Rename OverlayTranformer to PatchTransformer.

pkg/transformers/patchconflictdetector.go

@@ -0,0 +1,130 @@
+/*
+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 transformers
+
+import (
+	"encoding/json"
+
+	"github.com/evanphx/json-patch"
+
+	"github.com/kubernetes-sigs/kustomize/pkg/resource"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/util/mergepatch"
+	"k8s.io/apimachinery/pkg/util/strategicpatch"
+)
+
+type conflictDetector interface {
+	hasConflict(patch1, patch2 *resource.Resource) (bool, error)
+	findConflict(conflictingPatchIdx int, patches []*resource.Resource) (*resource.Resource, error)
+	mergePatches(patch1, patch2 *resource.Resource) (*resource.Resource, error)
+}
+
+type jsonMergePatch struct{}
+
+var _ conflictDetector = &jsonMergePatch{}
+
+func newJMPConflictDetector() conflictDetector {
+	return &jsonMergePatch{}
+}
+
+func (jmp *jsonMergePatch) hasConflict(patch1, patch2 *resource.Resource) (bool, error) {
+	return mergepatch.HasConflicts(patch1.Object, patch2.Object)
+}
+
+func (jmp *jsonMergePatch) findConflict(conflictingPatchIdx int, patches []*resource.Resource) (*resource.Resource, error) {
+	for i, patch := range patches {
+		if i == conflictingPatchIdx {
+			continue
+		}
+		if patches[conflictingPatchIdx].GroupVersionKind() != patch.GroupVersionKind() ||
+			patches[conflictingPatchIdx].GetName() != patch.GetName() {
+			continue
+		}
+		conflict, err := mergepatch.HasConflicts(patch.Object, patches[conflictingPatchIdx].Object)
+		if err != nil {
+			return nil, err
+		}
+		if conflict {
+			return patch, nil
+		}
+	}
+	return nil, nil
+}
+
+func (jmp *jsonMergePatch) mergePatches(patch1, patch2 *resource.Resource) (*resource.Resource, error) {
+	var merged resource.Resource
+	var mergedMap map[string]interface{}
+	baseBytes, err := json.Marshal(patch1.Object)
+	if err != nil {
+		return nil, err
+	}
+	patchBytes, err := json.Marshal(patch2.Object)
+	if err != nil {
+		return nil, err
+	}
+	mergedBytes, err := jsonpatch.MergeMergePatches(baseBytes, patchBytes)
+	if err != nil {
+		return nil, err
+	}
+	err = json.Unmarshal(mergedBytes, &mergedMap)
+	merged.SetUnstructuredContent(mergedMap)
+	return &merged, err
+}
+
+type strategicMergePatch struct {
+	lookupPatchMeta strategicpatch.LookupPatchMeta
+}
+
+var _ conflictDetector = &strategicMergePatch{}
+
+func newSMPConflictDetector(versionedObj runtime.Object) (conflictDetector, error) {
+	lookupPatchMeta, err := strategicpatch.NewPatchMetaFromStruct(versionedObj)
+	return &strategicMergePatch{lookupPatchMeta: lookupPatchMeta}, err
+}
+
+func (smp *strategicMergePatch) hasConflict(patch1, patch2 *resource.Resource) (bool, error) {
+	return strategicpatch.MergingMapsHaveConflicts(patch1.Object, patch2.Object, smp.lookupPatchMeta)
+}
+
+func (smp *strategicMergePatch) findConflict(conflictingPatchIdx int, patches []*resource.Resource) (*resource.Resource, error) {
+	for i, patch := range patches {
+		if i == conflictingPatchIdx {
+			continue
+		}
+		if patches[conflictingPatchIdx].GroupVersionKind() != patch.GroupVersionKind() ||
+			patches[conflictingPatchIdx].GetName() != patch.GetName() {
+			continue
+		}
+		conflict, err := strategicpatch.MergingMapsHaveConflicts(
+			patch.Object, patches[conflictingPatchIdx].Object, smp.lookupPatchMeta)
+		if err != nil {
+			return nil, err
+		}
+		if conflict {
+			return patch, nil
+		}
+	}
+	return nil, nil
+}
+
+func (smp *strategicMergePatch) mergePatches(patch1, patch2 *resource.Resource) (*resource.Resource, error) {
+	merged := resource.Resource{}
+	mergeJsonMap, err := strategicpatch.MergeStrategicMergeMapPatchUsingLookupPatchMeta(
+		smp.lookupPatchMeta, patch1.Object, patch2.Object)
+	merged.SetUnstructuredContent(mergeJsonMap)
+	return &merged, err
+}