Checkpoint

api/go.mod

@@ -12,6 +12,7 @@ require (
 	github.com/yujunz/go-getter v1.4.1-lite
 	golang.org/x/tools v0.0.0-20191010075000-0337d82405ff
 	gopkg.in/yaml.v2 v2.3.0
+	gopkg.in/yaml.v3 v3.0.0-20200121175148-a6ecf24a6d71
 	k8s.io/api v0.17.0
 	k8s.io/apimachinery v0.17.0
 	k8s.io/client-go v0.17.0

api/internal/merge/merginator.go

@@ -0,0 +1,25 @@
+// Copyright 2020 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package merge
+
+import (
+	"sigs.k8s.io/kustomize/api/resmap"
+	"sigs.k8s.io/kustomize/api/resource"
+)
+
+// Merginator implements resmap.Merginator using kyaml libs.
+type Merginator struct {
+}
+
+var _ resmap.Merginator = (*Merginator)(nil)
+
+func NewMerginator(_ *resource.Factory) *Merginator {
+	return &Merginator{}
+}
+
+// Merge implements resmap.Merginator
+func (m Merginator) Merge(
+	resources []*resource.Resource) (resmap.ResMap, error) {
+	panic("TODO(#Merginator): implement Merge")
+}

api/internal/merge/merginator_test.go

@@ -0,0 +1,4 @@
+// Copyright 2020 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package merge_test

api/internal/validate/fieldvalidator.go

@@ -0,0 +1,64 @@
+// Copyright 2020 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package validate
+
+import (
+	"sigs.k8s.io/kustomize/api/ifc"
+)
+
+// FieldValidator implements ifc.Validator to check
+// the values of various KRM string fields,
+// e.g. labels, annotations, names, namespaces.
+type FieldValidator struct {
+}
+
+var _ ifc.Validator = (*FieldValidator)(nil)
+
+func NewFieldValidator() *FieldValidator {
+	return &FieldValidator{}
+}
+
+// TODO(#FieldValidator): implement MakeAnnotationValidator
+func (f FieldValidator) MakeAnnotationValidator() func(map[string]string) error {
+	return func(x map[string]string) error {
+		return nil
+	}
+}
+
+// TODO(#FieldValidator): implement MakeAnnotationNameValidator
+func (f FieldValidator) MakeAnnotationNameValidator() func([]string) error {
+	return func(x []string) error {
+		return nil
+	}
+}
+
+// TODO(#FieldValidator): implement MakeLabelValidator
+func (f FieldValidator) MakeLabelValidator() func(map[string]string) error {
+	return func(x map[string]string) error {
+		return nil
+	}
+}
+
+// TODO(#FieldValidator): implement MakeLabelNameValidator
+func (f FieldValidator) MakeLabelNameValidator() func([]string) error {
+	return func(x []string) error {
+		return nil
+	}
+}
+
+// TODO(#FieldValidator): implement ValidateNamespace
+func (f FieldValidator) ValidateNamespace(s string) []string {
+	var errs []string
+	return errs
+}
+
+// TODO(#FieldValidator): implement ErrIfInvalidKey
+func (f FieldValidator) ErrIfInvalidKey(s string) error {
+	return nil
+}
+
+// TODO(#FieldValidator): implement IsEnvVarName
+func (f FieldValidator) IsEnvVarName(k string) error {
+	return nil
+}

api/internal/validate/fieldvalidator_test.go

@@ -0,0 +1,4 @@
+// Copyright 2020 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package validate_test

