True and false are mysterious.

k8sdeps/transformer/factory.go

@@ -35,7 +35,9 @@ func NewFactoryImpl() *FactoryImpl {
 }
 
 // MakePatchTransformer makes a new patch transformer
-func (p *FactoryImpl) MakePatchTransformer(slice []*resource.Resource, rf *resource.Factory) (transformers.Transformer, error) {
+func (p *FactoryImpl) MakePatchTransformer(
+	slice []*resource.Resource,
+	rf *resource.Factory) (transformers.Transformer, error) {
 	return patch.NewPatchTransformer(slice, rf)
 }
 
@@ -44,6 +46,9 @@ func (p *FactoryImpl) MakeHashTransformer() transformers.Transformer {
 	return hash.NewNameHashTransformer()
 }
 
-func (p *FactoryImpl) MakeInventoryTransformer(arg *types.Inventory, namespace string, append bool) transformers.Transformer {
-	return inventory.NewInventoryTransformer(arg, namespace, append)
+func (p *FactoryImpl) MakeInventoryTransformer(
+	arg *types.Inventory,
+	namespace string,
+	gp types.GarbagePolicy) transformers.Transformer {
+	return inventory.NewInventoryTransformer(arg, namespace, gp)
 }

k8sdeps/transformer/inventory/inventory.go

@@ -18,22 +18,25 @@ import (
 
 // inventoryTransformer compute the inventory object used in prune
 type inventoryTransformer struct {
-	append      bool
-	cmName      string
-	cmNamespace string
+	garbagePolicy types.GarbagePolicy
+	cmName        string
+	cmNamespace   string
 }
 
 var _ transformers.Transformer = &inventoryTransformer{}
 
 // NewInventoryTransformer makes a inventoryTransformer.
-func NewInventoryTransformer(p *types.Inventory, namespace string, append bool) transformers.Transformer {
+func NewInventoryTransformer(
+	p *types.Inventory,
+	namespace string,
+	gp types.GarbagePolicy) transformers.Transformer {
 	if p == nil || p.Type != "ConfigMap" || p.ConfigMap.Namespace != namespace {
 		return transformers.NewNoOpTransformer()
 	}
 	return &inventoryTransformer{
-		append:      append,
-		cmName:      p.ConfigMap.Name,
-		cmNamespace: p.ConfigMap.Namespace,
+		garbagePolicy: gp,
+		cmName:        p.ConfigMap.Name,
+		cmNamespace:   p.ConfigMap.Namespace,
 	}
 }
 
@@ -84,7 +87,7 @@ func (o *inventoryTransformer) Transform(m resmap.ResMap) error {
 		return err
 	}
 
-	if !o.append {
+	if o.garbagePolicy == types.GarbageCollect {
 		for k := range m {
 			delete(m, k)
 		}

k8sdeps/transformer/inventory/inventory_test.go

@@ -148,7 +148,7 @@ func TestInventoryTransformer(t *testing.T) {
 	objs := makeResMap()
 
 	// include the original resmap; only return the ConfigMap for pruning
-	tran := NewInventoryTransformer(p, "default", false)
+	tran := NewInventoryTransformer(p, "default", types.GarbageCollect)
 	tran.Transform(objs)
 
 	if !reflect.DeepEqual(objs, expected) {
@@ -160,7 +160,7 @@ func TestInventoryTransformer(t *testing.T) {
 	expected = objs.DeepCopy(rf)
 	expected[resid.NewResIdWithPrefixNamespace(cmap, "pruneCM", "", "default")] = pruneMap
 	// append the ConfigMap for pruning to the original resmap
-	tran = NewInventoryTransformer(p, "default", true)
+	tran = NewInventoryTransformer(p, "default", types.GarbageIgnore)
 	tran.Transform(objs)
 
 	if !reflect.DeepEqual(objs, expected) {

pkg/ifc/transformer/factory.go

@@ -27,5 +27,8 @@ import (
 type Factory interface {
 	MakePatchTransformer(slice []*resource.Resource, rf *resource.Factory) (transformers.Transformer, error)
 	MakeHashTransformer() transformers.Transformer
-	MakeInventoryTransformer(p *types.Inventory, namespace string, append bool) transformers.Transformer
+	MakeInventoryTransformer(
+		p *types.Inventory,
+		namespace string,
+		gp types.GarbagePolicy) transformers.Transformer
 }

pkg/target/kusttarget.go

@@ -114,36 +114,15 @@ func unmarshal(y []byte, o interface{}) error {
 // MakeCustomizedResMap creates a ResMap per kustomization instructions.
 // The Resources in the returned ResMap are fully customized.
 func (kt *KustTarget) MakeCustomizedResMap() (resmap.ResMap, error) {
-	ra, err := kt.AccumulateTarget()
-	if err != nil {
-		return nil, err
-	}
-	err = ra.Transform(kt.tFactory.MakeHashTransformer())
-	if err != nil {
-		return nil, err
-	}
-	// Given that names have changed (prefixs/suffixes added),
-	// fix all the back references to those names.
-	err = ra.FixBackReferences()
-	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()
-	pt := kt.tFactory.MakeInventoryTransformer(kt.kustomization.Inventory, kt.kustomization.Namespace, true)
-	err = pt.Transform(rm)
-	if err != nil {
-		return nil, err
-	}
-	return rm, nil
+	return kt.makeCustomizedResMap(types.GarbageIgnore)
 }
 
 func (kt *KustTarget) MakePruneConfigMap() (resmap.ResMap, error) {
+	return kt.makeCustomizedResMap(types.GarbageCollect)
+}
+
+func (kt *KustTarget) makeCustomizedResMap(
+	garbagePolicy types.GarbagePolicy) (resmap.ResMap, error) {
 	ra, err := kt.AccumulateTarget()
 	if err != nil {
 		return nil, err
@@ -165,7 +144,10 @@ func (kt *KustTarget) MakePruneConfigMap() (resmap.ResMap, error) {
 	}
 
 	rm := ra.ResMap()
-	pt := kt.tFactory.MakeInventoryTransformer(kt.kustomization.Inventory, kt.kustomization.Namespace, false)
+	pt := kt.tFactory.MakeInventoryTransformer(
+		kt.kustomization.Inventory,
+		kt.kustomization.Namespace,
+		garbagePolicy)
 	err = pt.Transform(rm)
 	if err != nil {
 		return nil, err

pkg/types/kustomization.go

@@ -142,6 +142,14 @@ type Kustomization struct {
 	Inventory *Inventory `json:"inventory,omitempty" yaml:"inventory:omitempty"`
 }
 
+type GarbagePolicy int
+
+const (
+	GarbageUnknown GarbagePolicy = iota
+	GarbageIgnore
+	GarbageCollect
+)
+
 // FixKustomizationPostUnmarshalling fixes things
 // like empty fields that should not be empty, or
 // moving content of deprecated fields to newer