Add json6902 patch filter based on kyaml libraries

api/builtins/PatchJson6902Transformer.go

@@ -8,10 +8,12 @@ import (
 
 	jsonpatch "github.com/evanphx/json-patch"
 	"github.com/pkg/errors"
+	"sigs.k8s.io/kustomize/api/filters/patchjson6902"
 	"sigs.k8s.io/kustomize/api/ifc"
 	"sigs.k8s.io/kustomize/api/resid"
 	"sigs.k8s.io/kustomize/api/resmap"
 	"sigs.k8s.io/kustomize/api/types"
+	"sigs.k8s.io/kustomize/kyaml/filtersutil"
 	"sigs.k8s.io/yaml"
 )
 
@@ -21,6 +23,8 @@ type PatchJson6902TransformerPlugin struct {
 	Target       types.PatchTarget `json:"target,omitempty" yaml:"target,omitempty"`
 	Path         string            `json:"path,omitempty" yaml:"path,omitempty"`
 	JsonOp       string            `json:"jsonOp,omitempty" yaml:"jsonOp,omitempty"`
+
+	YAMLSupport bool `json:"yamlSupport,omitempty" yaml:"yamlSupport,omitempty"`
 }
 
 func (p *PatchJson6902TransformerPlugin) Config(
@@ -83,16 +87,22 @@ func (p *PatchJson6902TransformerPlugin) Transform(m resmap.ResMap) error {
 	if err != nil {
 		return err
 	}
-	rawObj, err := obj.MarshalJSON()
-	if err != nil {
-		return err
+	if !p.YAMLSupport {
+		rawObj, err := obj.MarshalJSON()
+		if err != nil {
+			return err
+		}
+		modifiedObj, err := p.decodedPatch.Apply(rawObj)
+		if err != nil {
+			return errors.Wrapf(
+				err, "failed to apply json patch '%s'", p.JsonOp)
+		}
+		return obj.UnmarshalJSON(modifiedObj)
+	} else {
+		return filtersutil.ApplyToJSON(patchjson6902.Filter{
+			Patch: p.JsonOp,
+		}, obj.Kunstructured)
 	}
-	modifiedObj, err := p.decodedPatch.Apply(rawObj)
-	if err != nil {
-		return errors.Wrapf(
-			err, "failed to apply json patch '%s'", p.JsonOp)
-	}
-	return obj.UnmarshalJSON(modifiedObj)
 }
 
 func NewPatchJson6902TransformerPlugin() resmap.TransformerPlugin {

api/filters/patchjson6902/doc.go

@@ -0,0 +1,6 @@
+// Copyright 2020 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+// Package namespace contains a kio.Filter implementation of the kustomize
+// patchjson6902 transformer
+package patchjson6902

api/filters/patchjson6902/example_test.go

@@ -0,0 +1,55 @@
+// Copyright 2020 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package patchjson6902
+
+import (
+	"bytes"
+	"log"
+	"os"
+
+	"sigs.k8s.io/kustomize/kyaml/kio"
+)
+
+func ExampleFilter() {
+	err := kio.Pipeline{
+		Inputs: []kio.Reader{&kio.ByteReader{Reader: bytes.NewBufferString(`
+apiVersion: example.com/v1
+kind: Foo
+metadata:
+  name: instance
+---
+apiVersion: example.com/v1
+kind: Bar
+metadata:
+  name: instance
+  namespace: bar
+`)}},
+		Filters: []kio.Filter{
+			Filter{
+				Patch: `
+- op: replace
+  path: /metadata/namespace
+  value: "ns"
+`,
+			},
+		},
+		Outputs: []kio.Writer{kio.ByteWriter{Writer: os.Stdout}},
+	}.Execute()
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	// Output:
+	// apiVersion: example.com/v1
+	// kind: Foo
+	// metadata:
+	//   name: instance
+	//   namespace: ns
+	// ---
+	// apiVersion: example.com/v1
+	// kind: Bar
+	// metadata:
+	//   name: instance
+	//   namespace: ns
+}

