Implement "kind: KustomizationPatch" to support composition of Kustomize files

api/internal/target/kusttarget.go

@@ -155,8 +155,12 @@ func (kt *KustTarget) addHashesToNames(
 // not yet fixed.
 func (kt *KustTarget) AccumulateTarget() (
 	ra *accumulator.ResAccumulator, err error) {
-	ra = accumulator.MakeEmptyAccumulator()
+	return kt.accumulateTarget(accumulator.MakeEmptyAccumulator())
-	err = kt.accumulateResources(ra, kt.kustomization.Resources)
+}
+
+func (kt *KustTarget) accumulateTarget(ra *accumulator.ResAccumulator) (
+	resRa *accumulator.ResAccumulator, err error) {
+	ra, err = kt.accumulateResources(ra, kt.kustomization.Resources)
 	if err != nil {
 		return nil, errors.Wrap(err, "accumulating resources")
 	}
@@ -224,7 +228,7 @@ func (kt *KustTarget) runGenerators(
 
 func (kt *KustTarget) configureExternalGenerators() ([]resmap.Generator, error) {
 	ra := accumulator.MakeEmptyAccumulator()
-	err := kt.accumulateResources(ra, kt.kustomization.Generators)
+	ra, err := kt.accumulateResources(ra, kt.kustomization.Generators)
 	if err != nil {
 		return nil, err
 	}
@@ -250,7 +254,7 @@ func (kt *KustTarget) runTransformers(ra *accumulator.ResAccumulator) error {
 
 func (kt *KustTarget) configureExternalTransformers() ([]resmap.Transformer, error) {
 	ra := accumulator.MakeEmptyAccumulator()
-	err := kt.accumulateResources(ra, kt.kustomization.Transformers)
+	ra, err := kt.accumulateResources(ra, kt.kustomization.Transformers)
 	if err != nil {
 		return nil, err
 	}
@@ -260,44 +264,52 @@ func (kt *KustTarget) configureExternalTransformers() ([]resmap.Transformer, err
 // accumulateResources fills the given resourceAccumulator
 // with resources read from the given list of paths.
 func (kt *KustTarget) accumulateResources(
-	ra *accumulator.ResAccumulator, paths []string) error {
+	ra *accumulator.ResAccumulator, paths []string) (*accumulator.ResAccumulator, error) {
 	for _, path := range paths {
 		// try loading resource as file then as base (directory or git repository)
 		if errF := kt.accumulateFile(ra, path); errF != nil {
 			ldr, errL := kt.ldr.New(path)
 			if errL != nil {
-				return fmt.Errorf("accumulateFile %q, loader.New %q", errF, errL)
+				return nil, fmt.Errorf("accumulateFile %q, loader.New %q", errF, errL)
 			}
-			errD := kt.accumulateDirectory(ra, ldr)
+			var errD error
+			ra, errD = kt.accumulateDirectory(ra, ldr)
 			if errD != nil {
-				return fmt.Errorf("accumulateFile %q, accumulateDirector: %q", errF, errD)
+				return nil, fmt.Errorf("accumulateFile %q, accumulateDirector: %q", errF, errD)
 			}
 		}
 	}
-	return nil
+	return ra, nil
 }
 
 func (kt *KustTarget) accumulateDirectory(
-	ra *accumulator.ResAccumulator, ldr ifc.Loader) error {
+	ra *accumulator.ResAccumulator, ldr ifc.Loader) (*accumulator.ResAccumulator, error) {
 	defer ldr.Cleanup()
 	subKt := NewKustTarget(
 		ldr, kt.validator, kt.rFactory, kt.tFactory, kt.pLdr)
 	err := subKt.Load()
 	if err != nil {
-		return errors.Wrapf(
+		return nil, errors.Wrapf(
 			err, "couldn't make target for path '%s'", ldr.Root())
 	}
-	subRa, err := subKt.AccumulateTarget()
+
+	var subRa *accumulator.ResAccumulator
+	if subKt.kustomization.Kind == types.KustomizationPatchKind {
+		subRa, err = subKt.accumulateTarget(ra)
+		ra = accumulator.MakeEmptyAccumulator()
+	} else {
+		subRa, err = subKt.AccumulateTarget()
+	}
 	if err != nil {
-		return errors.Wrapf(
+		return nil, errors.Wrapf(
 			err, "recursed accumulation of path '%s'", ldr.Root())
 	}
 	err = ra.MergeAccumulator(subRa)
 	if err != nil {
-		return errors.Wrapf(
+		return nil, errors.Wrapf(
 			err, "recursed merging from path '%s'", ldr.Root())
 	}
-	return nil
+	return ra, nil
 }
 