api/internal/wrappy/factory.go

@@ -0,0 +1,41 @@
+// Copyright 2020 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package wrappy
+
+import (
+	"sigs.k8s.io/kustomize/api/ifc"
+	"sigs.k8s.io/kustomize/api/types"
+)
+
+// WNodeFactory makes instances of WNode.
+// These instances in turn adapt
+//   sigs.k8s.io/kustomize/kyaml/yaml.RNode
+// to implement ifc.Unstructured.
+// This factory is meant to implement ifc.KunstructuredFactory.
+type WNodeFactory struct {
+}
+
+var _ ifc.KunstructuredFactory = (*WNodeFactory)(nil)
+
+func (k *WNodeFactory) SliceFromBytes(bs []byte) ([]ifc.Kunstructured, error) {
+	panic("TODO(#WNodeFactory): implement SliceFromBytes")
+}
+
+func (k *WNodeFactory) FromMap(m map[string]interface{}) ifc.Kunstructured {
+	panic("TODO(#WNodeFactory): implement FromMap")
+}
+
+func (k *WNodeFactory) Hasher() ifc.KunstructuredHasher {
+	panic("TODO(#WNodeFactory): implement Hasher")
+}
+
+func (k *WNodeFactory) MakeConfigMap(
+	kvLdr ifc.KvLoader, args *types.ConfigMapArgs) (ifc.Kunstructured, error) {
+	panic("TODO(#WNodeFactory): implement MakeConfigMap")
+}
+
+func (k *WNodeFactory) MakeSecret(
+	kvLdr ifc.KvLoader, args *types.SecretArgs) (ifc.Kunstructured, error) {
+	panic("TODO(#WNodeFactory): implement MakeSecret")
+}

api/internal/wrappy/factory_test.go

@@ -0,0 +1,4 @@
+// Copyright 2020 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package wrappy_test

api/internal/wrappy/wnode.go

@@ -0,0 +1,143 @@
+// Copyright 2020 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package wrappy
+
+import (
+	"log"
+
+	"sigs.k8s.io/kustomize/api/ifc"
+	"sigs.k8s.io/kustomize/api/resid"
+	"sigs.k8s.io/kustomize/kyaml/yaml"
+)
+
+// WNode implements ifc.Kunstructured using yaml.RNode.
+//
+// It exists only to help manage a switch from
+// kunstruct.UnstructAdapter to yaml.RNode as the core
+// representation of KRM objects in kustomize.
+//
+// It's got a silly name because we don't want it around for long,
+// and want its use to be obvious.
+type WNode struct {
+	node *yaml.RNode
+}
+
+var _ ifc.Kunstructured = (*WNode)(nil)
+
+func NewWNode() *WNode {
+	return FromRNode(yaml.NewRNode(nil))
+}
+
+func FromRNode(node *yaml.RNode) *WNode {
+	return &WNode{node: node}
+}
+
+func (wn *WNode) demandMetaData(label string) yaml.ResourceMeta {
+	meta, err := wn.node.GetMeta()
+	if err != nil {
+		// Log and die since interface doesn't allow error.
+		log.Fatalf("for %s', expected valid resource: %v", label, err)
+	}
+	return meta
+}
+
+// Copy implements ifc.Kunstructured.
+func (wn *WNode) Copy() ifc.Kunstructured {
+	return &WNode{node: wn.node.Copy()}
+}
+
+// GetAnnotations implements ifc.Kunstructured.
+func (wn *WNode) GetAnnotations() map[string]string {
+	return wn.demandMetaData("GetAnnotations").Annotations
+}
+
+// GetFieldValue implements ifc.Kunstructured.
