
 // ResAccumulator accumulates resources and the rules
-// used to customize those resources.
+// used to customize those resources.  It's a ResMap
+// plus stuff needed to modify the ResMap.
 type ResAccumulator struct {
 	resMap  resmap.ResMap
 	tConfig *config.TransformerConfig

pkg/ifc/transformer/factory.go

@@ -5,18 +5,13 @@
 package transformer
 
 import (
-	"sigs.k8s.io/kustomize/pkg/ifc"
 	"sigs.k8s.io/kustomize/pkg/resource"
 	"sigs.k8s.io/kustomize/pkg/transformers"
-	"sigs.k8s.io/kustomize/pkg/types"
 )
 
-// Factory makes transformers
+// Factory makes transformers that require k8sdeps.
 type Factory interface {
-	MakePatchTransformer(slice []*resource.Resource, rf *resource.Factory) (transformers.Transformer, error)
+	MakePatchTransformer(
-	MakeInventoryTransformer(
+		slice []*resource.Resource,
-		p *types.Inventory,
+		rf *resource.Factory) (transformers.Transformer, error)
-		ldr ifc.Loader,
-		namespace string,
-		gp types.GarbagePolicy) transformers.Transformer
 }

pkg/target/kusttarget.go

@@ -127,14 +127,11 @@ func (kt *KustTarget) makeCustomizedResMap(
 	if err != nil {
 		return nil, err
 	}
-	// This must be done last, and not as part of
+
+	// The following steps must be done last, not as part of
 	// the recursion implicit in AccumulateTarget.
-	p := builtin.NewHashTransformerPlugin()
+
-	err = kt.configureBuiltinPlugin(p, nil, "hash")
+	err = kt.addHashesToNames(ra)
-	if err != nil {
-		return nil, err
-	}
-	err = ra.Transform(p)
 	if err != nil {
 		return nil, err
 	}
@@ -145,22 +142,60 @@ func (kt *KustTarget) makeCustomizedResMap(
 	if err != nil {
 		return nil, err
 	}
+
 	// With all the back references fixed, it's OK to resolve Vars.
 	err = ra.ResolveVars()
 	if err != nil {
 		return nil, err
 	}
 
-	rm := ra.ResMap()
+	err = kt.computeInventory(ra, garbagePolicy)
-	pt := kt.tFactory.MakeInventoryTransformer(
-		kt.kustomization.Inventory, kt.ldr,
-		kt.kustomization.Namespace,
-		garbagePolicy)
-	err = pt.Transform(rm)
 	if err != nil {
 		return nil, err
 	}
-	return rm, nil
+
+	return ra.ResMap(), nil
+}
+
+func (kt *KustTarget) addHashesToNames(
+	ra *accumulator.ResAccumulator) error {
+	p := builtin.NewHashTransformerPlugin()
+	err := kt.configureBuiltinPlugin(p, nil, "hash")
+	if err != nil {
+		return err
+	}
+	return ra.Transform(p)
+}
+
+func (kt *KustTarget) computeInventory(
+	ra *accumulator.ResAccumulator, garbagePolicy types.GarbagePolicy) error {
+	inv := kt.kustomization.Inventory
+	if inv == nil {
+		return nil
+	}
+	if inv.Type != "ConfigMap" {
+		return fmt.Errorf("don't know how to do that")
+	}
+
+	if inv.ConfigMap.Namespace != kt.kustomization.Namespace {
+		return fmt.Errorf("namespace mismatch")
+	}
+
+	p := builtin.NewInventoryTransformerPlugin()
+	var c struct {
+		Policy    string
+		Name      string
+		Namespace string
+	}
+	c.Name = inv.ConfigMap.Name
+	c.Namespace = inv.ConfigMap.Namespace
+	c.Policy = garbagePolicy.String()
+
+	err := kt.configureBuiltinPlugin(p, c, "inventory")
+	if err != nil {
+		return err
+	}
+	return ra.Transform(p)
 }
 
 func (kt *KustTarget) shouldAddHashSuffixesToGeneratedResources() bool {

pkg/types/garbagepolicy_string.go

@@ -0,0 +1,25 @@
+// Code generated by "stringer -type=GarbagePolicy"; DO NOT EDIT.
+
+package types
+
+import "strconv"
+
+func _() {
+	// An "invalid array index" compiler error signifies that the constant values have changed.
+	// Re-run the stringer command to generate them again.
+	var x [1]struct{}
+	_ = x[GarbageIgnore-1]
+	_ = x[GarbageCollect-2]
+}
+
+const _GarbagePolicy_name = "GarbageIgnoreGarbageCollect"
+
+var _GarbagePolicy_index = [...]uint8{0, 13, 27}
+
+func (i GarbagePolicy) String() string {
+	i -= 1
+	if i < 0 || i >= GarbagePolicy(len(_GarbagePolicy_index)-1) {
+		return "GarbagePolicy(" + strconv.FormatInt(int64(i+1), 10) + ")"
+	}
+	return _GarbagePolicy_name[_GarbagePolicy_index[i]:_GarbagePolicy_index[i+1]]
+}

pkg/types/kustomization.go

@@ -146,11 +146,11 @@ type Kustomization struct {
 	Inventory *Inventory `json:"inventory,omitempty" yaml:"inventory:omitempty"`
 }
 