api/filters/patchjson6902/patchjson6902.go

@@ -0,0 +1,65 @@
+// Copyright 2020 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package patchjson6902
+
+import (
+	"strings"
+
+	jsonpatch "github.com/evanphx/json-patch"
+	"sigs.k8s.io/kustomize/kyaml/kio"
+	"sigs.k8s.io/kustomize/kyaml/yaml"
+	k8syaml "sigs.k8s.io/yaml"
+)
+
+type Filter struct {
+	Patch string
+
+	decodedPatch jsonpatch.Patch
+}
+
+var _ kio.Filter = Filter{}
+
+func (pf Filter) Filter(nodes []*yaml.RNode) ([]*yaml.RNode, error) {
+	decodedPatch, err := pf.decodePatch()
+	if err != nil {
+		return nil, err
+	}
+	pf.decodedPatch = decodedPatch
+	return kio.FilterAll(yaml.FilterFunc(pf.run)).Filter(nodes)
+}
+
+func (pf Filter) decodePatch() (jsonpatch.Patch, error) {
+	patch := pf.Patch
+	// If the patch doesn't look like a JSON6902 patch, we
+	// try to parse it to json.
+	if !strings.HasPrefix(pf.Patch, "[") {
+		p, err := k8syaml.YAMLToJSON([]byte(patch))
+		if err != nil {
+			return nil, err
+		}
+		patch = string(p)
+	}
+	decodedPatch, err := jsonpatch.DecodePatch([]byte(patch))
+	if err != nil {
+		return nil, err
+	}
+	return decodedPatch, nil
+}
+
+func (pf Filter) run(node *yaml.RNode) (*yaml.RNode, error) {
+	// We don't actually use the kyaml library for manipulating the
+	// yaml here. We just marshal it to json and rely on the
+	// jsonpatch library to take care of applying the patch.
+	// This means ordering might not be preserved with this filter.
+	b, err := node.MarshalJSON()
+	if err != nil {
+		return nil, err
+	}
+	res, err := pf.decodedPatch.Apply(b)
+	if err != nil {
+		return nil, err
+	}
+	err = node.UnmarshalJSON(res)
+	return node, err
+}