+func (wn *WNode) GetFieldValue(path string) (interface{}, error) {
+	// The argument is a json path, e.g. "metadata.name"
+	// fields := strings.Split(path, ".")
+	// return wn.node.Pipe(yaml.Lookup(fields...))
+	panic("TODO(#WNode): GetFieldValue; implement or drop from API")
+}
+
+// GetGvk implements ifc.Kunstructured.
+func (wn *WNode) GetGvk() resid.Gvk {
+	meta := wn.demandMetaData("GetGvk")
+	g, v := resid.ParseGroupVersion(meta.APIVersion)
+	return resid.Gvk{Group: g, Version: v, Kind: meta.Kind}
+}
+
+// GetKind implements ifc.Kunstructured.
+func (wn *WNode) GetKind() string {
+	return wn.demandMetaData("GetKind").Kind
+}
+
+// GetLabels implements ifc.Kunstructured.
+func (wn *WNode) GetLabels() map[string]string {
+	return wn.demandMetaData("GetLabels").Labels
+}
+
+// GetName implements ifc.Kunstructured.
+func (wn *WNode) GetName() string {
+	return wn.demandMetaData("GetName").Name
+}
+
+// GetSlice implements ifc.Kunstructured.
+func (wn *WNode) GetSlice(string) ([]interface{}, error) {
+	panic("TODO(#WNode) GetSlice; implement or drop from API")
+}
+
+// GetSlice implements ifc.Kunstructured.
+func (wn *WNode) GetString(string) (string, error) {
+	panic("TODO(#WNode) GetString; implement or drop from API")
+}
+
+// Map implements ifc.Kunstructured.
+func (wn *WNode) Map() map[string]interface{} {
+	panic("TODO(#WNode) Map; implement or drop from API")
+}
+
+// MarshalJSON implements ifc.Kunstructured.
+func (wn *WNode) MarshalJSON() ([]byte, error) {
+	return wn.node.MarshalJSON()
+}
+
+// MatchesAnnotationSelector implements ifc.Kunstructured.
+func (wn *WNode) MatchesAnnotationSelector(string) (bool, error) {
+	panic("TODO(#WNode) MatchesAnnotationSelector; implement or drop from API")
+}
+
+// MatchesLabelSelector implements ifc.Kunstructured.
+func (wn *WNode) MatchesLabelSelector(string) (bool, error) {
+	panic("TODO(#WNode) MatchesLabelSelector; implement or drop from API")
+}
+
+// SetAnnotations implements ifc.Kunstructured.
+func (wn *WNode) SetAnnotations(map[string]string) {
+	panic("TODO(#WNode) SetAnnotations; implement or drop from API")
+}
+
+// SetGvk implements ifc.Kunstructured.
+func (wn *WNode) SetGvk(resid.Gvk) {
+	panic("TODO(#WNode) SetGvk; implement or drop from API")
+}
+
+// SetLabels implements ifc.Kunstructured.
+func (wn *WNode) SetLabels(map[string]string) {
+	panic("TODO(#WNode) SetLabels; implement or drop from API")
+}
+
+// SetName implements ifc.Kunstructured.
+func (wn *WNode) SetName(string) {
+	panic("TODO(#WNode) SetName; implement or drop from API")
+}
+
+// SetNamespace implements ifc.Kunstructured.
+func (wn *WNode) SetNamespace(string) {
+	panic("TODO(#WNode) SetNamespace; implement or drop from API")
+}
+
+// UnmarshalJSON implements ifc.Kunstructured.
+func (wn *WNode) UnmarshalJSON(data []byte) error {
+	return wn.node.UnmarshalJSON(data)
+}

