Add patchJson6902 transformer

pkg/patch/transformer/patchjson6902json.go

@@ -0,0 +1,94 @@
+/*
+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 transformer
+
+import (
+	"fmt"
+	"log"
+
+	jsonpatch "github.com/evanphx/json-patch"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+
+	"github.com/kubernetes-sigs/kustomize/pkg/patch"
+	"github.com/kubernetes-sigs/kustomize/pkg/resmap"
+	"github.com/kubernetes-sigs/kustomize/pkg/resource"
+	"github.com/kubernetes-sigs/kustomize/pkg/transformers"
+)
+
+// patchJson6902Transformer applies patches.
+type patchJson6902JSONTransformer struct {
+	target     *patch.Target
+	operations []byte
+}
+
+var _ transformers.Transformer = &patchJson6902JSONTransformer{}
+
+// NewPatchJson6902JSONTransformer constructs a PatchJson6902 transformer.
+func NewPatchJson6902JSONTransformer(t *patch.Target, o []byte) (transformers.Transformer, error) {
+	return &patchJson6902JSONTransformer{target: t, operations: o}, nil
+}
+
+// Transform apply the json patches on top of the base resources.
+func (t *patchJson6902JSONTransformer) Transform(baseResourceMap resmap.ResMap) error {
+	targetId := resource.NewResIdWithPrefixNamespace(
+		schema.GroupVersionKind{
+			Group:   t.target.Group,
+			Version: t.target.Version,
+			Kind:    t.target.Kind,
+		},
+		t.target.Name,
+		"",
+		t.target.Namespace,
+	)
+
+	matchedIds := baseResourceMap.FindByGVKN(targetId)
+	if targetId.Namespace() != "" {
+		ids := []resource.ResId{}
+		for _, id := range matchedIds {
+			if id.Namespace() == targetId.Namespace() {
+				ids = append(ids, id)
+			}
+		}
+		matchedIds = ids
+	}
+	if len(matchedIds) == 0 {
+		log.Printf("Couldn't find any object to apply the json patch %v, skipping it.", targetId)
+		return nil
+	}
+	if len(matchedIds) > 1 {
+		return fmt.Errorf("found multiple objects that the patch can apply %v", matchedIds)
+	}
+
+	decodedPatch, err := jsonpatch.DecodePatch(t.operations)
+	if err != nil {
+		return err
+	}
+	obj := baseResourceMap[matchedIds[0]]
+	rawObj, err := obj.Unstructured.MarshalJSON()
+	if err != nil {
+		return err
+	}
+	modifiedObj, err := decodedPatch.Apply(rawObj)
+	if err != nil {
+		return err
+	}
+	err = obj.UnmarshalJSON(modifiedObj)
+	if err != nil {
+		return err
+	}
+	return nil
+}