 func (kt *KustTarget) accumulateFile(

api/krusty/kustomizationpatch_test.go

@@ -0,0 +1,334 @@
+// Copyright 2019 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package krusty_test
+
+import (
+	"testing"
+
+	kusttest_test "sigs.k8s.io/kustomize/api/testutils/kusttest"
+)
+
+// Test kustomization.yaml files with  kind: KustomizationPatch
+func writeKustomizationPatchBase(th kusttest_test.Harness) {
+	th.WriteK("/app/base", `
+resources:
+- deploy.yaml
+configMapGenerator:
+- name: my-configmap
+  literals:	
+    - testValue=1
+    - otherValue=10
+`)
+	th.WriteF("/app/base/deploy.yaml", `
+apiVersion: v1
+kind: Deployment
+metadata:
+  name: storefront
+spec:
+  replicas: 1
+`)
+}
+
+func writeKustomizationPatchPatch(th kusttest_test.Harness) {
+	th.WriteF("/app/patch/kustomization.yaml", `
+apiVersion: kustomize.config.k8s.io/v1beta1
+kind: KustomizationPatch
+namePrefix: patched-
+replicas:
+- name: storefront
+  count: 3
+resources:
+  - stub.yaml
+configMapGenerator:
+- name: my-configmap
+  behavior: merge
+  literals:	
+    - testValue=2
+    - patchValue=5
+`)
+	th.WriteF("/app/patch/stub.yaml", `
+apiVersion: v1
+kind: Deployment
+metadata:
+  name: stub
+spec:
+  replicas: 1
+`)
+}
+
+func writeKustomizationPatchProd(th kusttest_test.Harness) {
+	th.WriteK("/app/prod", `
+resources:
+- ../base
+- ../patch
+- db
+`)
+	th.WriteF("/app/prod/db", `
+apiVersion: v1
+kind: Deployment
+metadata:
+  name: db
+spec:
+  type: Logical
+`)
+}
+
+// KustomizationPatch are inserted into the resource hierarchy as the parent of those
+// resources that come before it in the resources list of the parent Kustomization.
+func TestBasicKustomizationPatch(t *testing.T) {
+	th := kusttest_test.MakeHarness(t)
+	writeKustomizationPatchBase(th)
+	writeKustomizationPatchPatch(th)
+	writeKustomizationPatchProd(th)
+	m := th.Run("/app/prod", th.MakeDefaultOptions())
+	th.AssertActualEqualsExpected(m, `
+apiVersion: v1
+kind: Deployment
+metadata:
+  name: patched-storefront
+spec:
+  replicas: 3
+---
+apiVersion: v1
+data:
+  otherValue: "10"
+  patchValue: "5"
+  testValue: "2"
+kind: ConfigMap
+metadata:
+  annotations: {}
+  labels: {}
+  name: patched-my-configmap-5g55h28cdh
+---
+apiVersion: v1
+kind: Deployment
+metadata:
+  name: patched-stub
+spec:
+  replicas: 1
+---
+apiVersion: v1
+kind: Deployment
+metadata:
+  name: db
+spec:
+  type: Logical
+`)
+}
+
+func TestMultipleKustomizationPatches(t *testing.T) {
+	th := kusttest_test.MakeHarness(t)
+	writeKustomizationPatchBase(th)
+	writeKustomizationPatchPatch(th)
+	writeKustomizationPatchProd(th)
+	th.WriteF("/app/additionalpatch/kustomization.yaml", `
+apiVersion: kustomize.config.k8s.io/v1beta1
+kind: KustomizationPatch
+configMapGenerator:
+- name: my-configmap
+  behavior: merge
+  literals:	
+    - otherValue=9
+`)
+	th.WriteK("/app/prod", `
+resources:
+- ../base
+- ../patch
+- ../additionalpatch
+- db
+`)
+	m := th.Run("/app/prod", th.MakeDefaultOptions())
+	th.AssertActualEqualsExpected(m, `
+apiVersion: v1
+kind: Deployment
+metadata:
+  name: patched-storefront
+spec:
+  replicas: 3
+---
+apiVersion: v1
+data:
+  otherValue: "9"
+  patchValue: "5"
+  testValue: "2"
+kind: ConfigMap
+metadata:
+  annotations: {}
+  labels: {}
+  name: patched-my-configmap-9fddc87cdk
+---
+apiVersion: v1
+kind: Deployment
+metadata:
+  name: patched-stub
+spec:
+  replicas: 1
+---
+apiVersion: v1
+kind: Deployment
+metadata:
+  name: db
+spec:
+  type: Logical
+`)
+}
+
+func TestNestedKustomizationPatches(t *testing.T) {
+	th := kusttest_test.MakeHarness(t)
+	writeKustomizationPatchBase(th)
+	writeKustomizationPatchPatch(th)
+	writeKustomizationPatchProd(th)
+	th.WriteF("/app/additionalpatch/kustomization.yaml", `
+apiVersion: kustomize.config.k8s.io/v1beta1
+kind: KustomizationPatch
+resources:
+- ../patch