api/internal/wrappy/wnode_test.go

@@ -0,0 +1,339 @@
+// Copyright 2019 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package wrappy_test
+
+import (
+	"strings"
+	"testing"
+
+	"gopkg.in/yaml.v3"
+	. "sigs.k8s.io/kustomize/api/internal/wrappy"
+	kyaml "sigs.k8s.io/kustomize/kyaml/yaml"
+)
+
+const (
+	deploymentLittleJson = `{"apiVersion":"apps/v1","kind":"Deployment",` +
+		`"metadata":{"name":"homer","namespace":"simpsons"}}`
+
+	deploymentBiggerJson = `
+{
+  "apiVersion": "apps/v1",
+  "kind": "Deployment",
+  "metadata": {
+    "name": "homer",
+    "namespace": "simpsons",
+    "labels": {
+      "fruit": "apple",
+      "veggie": "carrot"
+    },
+    "annotations": {
+      "area": "51",
+      "greeting": "Take me to your leader."
+    }
+  }
+}
+`
+	bigMapYaml = `Kind: Service
+complextree:
+  - field1:
+      - boolfield: true
+        floatsubfield: 1.01
+        intsubfield: 1010
+        stringsubfield: idx1010
+      - boolfield: false
+        floatsubfield: 1.011
+        intsubfield: 1011
+        stringsubfield: idx1011
+    field2:
+      - boolfield: true
+        floatsubfield: 1.02
+        intsubfield: 1020
+        stringsubfield: idx1020
+      - boolfield: false
+        floatsubfield: 1.021
+        intsubfield: 1021
+        stringsubfield: idx1021
+  - field1:
+      - boolfield: true
+        floatsubfield: 1.11
+        intsubfield: 1110
+        stringsubfield: idx1110
+      - boolfield: false
+        floatsubfield: 1.111
+        intsubfield: 1111
+        stringsubfield: idx1111
+    field2:
+      - boolfield: true
+        floatsubfield: 1.112
+        intsubfield: 1120
+        stringsubfield: idx1120
+      - boolfield: false
+        floatsubfield: 1.1121
+        intsubfield: 1121
+        stringsubfield: idx1121
+metadata:
+    labels:
+        app: application-name
+    name: service-name
+spec:
+    ports:
+        port: 80
+that:
+  - idx0
+  - idx1
+  - idx2
+  - idx3
+these:
+  - field1:
+      - idx010
+      - idx011
+    field2:
+      - idx020
+      - idx021
+  - field1:
+      - idx110
+      - idx111
+    field2:
+      - idx120
+      - idx121
+  - field1:
+      - idx210
+      - idx211
+    field2:
+      - idx220
+      - idx221
+this:
+    is:
+        aBool: true
+        aFloat: 1.001
+        aNilValue: null
+        aNumber: 1000
+        anEmptyMap: {}
+        anEmptySlice: []
+those:
+  - field1: idx0foo
+    field2: idx0bar
+  - field1: idx1foo
+    field2: idx1bar
+  - field1: idx2foo
+    field2: idx2bar
+`
+)
+
+func makeBigMap() map[string]interface{} {
+	return map[string]interface{}{
+		"Kind": "Service",
+		"metadata": map[string]interface{}{
+			"labels": map[string]interface{}{
+				"app": "application-name",
+			},
+			"name": "service-name",
+		},
+		"spec": map[string]interface{}{
+			"ports": map[string]interface{}{
+				"port": int64(80),
+			},
+		},
+		"this": map[string]interface{}{
+			"is": map[string]interface{}{
+				"aNumber":      int64(1000),
+				"aFloat":       float64(1.001),
+				"aNilValue":    nil,
+				"aBool":        true,
+				"anEmptyMap":   map[string]interface{}{},
+				"anEmptySlice": []interface{}{},
+				/*
+					TODO: test for unrecognizable (e.g. a function)
+						"unrecognizable": testing.InternalExample{
+							Name: "fooBar",
+						},
+				*/
+			},
+		},
+		"that": []interface{}{
+			"idx0",
+			"idx1",
+			"idx2",
+			"idx3",
+		},
+		"those": []interface{}{
+			map[string]interface{}{
+				"field1": "idx0foo",
+				"field2": "idx0bar",
+			},
+			map[string]interface{}{
+				"field1": "idx1foo",
+				"field2": "idx1bar",
+			},
+			map[string]interface{}{
+				"field1": "idx2foo",
+				"field2": "idx2bar",
+			},
+		},
+		"these": []interface{}{
+			map[string]interface{}{
+				"field1": []interface{}{"idx010", "idx011"},
+				"field2": []interface{}{"idx020", "idx021"},
+			},
+			map[string]interface{}{
+				"field1": []interface{}{"idx110", "idx111"},
+				"field2": []interface{}{"idx120", "idx121"},
+			},
+			map[string]interface{}{
+				"field1": []interface{}{"idx210", "idx211"},
+				"field2": []interface{}{"idx220", "idx221"},
+			},
+		},
+		"complextree": []interface{}{
