generate configmap for pruning

pkg/commands/build/build.go

@@ -84,6 +84,8 @@ func NewCmdBuild(
 		&o.outputPath,
 		"output", "o", "",
 		"If specified, write the build output to this path.")
+
+	cmd.AddCommand(NewCmdBuildPrune(out, fs, rf, ptf, b))
 	return cmd
 }
 
@@ -130,3 +132,55 @@ func (o *Options) RunBuild(
 	_, err = out.Write(res)
 	return err
 }
+
+func (o *Options) RunBuildPrune(
+	out io.Writer, fSys fs.FileSystem,
+	rf *resmap.Factory, ptf transformer.Factory,
+	b bool) error {
+	ldr, err := loader.NewLoader(o.kustomizationPath, fSys)
+	if err != nil {
+		return err
+	}
+	defer ldr.Cleanup()
+	kt, err := target.NewKustTarget(ldr, rf, ptf, b)
+	if err != nil {
+		return err
+	}
+	allResources, err := kt.MakePruneConfigMap()
+	if err != nil {
+		return err
+	}
+	// Output the objects.
+	res, err := allResources.EncodeAsYaml()
+	if err != nil {
+		return err
+	}
+	if o.outputPath != "" {
+		return fSys.WriteFile(o.outputPath, res)
+	}
+	_, err = out.Write(res)
+	return err
+}
+
+func NewCmdBuildPrune(
+	out io.Writer, fs fs.FileSystem,
+	rf *resmap.Factory,
+	ptf transformer.Factory,
+	b bool) *cobra.Command {
+	var o Options
+
+	cmd := &cobra.Command{
+		Use:          "prune [path]",
+		Short:        "Print configmap to prune previous applied objects",
+		Example:      examples,
+		SilenceUsage: true,
+		RunE: func(cmd *cobra.Command, args []string) error {
+			err := o.Validate(args)
+			if err != nil {
+				return err
+			}
+			return o.RunBuildPrune(out, fs, rf, ptf, b)
+		},
+	}
+	return cmd
+}

pkg/commands/kustfile/kustomizationfile.go

@@ -69,6 +69,7 @@ func determineFieldOrder() []string {
 		"Configurations",
 		"Generators",
 		"Transformers",
+		"Prune",
 	}
 
 	// Add deprecated fields here.

pkg/commands/kustfile/kustomizationfile_test.go

@@ -48,6 +48,7 @@ func TestFieldOrder(t *testing.T) {
 		"Configurations",
 		"Generators",
 		"Transformers",
+		"Prune",
 	}
 	actual := determineFieldOrder()
 	if len(expected) != len(actual) {

pkg/ifc/transformer/factory.go

@@ -20,10 +20,12 @@ package transformer
 import (
 	"sigs.k8s.io/kustomize/pkg/resource"
 	"sigs.k8s.io/kustomize/pkg/transformers"
+	"sigs.k8s.io/kustomize/pkg/types"
 )
 
 // Factory makes transformers
 type Factory interface {
 	MakePatchTransformer(slice []*resource.Resource, rf *resource.Factory) (transformers.Transformer, error)
 	MakeHashTransformer() transformers.Transformer
+	MakePruneTransformer(p *types.Prune, namespace string, append bool) transformers.Transformer
 }

pkg/resid/resid.go

@@ -205,3 +205,13 @@ func (n ResId) prefixList() []string {
 func (n ResId) suffixList() []string {
 	return strings.Split(n.suffix, ":")
 }
+
+// PruneString returns a string which can be used
+// as a key in a Prune ConfigMap
+func (n ResId) PruneString() string {
+	name := n.prefix + n.name + n.suffix
+	return n.gvKind.Group +
+		"_" + n.gvKind.Kind +
+		"_" + n.namespace +
+		"_" + name
+}

pkg/resource/resource.go

@@ -30,6 +30,7 @@ import (
 type Resource struct {
 	ifc.Kunstructured
 	options *types.GenArgs
+	refBy   []resid.ResId
 }
 
 // String returns resource as JSON.
@@ -43,10 +44,16 @@ func (r *Resource) String() string {
 
 // DeepCopy returns a new copy of resource
 func (r *Resource) DeepCopy() *Resource {
-	return &Resource{
+	rc := &Resource{
 		Kunstructured: r.Kunstructured.Copy(),
 		options:       r.options,
 	}
+	if len(r.refBy) > 0 {
+		refby := make([]resid.ResId, len(r.refBy))
+		copy(refby, r.refBy)
+		rc.refBy = refby
+	}
+	return rc
 }
 
 // Behavior returns the behavior for the resource.
@@ -65,12 +72,26 @@ func (r *Resource) Id() resid.ResId {
 	return resid.NewResIdWithPrefixNamespace(r.GetGvk(), r.GetName(), "", namespace)
 }
 