+//go:generate stringer -type=GarbagePolicy
 type GarbagePolicy int
 
 const (
-	GarbageUnknown GarbagePolicy = iota
+	GarbageIgnore GarbagePolicy = iota + 1
-	GarbageIgnore
 	GarbageCollect
 )
 

plugin/builtin/HashTransformer.go

@@ -3,6 +3,7 @@ package builtin
 
 import (
 	"fmt"
+
 	"sigs.k8s.io/kustomize/pkg/ifc"
 	"sigs.k8s.io/kustomize/pkg/resmap"
 )

plugin/builtin/InventoryTransformer.go

@@ -0,0 +1,136 @@
+// Code generated by pluginator on InventoryTransformer; DO NOT EDIT.
+package builtin
+
+import (
+	"fmt"
+	"strings"
+
+	"sigs.k8s.io/kustomize/pkg/resource"
+
+	"sigs.k8s.io/kustomize/pkg/hasher"
+	"sigs.k8s.io/kustomize/pkg/ifc"
+	"sigs.k8s.io/kustomize/pkg/inventory"
+	"sigs.k8s.io/kustomize/pkg/resid"
+	"sigs.k8s.io/kustomize/pkg/resmap"
+	"sigs.k8s.io/kustomize/pkg/types"
+	"sigs.k8s.io/yaml"
+)
+
+type InventoryTransformerPlugin struct {
+	ldr       ifc.Loader
+	rf        *resmap.Factory
+	Policy    string `json:"policy,omitempty" yaml:"policy,omitempty"`
+	Name      string `json:"name,omitempty" yaml:"name,omitempty"`
+	Namespace string `json:"namespace,omitempty" yaml:"namespace,omitempty"`
+}
+
+func NewInventoryTransformerPlugin() *InventoryTransformerPlugin {
+	return &InventoryTransformerPlugin{}
+}
+
+func (p *InventoryTransformerPlugin) Config(
+	ldr ifc.Loader, rf *resmap.Factory, c []byte) (err error) {
+	p.ldr = ldr
+	p.rf = rf
+	err = yaml.Unmarshal(c, p)
+	if err != nil {
+		return err
+	}
+	if p.Policy == "" {
+		p.Policy = types.GarbageIgnore.String()
+	}
+	if p.Policy != types.GarbageCollect.String() &&
+		p.Policy != types.GarbageIgnore.String() {
+		return fmt.Errorf(
+			"unrecognized garbagePolicy '%s'", p.Policy)
+	}
+	return nil
+}
+
+// Transform generates an inventory object from the input ResMap.
+// This ConfigMap supports the pruning command in
+// the client side tool proposed here:
+// https://github.com/kubernetes/enhancements/pull/810
+//
+// The inventory data is written to the ConfigMap's
+// annotations, rather than to the key-value pairs in
+// the ConfigMap's data field, since
+//   1. Keys in a ConfigMap's data field are too
+//      constrained for this purpose.
+//   2. Using annotations allow any object to be used,
+//      not just a ConfigMap, should some other object
+//      (e.g. some App object) become more desirable
+//      for this purpose.
+func (p *InventoryTransformerPlugin) Transform(m resmap.ResMap) error {
+
+	inv, h, err := makeInventory(m)
+	if err != nil {
+		return err
+	}
+
+	args := types.ConfigMapArgs{}
+	args.Name = p.Name
+	args.Namespace = p.Namespace
+	opts := &types.GeneratorOptions{
+		Annotations: make(map[string]string),
+	}
+	opts.Annotations[inventory.HashAnnotation] = h
+	err = inv.UpdateAnnotations(opts.Annotations)
+	if err != nil {
+		return err
+	}
+
+	cm, err := p.rf.RF().MakeConfigMap(p.ldr, opts, &args)
+	if err != nil {
+		return err
+	}
+
+	if p.Policy == types.GarbageCollect.String() {
+		for byeBye := range m {
+			delete(m, byeBye)
+		}
+	}
+
+	id := cm.Id()
+	if _, ok := m[id]; ok {
+		return fmt.Errorf(
+			"id '%v' already used; use a different name", id)
+	}
+	m[id] = cm
+	return nil
+}
+
+func makeInventory(m resmap.ResMap) (
+	inv *inventory.Inventory, hash string, err error) {
+	inv = inventory.NewInventory()
+	var keys []string
+	for _, r := range m {
+		ns := getNamespace(r)
+		item := resid.NewItemId(r.GetGvk(), ns, r.GetName())
+		if _, ok := inv.Current[item]; ok {
+			return nil, "", fmt.Errorf(
+				"item '%v' already in inventory", item)
+		}
+		inv.Current[item] = computeRefs(r, m)
+		keys = append(keys, item.String())
+	}
+	h, err := hasher.SortArrayAndComputeHash(keys)
+	return inv, h, err
+}
+
+func getNamespace(r *resource.Resource) string {
+	ns, err := r.GetFieldValue("metadata.namespace")
+	if err != nil && !strings.Contains(err.Error(), "no field named") {
+		panic(err)
+	}
+	return ns
+}
+
+func computeRefs(r *resource.Resource, m resmap.ResMap) (refs []resid.ItemId) {
+	for _, refid := range r.GetRefBy() {
+		ref := m[refid]
+		ns := getNamespace(ref)
+		refs = append(refs, resid.NewItemId(ref.GetGvk(), ns, ref.GetName()))
+	}
+	return
+}