+			map[string]interface{}{
+				"field1": []interface{}{
+					map[string]interface{}{
+						"stringsubfield": "idx1010",
+						"intsubfield":    int64(1010),
+						"floatsubfield":  float64(1.010),
+						"boolfield":      true,
+					},
+					map[string]interface{}{
+						"stringsubfield": "idx1011",
+						"intsubfield":    int64(1011),
+						"floatsubfield":  float64(1.011),
+						"boolfield":      false,
+					},
+				},
+				"field2": []interface{}{
+					map[string]interface{}{
+						"stringsubfield": "idx1020",
+						"intsubfield":    int64(1020),
+						"floatsubfield":  float64(1.020),
+						"boolfield":      true,
+					},
+					map[string]interface{}{
+						"stringsubfield": "idx1021",
+						"intsubfield":    int64(1021),
+						"floatsubfield":  float64(1.021),
+						"boolfield":      false,
+					},
+				},
+			},
+			map[string]interface{}{
+				"field1": []interface{}{
+					map[string]interface{}{
+						"stringsubfield": "idx1110",
+						"intsubfield":    int64(1110),
+						"floatsubfield":  float64(1.110),
+						"boolfield":      true,
+					},
+					map[string]interface{}{
+						"stringsubfield": "idx1111",
+						"intsubfield":    int64(1111),
+						"floatsubfield":  float64(1.111),
+						"boolfield":      false,
+					},
+				},
+				"field2": []interface{}{
+					map[string]interface{}{
+						"stringsubfield": "idx1120",
+						"intsubfield":    int64(1120),
+						"floatsubfield":  float64(1.1120),
+						"boolfield":      true,
+					},
+					map[string]interface{}{
+						"stringsubfield": "idx1121",
+						"intsubfield":    int64(1121),
+						"floatsubfield":  float64(1.1121),
+						"boolfield":      false,
+					},
+				},
+			},
+		},
+	}
+}
+
+func TestBasicYamlOperationFromMap(t *testing.T) {
+	bytes, err := yaml.Marshal(makeBigMap())
+	if err != nil {
+		t.Fatalf("unexpected yaml.Marshal err: %v", err)
+	}
+	if string(bytes) != bigMapYaml {
+		t.Fatalf("unexpected string equality")
+	}
+	rNode, err := kyaml.Parse(string(bytes))
+	if err != nil {
+		t.Fatalf("unexpected yaml.Marshal err: %v", err)
+	}
+	rNodeString := rNode.MustString()
+	// The result from MustString has more indentation
+	// than bigMapYaml.
+	rNodeStrings := strings.Split(rNodeString, "\n")
+	bigMapStrings := strings.Split(bigMapYaml, "\n")
+	if len(rNodeStrings) != len(bigMapStrings) {
+		t.Fatalf("line count mismatch")
+	}
+	for i := range rNodeStrings {
+		s1 := strings.TrimSpace(rNodeStrings[i])
+		s2 := strings.TrimSpace(bigMapStrings[i])
+		if s1 != s2 {
+			t.Fatalf("expected '%s'=='%s'", s1, s2)
+		}
+	}
+}
+
+func TestRoundTripJSON(t *testing.T) {
+	wn := NewWNode()
+	err := wn.UnmarshalJSON([]byte(deploymentLittleJson))
+	if err != nil {
+		t.Fatalf("unexpected UnmarshalJSON err: %v", err)
+	}
+	data, err := wn.MarshalJSON()
+	if err != nil {
+		t.Fatalf("unexpected MarshalJSON err: %v", err)
+	}
+	actual := string(data)
+	if actual != deploymentLittleJson {
+		t.Fatalf("expected %s, got %s", deploymentLittleJson, actual)
+	}
+}
+
+func TestGettingFields(t *testing.T) {
+	wn := NewWNode()
+	err := wn.UnmarshalJSON([]byte(deploymentBiggerJson))
+	if err != nil {
+		t.Fatalf("unexpected unmarshaljson err: %v", err)
+	}
+	gvk := wn.GetGvk()
+	expected := "apps"
+	actual := gvk.Group
+	if expected != actual {
+		t.Fatalf("expected '%s', got '%s'", expected, actual)
+	}
+	expected = "v1"
+	actual = gvk.Version
+	if expected != actual {
+		t.Fatalf("expected '%s', got '%s'", expected, actual)
+	}
+	expected = "Deployment"
+	actual = gvk.Kind
+	if expected != actual {
+		t.Fatalf("expected '%s', got '%s'", expected, actual)
+	}
+	actual = wn.GetKind()
+	if expected != actual {
+		t.Fatalf("expected '%s', got '%s'", expected, actual)
+	}
+	expected = "homer"
+	actual = wn.GetName()
+	if expected != actual {
+		t.Fatalf("expected '%s', got '%s'", expected, actual)
+	}
+	actualMap := wn.GetLabels()
+	v, ok := actualMap["fruit"]
+	if !ok || v != "apple" {
+		t.Fatalf("unexpected labels '%v'", actualMap)
+	}
+	actualMap = wn.GetAnnotations()
+	v, ok = actualMap["greeting"]
+	if !ok || v != "Take me to your leader." {
+		t.Fatalf("unexpected annotations '%v'", actualMap)
+	}
+}