api/filters/patchjson6902/patchjson6902_test.go

@@ -0,0 +1,173 @@
+// Copyright 2020 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package patchjson6902
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	filtertest "sigs.k8s.io/kustomize/api/testutils/filtertest"
+)
+
+const input = `
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: myDeploy
+spec:
+  replica: 2
+  template:
+    metadata:
+      labels:
+        old-label: old-value
+    spec:
+      containers:
+      - image: nginx
+        name: nginx
+`
+
+func TestSomething(t *testing.T) {
+	testCases := []struct {
+		testName       string
+		input          string
+		filter         Filter
+		expectedOutput string
+	}{
+		{
+			testName: "single operation, json",
+			input:    input,
+			filter: Filter{
+				Patch: `[
+{"op": "replace", "path": "/spec/replica", "value": 5}
+]`,
+			},
+			expectedOutput: `
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: myDeploy
+spec:
+  replica: 5
+  template:
+    metadata:
+      labels:
+        old-label: old-value
+    spec:
+      containers:
+      - image: nginx
+        name: nginx
+`,
+		},
+		{
+			testName: "multiple operations, json",
+			input:    input,
+			filter: Filter{
+				Patch: `[
+{"op": "replace", "path": "/spec/template/spec/containers/0/name", "value": "my-nginx"},
+{"op": "add", "path": "/spec/replica", "value": 999},
+{"op": "add", "path": "/spec/template/spec/containers/0/command", "value": ["arg1", "arg2", "arg3"]}
+]`,
+			},
+			expectedOutput: `
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: myDeploy
+spec:
+  replica: 999
+  template:
+    metadata:
+      labels:
+        old-label: old-value
+    spec:
+      containers:
+      - command:
+        - arg1
+        - arg2
+        - arg3
+        image: nginx
+        name: my-nginx
+`,
+		},
+		{
+			testName: "single operation, yaml",
+			input:    input,
+			filter: Filter{
+				Patch: `
+- op: replace
+  path: /spec/replica
+  value: 5
+`,
+			},
+			expectedOutput: `
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: myDeploy
+spec:
+  replica: 5
+  template:
+    metadata:
+      labels:
+        old-label: old-value
+    spec:
+      containers:
+      - image: nginx
+        name: nginx
+`,
+		},
+		{
+			testName: "multiple operations, yaml",
+			input:    input,
+			filter: Filter{
+				Patch: `
+- op: replace
+  path: /spec/template/spec/containers/0/name
+  value: my-nginx
+- op: add
+  path: /spec/replica
+  value: 999
+- op: add
+  path: /spec/template/spec/containers/0/command
+  value:
+  - arg1
+  - arg2
+  - arg3
+`,
+			},
+			expectedOutput: `
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: myDeploy
+spec:
+  replica: 999
+  template:
+    metadata:
+      labels:
+        old-label: old-value
+    spec:
+      containers:
+      - command:
+        - arg1
+        - arg2
+        - arg3
+        image: nginx
+        name: my-nginx
+`,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.testName, func(t *testing.T) {
+			if !assert.Equal(t,
+				strings.TrimSpace(tc.expectedOutput),
+				strings.TrimSpace(
+					filtertest.RunFilter(t, tc.input, tc.filter))) {
+				t.FailNow()
+			}
+		})
+	}
+}

api/go.mod

@@ -16,6 +16,6 @@ require (
 	k8s.io/apimachinery v0.17.0
 	k8s.io/client-go v0.17.0
 	k8s.io/kube-openapi v0.0.0-20191107075043-30be4d16710a
-	sigs.k8s.io/kustomize/kyaml v0.1.3
+	sigs.k8s.io/kustomize/kyaml v0.1.5
 	sigs.k8s.io/yaml v1.1.0
 )

api/go.sum

@@ -513,6 +513,8 @@ sigs.k8s.io/kustomize/kyaml v0.1.1/go.mod h1:/NdPPfrperSCGjm55cwEro1loBVtbtVIXSb
 sigs.k8s.io/kustomize/kyaml v0.1.2 h1:l12+QGl+ETUHhP8/bZAi6TknU7H194fXL/9b2gUxZFY=
 sigs.k8s.io/kustomize/kyaml v0.1.3 h1:zbeHVTMCQPtWgjIH/YYJZC45mm7coTdw2TblyJ79BrY=
 sigs.k8s.io/kustomize/kyaml v0.1.3/go.mod h1:461i94nj0h0ylJ6w83jLkR4SqqVhn1iY6fjD0JSTQeE=
+sigs.k8s.io/kustomize/kyaml v0.1.5 h1:NicBWYTwkuOfVyZDbNkfSBSCwSgin4uirkedtyZltIc=
+sigs.k8s.io/kustomize/kyaml v0.1.5/go.mod h1:461i94nj0h0ylJ6w83jLkR4SqqVhn1iY6fjD0JSTQeE=
 sigs.k8s.io/structured-merge-diff v0.0.0-20190525122527-15d366b2352e/go.mod h1:wWxsB5ozmmv/SG7nM11ayaAW51xMvak/t1r0CSlcokI=
 sigs.k8s.io/yaml v1.1.0 h1:4A07+ZFc2wgJwo8YNlQpr1rVlgUDlxXHhPJciaPY5gs=
 sigs.k8s.io/yaml v1.1.0/go.mod h1:UJmg0vDUVViEyp3mgSv9WPwZCDxu4rQW1olrI1uml+o=