plugin/builtin/inventorytransformer/InventoryTransformer.go

@@ -0,0 +1,137 @@
+// Copyright 2019 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+//go:generate go run sigs.k8s.io/kustomize/plugin/pluginator
+package main
+
+import (
+	"fmt"
+	"strings"
+
+	"sigs.k8s.io/kustomize/pkg/resource"
+
+	"sigs.k8s.io/kustomize/pkg/hasher"
+	"sigs.k8s.io/kustomize/pkg/ifc"
+	"sigs.k8s.io/kustomize/pkg/inventory"
+	"sigs.k8s.io/kustomize/pkg/resid"
+	"sigs.k8s.io/kustomize/pkg/resmap"
+	"sigs.k8s.io/kustomize/pkg/types"
+	"sigs.k8s.io/yaml"
+)
+
+type plugin struct {
+	ldr       ifc.Loader
+	rf        *resmap.Factory
+	Policy    string `json:"policy,omitempty" yaml:"policy,omitempty"`
+	Name      string `json:"name,omitempty" yaml:"name,omitempty"`
+	Namespace string `json:"namespace,omitempty" yaml:"namespace,omitempty"`
+}
+
+var KustomizePlugin plugin
+
+func (p *plugin) Config(
+	ldr ifc.Loader, rf *resmap.Factory, c []byte) (err error) {
+	p.ldr = ldr
+	p.rf = rf
+	err = yaml.Unmarshal(c, p)
+	if err != nil {
+		return err
+	}
+	if p.Policy == "" {
+		p.Policy = types.GarbageIgnore.String()
+	}
+	if p.Policy != types.GarbageCollect.String() &&
+		p.Policy != types.GarbageIgnore.String() {
+		return fmt.Errorf(
+			"unrecognized garbagePolicy '%s'", p.Policy)
+	}
+	return nil
+}
+
+// Transform generates an inventory object from the input ResMap.
+// This ConfigMap supports the pruning command in
+// the client side tool proposed here:
+// https://github.com/kubernetes/enhancements/pull/810
+//
+// The inventory data is written to the ConfigMap's
+// annotations, rather than to the key-value pairs in
+// the ConfigMap's data field, since
+//   1. Keys in a ConfigMap's data field are too
+//      constrained for this purpose.
+//   2. Using annotations allow any object to be used,
+//      not just a ConfigMap, should some other object
+//      (e.g. some App object) become more desirable
+//      for this purpose.
+func (p *plugin) Transform(m resmap.ResMap) error {
+
+	inv, h, err := makeInventory(m)
+	if err != nil {
+		return err
+	}
+
+	args := types.ConfigMapArgs{}
+	args.Name = p.Name
+	args.Namespace = p.Namespace
+	opts := &types.GeneratorOptions{
+		Annotations: make(map[string]string),
+	}
+	opts.Annotations[inventory.HashAnnotation] = h
+	err = inv.UpdateAnnotations(opts.Annotations)
+	if err != nil {
+		return err
+	}
+
+	cm, err := p.rf.RF().MakeConfigMap(p.ldr, opts, &args)
+	if err != nil {
+		return err
+	}
+
+	if p.Policy == types.GarbageCollect.String() {
+		for byeBye := range m {
+			delete(m, byeBye)
+		}
+	}
+
+	id := cm.Id()
+	if _, ok := m[id]; ok {
+		return fmt.Errorf(
+			"id '%v' already used; use a different name", id)
+	}
+	m[id] = cm
+	return nil
+}
+
+func makeInventory(m resmap.ResMap) (
+	inv *inventory.Inventory, hash string, err error) {
+	inv = inventory.NewInventory()
+	var keys []string
+	for _, r := range m {
+		ns := getNamespace(r)
+		item := resid.NewItemId(r.GetGvk(), ns, r.GetName())
+		if _, ok := inv.Current[item]; ok {
+			return nil, "", fmt.Errorf(
+				"item '%v' already in inventory", item)
+		}
+		inv.Current[item] = computeRefs(r, m)
+		keys = append(keys, item.String())
+	}
+	h, err := hasher.SortArrayAndComputeHash(keys)
+	return inv, h, err
+}
+
+func getNamespace(r *resource.Resource) string {
+	ns, err := r.GetFieldValue("metadata.namespace")
+	if err != nil && !strings.Contains(err.Error(), "no field named") {
+		panic(err)
+	}
+	return ns
+}
+
+func computeRefs(r *resource.Resource, m resmap.ResMap) (refs []resid.ItemId) {
+	for _, refid := range r.GetRefBy() {
+		ref := m[refid]
+		ns := getNamespace(ref)
+		refs = append(refs, resid.NewItemId(ref.GetGvk(), ns, ref.GetName()))
+	}
+	return
+}