api/k8sdeps/validator/kustvalidator.go

@@ -14,11 +14,14 @@ import (
 	v1validation "k8s.io/apimachinery/pkg/apis/meta/v1/validation"
 	"k8s.io/apimachinery/pkg/util/validation"
 	"k8s.io/apimachinery/pkg/util/validation/field"
+	"sigs.k8s.io/kustomize/api/ifc"
 )
 
 // KustValidator validates Labels and annotations by apimachinery
 type KustValidator struct{}
 
+var _ ifc.Validator = (*KustValidator)(nil)
+
 // NewKustValidator returns a KustValidator object
 func NewKustValidator() *KustValidator {
 	return &KustValidator{}

api/krusty/internal/provider/depprovider.go

@@ -0,0 +1,183 @@
+// Copyright 2020 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package provider
+
+import (
+	"sigs.k8s.io/kustomize/api/ifc"
+	"sigs.k8s.io/kustomize/api/internal/k8sdeps/merge"
+	kmerge "sigs.k8s.io/kustomize/api/internal/merge"
+	"sigs.k8s.io/kustomize/api/internal/validate"
+	"sigs.k8s.io/kustomize/api/internal/wrappy"
+	"sigs.k8s.io/kustomize/api/k8sdeps/kunstruct"
+	"sigs.k8s.io/kustomize/api/k8sdeps/validator"
+	"sigs.k8s.io/kustomize/api/resmap"
+	"sigs.k8s.io/kustomize/api/resource"
+)
+
+// DepProvider is a dependency provider.
+//
+// The instances it returns are either
+//   - old implementations backed by k8sdeps code,
+//   - new implementations backed by kyaml code.
+//
+// History:
+//
+// kubectl depends on k8s.io code, and at the time of writing, so
+// does kustomize.  Code that imports k8s.io/api* cannot be imported
+// back into k8s.io/*, yet kustomize appears inside k8s.io/kubectl.
+//
+// To allow kustomize to appear inside kubectl, yet still be developed
+// outside kubectl, the kustomize code was divided into the following
+// packages
+//
+//    api/
+//      k8sdeps/  (and internal/ks8deps/)
+//      ifc/
+//      krusty/
+//      everythingElse/
+//
+// with the following rules:
+//
+//   - Only k8sdeps/ may import k8s.io/api*.
+//
+//   - Only krusty/ (and its internals) may import k8sdeps/.
+//     I.e., ifc/ and everythingElse/ must not
+//     import k8sdeps/ or k8s.io/api*.
+//
+//   - Code in krusty/ may use code in k8sdeps/ to create
+//     objects then inject said objects into
+//     everythingElse/ behind dependency neutral interfaces.
+//
+// The idea was to periodically copy, not import, the large k8sdeps/
+// tree (plus a snippet from krusty/kustomizer.go) into the kubectl
+// codebase via a large PR, and have kubectl depend on the rest via
+// normal importing.
+//
+// Over 2019, however, kubectl underwent large changes including
+// a switch to Go modules, and a concerted attempt to extract kubectl
+// from the k8s repo. This made large kustomize integration PRs too
+// intrusive to review.
+//
+// In 2020, kubectl is based on Go modules, and almost entirely
+// extracted from the k8s.io repositories, and further the kyaml
+// library has a appeared as a viable replacement to k8s.io/api*
+// KRM manipulation code.
+//
+// The new plan is to eliminate k8sdeps/ entirely, along with its
+// k8s.io/api* dependence, allowing kustomize code to be imported
+// into kubectl via normal Go module imports.  Then the kustomize API
+// code can then move into the github.com/kubernetes-sigs/cli-utils
+// repo.  The kustomize CLI in github.com/kubernetes-sigs/kustomize
+// and the kubectl CLI can then both depend on the kustomize API.
+//
+// So, all code that depends on k8sdeps must go behind interfaces,
+// and kustomize must be factored to choose the implementation.
+//