+// GetRefBy returns the ResIds that referred to current resource
+func (r *Resource) GetRefBy() []resid.ResId {
+	return r.refBy
+}
+
+// AppendRefBy appends a ResId into the refBy list
+func (r *Resource) AppendRefBy(id resid.ResId) {
+	r.refBy = append(r.refBy, id)
+}
+
 // Merge performs merge with other resource.
 func (r *Resource) Merge(other *Resource) {
 	r.Replace(other)
 	mergeConfigmap(r.Map(), other.Map(), r.Map())
 }
 
+func (r *Resource) PruneString() string {
+	return r.Id().PruneString()
+}
+
 // Replace performs replace with other resource.
 func (r *Resource) Replace(other *Resource) {
 	r.SetLabels(mergeStringMaps(other.GetLabels(), r.GetLabels()))

pkg/resource/resource_test.go

@@ -17,6 +17,7 @@ limitations under the License.
 package resource_test
 
 import (
+	"reflect"
 	"testing"
 
 	"sigs.k8s.io/kustomize/k8sdeps/kunstruct"
@@ -94,3 +95,20 @@ func TestResourceId(t *testing.T) {
 		}
 	}
 }
+
+func TestDeepCopy(t *testing.T) {
+	r := factory.FromMap(
+		map[string]interface{}{
+			"apiVersion": "apps/v1",
+			"kind":       "Deployment",
+			"metadata": map[string]interface{}{
+				"name": "pooh",
+			},
+		})
+	r.AppendRefBy(resid.NewResId(gvk.Gvk{Group: "somegroup", Kind: "MyKind"}, "random"))
+
+	cr := r.DeepCopy()
+	if !reflect.DeepEqual(r, cr) {
+		t.Errorf("expected %v\nbut got%v", r, cr)
+	}
+}

pkg/target/kusttarget.go

@@ -143,7 +143,47 @@ func (kt *KustTarget) MakeCustomizedResMap() (resmap.ResMap, error) {
 	}
 	// With all the back references fixed, it's OK to resolve Vars.
 	err = ra.ResolveVars()
-	return ra.ResMap(), err
+	if err != nil {
+		return nil, err
+	}
+
+	rm := ra.ResMap()
+	pt := kt.tFactory.MakePruneTransformer(kt.kustomization.Prune, kt.kustomization.Namespace, true)
+	err = pt.Transform(rm)
+	if err != nil {
+		return nil, err
+	}
+	return rm, nil
+}
+
+func (kt *KustTarget) MakePruneConfigMap() (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.MakePruneTransformer(kt.kustomization.Prune, kt.kustomization.Namespace, false)
+	err = pt.Transform(rm)
+	if err != nil {
+		return nil, err
+	}
+	return rm, nil
 }
 
 func (kt *KustTarget) shouldAddHashSuffixesToGeneratedResources() bool {

pkg/target/pruneconfigmap_test.go

@@ -0,0 +1,180 @@
+/*
+Copyright 2018 The Kubernetes Authors.
+
+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 target_test
+
+import (
+	"testing"
+)
+
+func TestPruneConfigMap(t *testing.T) {
+	th := NewKustTestHarness(t, "/app/base")
+	th.writeK("/app/base", `
+resources:
+- deployment.yaml
+- service.yaml
+- secret.yaml
+
+prune:
+  type: alphaConfigMap
+  alphaConfigMap:
+    name: haha
+    namespace: default
+
+namePrefix: my-
+namespace: default
+`)
+	th.writeF("/app/base/deployment.yaml", `
+apiVersion: apps/v1beta2
+kind: Deployment
+metadata:
+  name: mysql
+  labels:
+    app: mysql
+spec:
+  selector:
+    matchLabels:
+      app: mysql
+  strategy:
+    type: Recreate
+  template:
+    metadata:
+      labels:
+        app: mysql
+    spec:
+      containers:
+      - image: mysql:5.6
+        name: mysql
+        env:
+        - name: MYSQL_ROOT_PASSWORD
+          valueFrom:
+            secretKeyRef:
+              name: pass
+              key: password
+        ports:
+        - containerPort: 3306
+          name: mysql
+        volumeMounts:
+        - name: mysql-persistent-storage
+          mountPath: /var/lib/mysql
+      volumes:
+      - name: mysql-persistent-storage
+        emptyDir: {}
+`)
+	th.writeF("/app/base/service.yaml", `
+apiVersion: v1
+kind: Service
+metadata:
+  name: mmmysql
+  labels:
+    app: mysql
+spec:
+  ports:
+    - port: 3306
+  selector:
+    app: mysql
+`)
+	th.writeF("/app/base/secret.yaml", `
+apiVersion: v1
+kind: Secret
+metadata:
+  name: pass
+type: Opaque
+data:
+  # Default password is "admin".
+  password: YWRtaW4=
+  username: jingfang
+`)
+
+	m, err := th.makeKustTarget().MakeCustomizedResMap()
+	if err != nil {
+		t.Fatalf("Err: %v", err)
+	}
+	th.assertActualEqualsExpected(m, `
+apiVersion: v1
+data:
+  _Secret_default_my-pass: 54f87m6fd6
+  _Secret_default_my-pass---apps_Deployment_default_my-mysql: 54f87m6fd6
+  _Service_default_my-mmmysql: 54f87m6fd6
+  apps_Deployment_default_my-mysql: 54f87m6fd6
+kind: ConfigMap
+metadata:
+  annotations:
+    current: 54f87m6fd6
+  name: haha
+  namespace: default
+---
+apiVersion: v1
+data:
+  password: YWRtaW4=
+  username: jingfang
+kind: Secret
+metadata:
+  name: my-pass
+  namespace: default
+type: Opaque
+---
+apiVersion: v1
+kind: Service
+metadata:
+  labels:
+    app: mysql
+  name: my-mmmysql
+  namespace: default
+spec:
+  ports:
+  - port: 3306
+  selector:
+    app: mysql
+---
+apiVersion: apps/v1beta2
+kind: Deployment
+metadata:
+  labels:
+    app: mysql
+  name: my-mysql
+  namespace: default
+spec:
+  selector:
+    matchLabels:
+      app: mysql
+  strategy:
+    type: Recreate
+  template:
+    metadata:
+      labels:
+        app: mysql
+    spec:
+      containers:
+      - env:
+        - name: MYSQL_ROOT_PASSWORD
+          valueFrom:
+            secretKeyRef:
+              key: password
+              name: my-pass
+        image: mysql:5.6
+        name: mysql
+        ports:
+        - containerPort: 3306
+          name: mysql
+        volumeMounts:
+        - mountPath: /var/lib/mysql
+          name: mysql-persistent-storage
+      volumes:
+      - emptyDir: {}
+        name: mysql-persistent-storage
+`)
+}

