From 6a3e3c3a717a64df13f5d73af01d71b156eccde5 Mon Sep 17 00:00:00 2001
From: Jingfang Liu <jingfangliu@google.com>
Date: Thu, 23 Aug 2018 12:23:55 -0700
Subject: [PATCH] Add JSONPatch to kustomization

---
 pkg/app/application.go     | 11 +++++++++--
 pkg/types/jsonpatch.go     | 39 ++++++++++++++++++++++++++++++++++++++
 pkg/types/kustomization.go | 11 +++++++++--
 3 files changed, 57 insertions(+), 4 deletions(-)
 create mode 100644 pkg/types/jsonpatch.go

diff --git a/pkg/app/application.go b/pkg/app/application.go
index 32e7d052d..5a2145b85 100644
--- a/pkg/app/application.go
+++ b/pkg/app/application.go
@@ -22,6 +22,7 @@ import (
 	"bytes"
 	"encoding/json"
 	"fmt"
+	"log"
 
 	"github.com/ghodss/yaml"
 	"github.com/golang/glog"
@@ -61,7 +62,12 @@ func NewApplication(ldr loader.Loader, fSys fs.FileSystem) (*Application, error)
 	if err != nil {
 		return nil, err
 	}
-
+	if m.PatchesJson6902 != nil {
+		log.Printf("field patchesJson6902 ignored; no implementation yet.")
+	}
+	if m.Patches != nil {
+		log.Println("field patches will be deprecated, please change it to patchesStategicMerge")
+	}
 	return &Application{kustomization: &m, ldr: ldr, fSys: fSys}, nil
 }
 
@@ -150,7 +156,8 @@ func (a *Application) loadCustomizedResMap() (resmap.ResMap, error) {
 		return nil, err
 	}
 
-	patches, err := resmap.NewResourceSliceFromPatches(a.ldr, a.kustomization.Patches)
+	a.kustomization.PatchesStrategicMerge = append(a.kustomization.PatchesStrategicMerge, a.kustomization.Patches...)
+	patches, err := resmap.NewResourceSliceFromPatches(a.ldr, a.kustomization.PatchesStrategicMerge)
 	if err != nil {
 		errs.Append(errors.Wrap(err, "NewResourceSliceFromPatches"))
 	}
diff --git a/pkg/types/jsonpatch.go b/pkg/types/jsonpatch.go
new file mode 100644
index 000000000..81efbbf91
--- /dev/null
+++ b/pkg/types/jsonpatch.go
@@ -0,0 +1,39 @@
+/*
+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 types
+
+// JSONPatch represents a json patch for an object
+type JSONPatch struct {
+	// Relative file path within the kustomization for a json patch file.
+	Path string `json:"path" yaml:"path"`
+
+	// Target refers to a Kubernetes object that the json patch will be
+	// applied to. It must refer to a Kubernetes resource under the
+	// purview of this kustomization. Target should use the
+	// raw name of the object (the name specified in its YAML,
+	// before addition of a namePrefix).
+	Target PatchTarget `json:"target" yaml:"target"`
+}
+
+// PatchTarget represents the kubernetes object that the patch is applied to
+type PatchTarget struct {
+	Group     string `json:"group,omitempty" yaml:"group,omitempty"`
+	Version   string `json:"version,omitempty" yaml:"version,omitempty"`
+	Kind      string `json:"kind,omitempty" yaml:"kind,omitempty"`
+	Namespace string `json:"namespace,omitempty" yaml:"namespace,omitempty"`
+	Name      string `json:"name" yaml:"name"`
+}
diff --git a/pkg/types/kustomization.go b/pkg/types/kustomization.go
index 3a5807eda..beb6920eb 100644
--- a/pkg/types/kustomization.go
+++ b/pkg/types/kustomization.go
@@ -56,8 +56,15 @@ type Kustomization struct {
 
 	// An Patch entry is very similar to an Resource entry.
 	// It specifies the relative paths for patch files within the package.
-	// URLs and globs are not supported
-	Patches []string `json:"patches,omitempty" yaml:"patches,omitempty"`
+	// URLs and globs are not supported.
+	// The patch files should be Stategic Merge Patch, the default patching behavior for kubectl.
+	// https://github.com/kubernetes/community/blob/master/contributors/devel/strategic-merge-patch.md
+	Patches               []string `json:"patches,omitempty" yaml:"patches,omitempty"`
+	PatchesStrategicMerge []string `json:"patchesSrategicMerge,omitempty" yaml:"patchesStategicMerge,omitempty"`
+
+	// JSONPatches is a list of JSONPatch for applying JSON patch.
+	// The JSON patch is documented at http://jsonpatch.com/.
+	PatchesJson6902 []JSONPatch `json:"patchesJson6902,omitempty" yaml:"patchesJson6902,omitempty"`
 
 	// List of configmaps to generate from configuration sources.
 	// Base/overlay concept doesn't apply to this field.