+// That problem has been reduced to three interfaces, each having
+// two implementations. (1) is k8sdeps-based, (2) is kyaml-based.
+//
+//   - ifc.Kunstructured
+//
+//       1) api/k8sdeps/kunstruct.UnstructAdapter
+//
+//            This adapts structs in
+//            k8s.io/apimachinery/pkg/apis/meta/v1/unstructured
+//            to ifc.Kunstructured.
+//
+//       2) api/wrappy.WNode
+//
+//            This adapts sigs.k8s.io/kustomize/kyaml/yaml.RNode
+//            to ifc.Unstructured.
+//
+//            At time of writing, implementation started.
+//            Further reducing the size of ifc.Kunstructed
+//            would really reduce the work
+//            (e.g. drop Vars, drop ReplacementTranformer).
+//
+//   - resmap.Merginator
+//
+//       1) api/internal/k8sdeps/merge.Merginator
+//
+//            Uses k8s.io/apimachinery/pkg/util/strategicpatch,
+//            apimachinery/pkg/util/mergepatch, etc. to merge
+//            resource.Resource instances.
+//
+//       2) api/internal/merge.Merginator
+//
+//            At time of writing, this is unimplemented.
+//
+//   - ifc.Validator
+//
+//       1) api/k8sdeps/validator.KustValidator
+//
+//            Uses k8s.io/apimachinery/pkg/api/validation and
+//            friends to validate strings.
+//
+//       2) api/internal/validate.FieldValidator
+//
+//            At time of writing, this is a do-nothing
+//            validator as it's not critical to kustomize function.
+//
+// Proposed plan:
+//  [ ] Ship kustomize with the ability to switch from 1 to 2 via
+//      an --enable_kyaml flag.
+//  [ ] Make --enable_kyaml true by default.
+//  [ ] When 2 is not noticeably more buggy than 1, delete 1.
+//      I.e. delete k8sdeps/, transitively deleting all k8s.io/api* deps.
+//      This DepProvider should be left in place to retain these
+//      comments, but it will have only one choice.
+//  [ ] The way is now clear to reintegrate into kubectl.
+//      This should be done ASAP; the last step is cleanup.
+//  [ ] With only one impl of Kunstructure remaining, that interface
+//      and WNode can be deleted, along with this DepProvider.
+//      The other two interfaces could be dropped too.
+//
+// When the above is done, kustomize will use yaml.RNode and/or
+// KRM Config Functions directly and exclusively.
+// If you're reading this, plan not done.
+//
+type DepProvider struct {
+	resourceFactory *resource.Factory
+	merginator      resmap.Merginator
+	fieldValidator  ifc.Validator
+}
+
+func makeK8sdepBasedInstances() *DepProvider {
+	kf := kunstruct.NewKunstructuredFactoryImpl()
+	rf := resource.NewFactory(kf)
+	return &DepProvider{
+		resourceFactory: rf,
+		merginator:      merge.NewMerginator(rf),
+		fieldValidator:  validator.NewKustValidator(),
+	}
+}
+
+func makeKyamlBasedInstances() *DepProvider {
+	kf := &wrappy.WNodeFactory{}
+	rf := resource.NewFactory(kf)
+	return &DepProvider{
+		resourceFactory: rf,
+		merginator:      kmerge.NewMerginator(rf),
+		fieldValidator:  validate.NewFieldValidator(),
+	}
+}
+
+func NewDepProvider(useKyaml bool) *DepProvider {
+	if useKyaml {
+		return makeKyamlBasedInstances()
+	}
+	return makeK8sdepBasedInstances()
+}
+
+func (dp *DepProvider) GetResourceFactory() *resource.Factory {
+	return dp.resourceFactory
+}
+
+func (dp *DepProvider) GetMerginator() resmap.Merginator {
+	return dp.merginator
+}
+
+func (dp *DepProvider) GetFieldValidator() ifc.Validator {
+	return dp.fieldValidator
+}