pkg/transformers/namereference.go

@@ -21,6 +21,7 @@ import (
 	"log"
 
 	"sigs.k8s.io/kustomize/pkg/gvk"
+	"sigs.k8s.io/kustomize/pkg/resid"
 	"sigs.k8s.io/kustomize/pkg/resmap"
 	"sigs.k8s.io/kustomize/pkg/transformers/config"
 )
@@ -70,7 +71,7 @@ func (o *nameReferenceTransformer) Transform(m resmap.ResMap) error {
 						m[id].Map(), fSpec.PathSlice(),
 						fSpec.CreateIfNotPresent,
 						o.updateNameReference(
-							backRef.Gvk, m.FilterBy(id)))
+							id, backRef.Gvk, m.FilterBy(id)))
 					if err != nil {
 						return err
 					}
@@ -82,7 +83,7 @@ func (o *nameReferenceTransformer) Transform(m resmap.ResMap) error {
 }
 
 func (o *nameReferenceTransformer) updateNameReference(
-	backRef gvk.Gvk, m resmap.ResMap) func(in interface{}) (interface{}, error) {
+	rid resid.ResId, backRef gvk.Gvk, m resmap.ResMap) func(in interface{}) (interface{}, error) {
 	return func(in interface{}) (interface{}, error) {
 		switch in.(type) {
 		case string:
@@ -98,6 +99,7 @@ func (o *nameReferenceTransformer) updateNameReference(
 					}
 					// Return transformed name of the object,
 					// complete with prefixes, hashes, etc.
+					res.AppendRefBy(rid)
 					return res.GetName(), nil
 				}
 			}
@@ -123,6 +125,7 @@ func (o *nameReferenceTransformer) updateNameReference(
 					for _, index := range indexes {
 						l[index] = res.GetName()
 					}
+					res.AppendRefBy(rid)
 					return l, nil
 				}
 			}

pkg/transformers/namereference_test.go

@@ -618,6 +618,7 @@ func TestNameReferencePersistentVolumeHappyRun(t *testing.T) {
 				},
 			}),
 	}
+	expected[resid.NewResId(pv, "volume1")].AppendRefBy(resid.NewResId(pvc, "claim1"))
 	nrt := NewNameReferenceTransformer(defaultTransformerConfig.NameReference)
 	err := nrt.Transform(m)
 	if err != nil {

pkg/types/kustomization.go

@@ -136,6 +136,9 @@ type Kustomization struct {
 
 	// Transformers is a list of files containing transformers
 	Transformers []string `json:"transformers,omitempty" yaml:"transformers,omitempty"`
+
+	// Name of the ConfigMap used in Prune
+	Prune *Prune `json:"prune,omitempty" yaml:"prune:omitempty"`
 }
 
 // DealWithMissingFields fills the missing fields
@@ -289,3 +292,13 @@ type KVSource struct {
 	Name       string     `json:"name,omitempty" yaml:"name,omitempty"`
 	Args       []string   `json:"args,omitempty" yaml:"args,omitempty"`
 }
+
+type Prune struct {
+	Type           string   `json:"type,omitempty" yaml:"type,omitempty"`
+	AlphaConfigMap NameArgs `json:"alphaConfigMap,omitempty" yaml:"alphaConfigMap,omitempty"`
+}
+
+type NameArgs struct {
+	Name      string `json:"name,omitempty" yaml:"name,omitempty"`
+	Namespace string `json:"namespace,omitempty" yaml:"namespace,omitempty"`
+}