plugin/builtin/inventorytransformer/InventoryTransformer_test.go

@@ -0,0 +1,125 @@
+// Copyright 2019 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package main_test
+
+import (
+	"testing"
+
+	"sigs.k8s.io/kustomize/pkg/kusttest"
+	"sigs.k8s.io/kustomize/plugin"
+)
+
+const (
+	content = `
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: cm1
+---
+apiVersion: v1
+kind: Secret
+metadata:
+  name: secret1
+---
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: deploy1
+spec:
+  template:
+    spec:
+      containers:
+      - env:
+          name: CM_FOO
+          valueFrom:
+            configMapKeyRef:
+              key: someKey
+              name: cm1
+        envFrom:
+          configMapRef:
+            key: someKey
+            name: cm1
+          secretRef:
+            key: someKey
+            name: secret1
+        image: nginx:1.7.9
+        name: nginx
+`
+	inv = `
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  annotations:
+    kustomize.config.k8s.io/Inventory: '{"current":{"apps_v1_Deployment|~X|deploy1":null,"~G_v1_ConfigMap|~X|cm1":null,"~G_v1_Secret|~X|secret1":null}}'
+    kustomize.config.k8s.io/InventoryHash: h44788gt7g
+  name: pruneCM
+  namespace: default
+`
+)
+
+func TestInventoryTransformerCollect(t *testing.T) {
+	tc := plugin.NewEnvForTest(t).Set()
+	defer tc.Reset()
+
+	tc.BuildGoPlugin(
+		"builtin", "", "InventoryTransformer")
+
+	th := kusttest_test.NewKustTestPluginHarness(t, "/app")
+
+	rm := th.LoadAndRunTransformer(`
+apiVersion: builtin
+kind: InventoryTransformer
+metadata:
+  name: notImportantHere
+policy: GarbageCollect
+name: pruneCM
+namespace: default
+`, content)
+
+	th.AssertActualEqualsExpected(rm, inv)
+}
+
+func TestInventoryTransformerIgnore(t *testing.T) {
+	tc := plugin.NewEnvForTest(t).Set()
+	defer tc.Reset()
+
+	tc.BuildGoPlugin(
+		"builtin", "", "InventoryTransformer")
+
+	th := kusttest_test.NewKustTestPluginHarness(t, "/app")
+
+	rm := th.LoadAndRunTransformer(`
+apiVersion: builtin
+kind: InventoryTransformer
+metadata:
+  name: notImportantHere
+policy: GarbageIgnore
+name: pruneCM
+namespace: default
+`, content)
+
+	th.AssertActualEqualsExpected(rm, inv+"---"+content)
+}
+
+func TestInventoryTransformerDefaultPolicy(t *testing.T) {
+	tc := plugin.NewEnvForTest(t).Set()
+	defer tc.Reset()
+
+	tc.BuildGoPlugin(
+		"builtin", "", "InventoryTransformer")
+
+	th := kusttest_test.NewKustTestPluginHarness(t, "/app")
+
+	rm := th.LoadAndRunTransformer(`
+apiVersion: builtin
+kind: InventoryTransformer
+metadata:
+  name: notImportantHere
+name: pruneCM
+namespace: default
+`, content)
+
+	th.AssertActualEqualsExpected(rm, inv+"---"+content)
+}
+