api/krusty/kustomizer.go

@@ -8,16 +8,13 @@ import (
 
 	"sigs.k8s.io/kustomize/api/builtins"
 	"sigs.k8s.io/kustomize/api/filesys"
-	"sigs.k8s.io/kustomize/api/internal/k8sdeps/merge"
 	pLdr "sigs.k8s.io/kustomize/api/internal/plugins/loader"
 	"sigs.k8s.io/kustomize/api/internal/target"
-	"sigs.k8s.io/kustomize/api/k8sdeps/kunstruct"
-	"sigs.k8s.io/kustomize/api/k8sdeps/validator"
 	"sigs.k8s.io/kustomize/api/konfig"
+	"sigs.k8s.io/kustomize/api/krusty/internal/provider"
 	fLdr "sigs.k8s.io/kustomize/api/loader"
 	"sigs.k8s.io/kustomize/api/provenance"
 	"sigs.k8s.io/kustomize/api/resmap"
-	"sigs.k8s.io/kustomize/api/resource"
 	"sigs.k8s.io/kustomize/api/types"
 )
 
@@ -28,13 +25,18 @@ import (
 // number of overlays and bases), then make a Kustomizer
 // injected with the given fileystem, then call Run.
 type Kustomizer struct {
-	fSys    filesys.FileSystem
+	fSys        filesys.FileSystem
-	options *Options
+	options     *Options
+	depProvider *provider.DepProvider
 }
 
 // MakeKustomizer returns an instance of Kustomizer.
 func MakeKustomizer(fSys filesys.FileSystem, o *Options) *Kustomizer {
-	return &Kustomizer{fSys: fSys, options: o}
+	return &Kustomizer{
+		fSys:        fSys,
+		options:     o,
+		depProvider: provider.NewDepProvider(o.UseKyaml),
+	}
 }
 
 // Run performs a kustomization.
@@ -49,11 +51,9 @@ func MakeKustomizer(fSys filesys.FileSystem, o *Options) *Kustomizer {
 // on any number of internal paths (e.g. the filesystem may contain
 // multiple overlays, and Run can be called on each of them).
 func (b *Kustomizer) Run(path string) (resmap.ResMap, error) {
-	resourceFactory := resource.NewFactory(
-		kunstruct.NewKunstructuredFactoryImpl())
 	resmapFactory := resmap.NewFactory(
-		resourceFactory,
+		b.depProvider.GetResourceFactory(),
-		merge.NewMerginator(resourceFactory))
+		b.depProvider.GetMerginator())
 	lr := fLdr.RestrictionNone
 	if b.options.LoadRestrictions == types.LoadRestrictionsRootOnly {
 		lr = fLdr.RestrictionRootOnly
@@ -65,7 +65,7 @@ func (b *Kustomizer) Run(path string) (resmap.ResMap, error) {
 	defer ldr.Cleanup()
 	kt := target.NewKustTarget(
 		ldr,
-		validator.NewKustValidator(),
+		b.depProvider.GetFieldValidator(),
 		resmapFactory,
 		pLdr.NewLoader(b.options.PluginConfig, resmapFactory),
 	)

api/krusty/options.go

@@ -32,6 +32,10 @@ type Options struct {
 
 	// Options related to kustomize plugins.
 	PluginConfig *types.PluginConfig
+
+	// When true, use kyaml/ packages to manipulate KRM yaml.
+	// When false, use k8sdeps/ instead (uses k8s.io/api* packages).
+	UseKyaml bool
 }
 
 // MakeDefaultOptions returns a default instance of Options.
@@ -42,5 +46,6 @@ func MakeDefaultOptions() *Options {
 		LoadRestrictions:     types.LoadRestrictionsRootOnly,
 		DoPrune:              false,
 		PluginConfig:         konfig.DisabledPluginConfig(),
+		UseKyaml:             false,
 	}
 }

kustomize/internal/commands/build/build.go

@@ -95,6 +95,7 @@ func NewCmdBuild(out io.Writer) *cobra.Command {
 	addFlagEnablePlugins(cmd.Flags())
 	addFlagReorderOutput(cmd.Flags())
 	addFlagEnableManagedbyLabel(cmd.Flags())
+	addFlagEnableKyaml(cmd.Flags())
 
 	return cmd
 }
@@ -132,6 +133,7 @@ func (o *Options) makeOptions() *krusty.Options {
 		opts.PluginConfig = c
 	}
 	opts.AddManagedbyLabel = isManagedbyLabelEnabled()
+	opts.UseKyaml = flagEnableKyamlValue
 	return opts
 }
 

kustomize/internal/commands/build/flagEnableKyaml.go

@@ -0,0 +1,21 @@
+// Copyright 2019 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package build
+
+import (
+	"github.com/spf13/pflag"
+)
+
+var (
+	flagEnableKyamlValue = false
+)
+
+func addFlagEnableKyaml(set *pflag.FlagSet) {
+	set.BoolVar(
+		&flagEnableKyamlValue,
+		"enable_kyaml", // flag name
+		false,          // default value
+		"enable dependence on kyaml instead of k8sdeps.", // help
+	)
+}