+configMapGenerator:
+- name: my-configmap
+  behavior: merge
+  literals:	
+    - otherValue=9
+`)
+	th.WriteK("/app/prod", `
+resources:
+- ../base
+- ../additionalpatch
+- db
+`)
+	m := th.Run("/app/prod", th.MakeDefaultOptions())
+	th.AssertActualEqualsExpected(m, `
+apiVersion: v1
+kind: Deployment
+metadata:
+  name: patched-storefront
+spec:
+  replicas: 3
+---
+apiVersion: v1
+data:
+  otherValue: "9"
+  patchValue: "5"
+  testValue: "2"
+kind: ConfigMap
+metadata:
+  annotations: {}
+  labels: {}
+  name: patched-my-configmap-9fddc87cdk
+---
+apiVersion: v1
+kind: Deployment
+metadata:
+  name: patched-stub
+spec:
+  replicas: 1
+---
+apiVersion: v1
+kind: Deployment
+metadata:
+  name: db
+spec:
+  type: Logical
+`)
+}
+
+// If a patch sets a name prefix on a base, then that base can also be separately included
+// without being affected by the patch in another branch of the resource tree
+func TestBasicKustomizationPatchWithRepeatedBase(t *testing.T) {
+	th := kusttest_test.MakeHarness(t)
+	writeKustomizationPatchBase(th)
+	writeKustomizationPatchPatch(th)
+	writeKustomizationPatchProd(th)
+	th.WriteK("/app/repeated", `
+resources:
+- ../base
+- ../prod
+`)
+	m := th.Run("/app/repeated", th.MakeDefaultOptions())
+	th.AssertActualEqualsExpected(m, `
+apiVersion: v1
+kind: Deployment
+metadata:
+  name: storefront
+spec:
+  replicas: 1
+---
+apiVersion: v1
+data:
+  otherValue: "10"
+  testValue: "1"
+kind: ConfigMap
+metadata:
+  name: my-configmap-7k9t4h74f8
+---
+apiVersion: v1
+kind: Deployment
+metadata:
+  name: patched-storefront
+spec:
+  replicas: 3
+---
+apiVersion: v1
+data:
+  otherValue: "10"
+  patchValue: "5"
+  testValue: "2"
+kind: ConfigMap
+metadata:
+  annotations: {}
+  labels: {}
+  name: patched-my-configmap-5g55h28cdh
+---
+apiVersion: v1
+kind: Deployment
+metadata:
+  name: patched-stub
+spec:
+  replicas: 1
+---
+apiVersion: v1
+kind: Deployment
+metadata:
+  name: db
+spec:
+  type: Logical
+`)
+}
+
+func TestApplyingKustomizationPatchDirectlySameAsKustomization(t *testing.T) {
+	th := kusttest_test.MakeHarness(t)
+	writeKustomizationPatchBase(th)
+	writeKustomizationPatchPatch(th)
+	th.WriteF("/app/solopatch/kustomization.yaml", `
+apiVersion: kustomize.config.k8s.io/v1beta1
+kind: KustomizationPatch
+resources:
+- ../base
+configMapGenerator:
+- name: my-configmap
+  behavior: merge
+  literals:	
+    - patchValue=5
+    - testValue=2
+`)
+	m := th.Run("/app/solopatch", th.MakeDefaultOptions())
+	th.AssertActualEqualsExpected(m, `
+apiVersion: v1
+kind: Deployment
+metadata:
+  name: storefront
+spec:
+  replicas: 1
+---
+apiVersion: v1
+data:
+  otherValue: "10"
+  patchValue: "5"
+  testValue: "2"
+kind: ConfigMap
+metadata:
+  annotations: {}
+  labels: {}
+  name: my-configmap-t86ktk6tdk
+`)
+}

api/types/kustomization.go

@@ -4,9 +4,10 @@
 package types
 
 const (
-	KustomizationVersion  = "kustomize.config.k8s.io/v1beta1"
+	KustomizationVersion   = "kustomize.config.k8s.io/v1beta1"
-	KustomizationKind     = "Kustomization"
+	KustomizationKind      = "Kustomization"
-	MetadataNamespacePath = "metadata/namespace"
+	KustomizationPatchKind = "KustomizationPatch"
+	MetadataNamespacePath  = "metadata/namespace"
 )
 
 // Kustomization holds the information needed to generate customized k8s api resources.
@@ -143,8 +144,8 @@ func (k *Kustomization) EnforceFields() []string {
 	if k.APIVersion != "" && k.APIVersion != KustomizationVersion {
 		errs = append(errs, "apiVersion should be "+KustomizationVersion)
 	}
-	if k.Kind != "" && k.Kind != KustomizationKind {
+	if k.Kind != "" && k.Kind != KustomizationKind && k.Kind != KustomizationPatchKind {
-		errs = append(errs, "kind should be "+KustomizationKind)
+		errs = append(errs, "kind should be "+KustomizationKind+" or "+KustomizationPatchKind)
 	}
 	return errs
 }