Isolated content of pkg/kustomize

pkg/resource/util.go

@@ -0,0 +1,170 @@
+/*
+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 resource
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+
+	"github.com/golang/glog"
+
+	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
+	k8syaml "k8s.io/apimachinery/pkg/util/yaml"
+	"k8s.io/kubectl/pkg/kustomize/constants"
+)
+
+// decode decodes a list of objects in byte array format
+func decode(in []byte) ([]*Resource, error) {
+	decoder := k8syaml.NewYAMLOrJSONDecoder(bytes.NewReader(in), 1024)
+	resources := []*Resource{}
+
+	var err error
+	for {
+		var out unstructured.Unstructured
+		err = decoder.Decode(&out)
+		if err != nil {
+			break
+		}
+		resources = append(resources, &Resource{Data: &out})
+	}
+	if err != io.EOF {
+		return nil, err
+	}
+	return resources, nil
+}
+
+// decodeToResourceCollection decodes a list of objects in byte array format.
+// it will return a ResourceCollection.
+func decodeToResourceCollection(in []byte) (ResourceCollection, error) {
+	resources, err := decode(in)
+	if err != nil {
+		return nil, err
+	}
+
+	into := ResourceCollection{}
+	for _, res := range resources {
+		gvkn := res.GVKN()
+		if _, found := into[gvkn]; found {
+			return into, fmt.Errorf("GroupVersionKindName: %#v already exists in the map", gvkn)
+		}
+		into[gvkn] = res
+	}
+	return into, nil
+}
+
+func resourceCollectionFromResources(resources []*Resource) (ResourceCollection, error) {
+	out := ResourceCollection{}
+	for _, res := range resources {
+		gvkn := res.GVKN()
+		if _, found := out[gvkn]; found {
+			return nil, fmt.Errorf("duplicated %#v is not allowed", gvkn)
+		}
+		out[gvkn] = res
+	}
+	return out, nil
+}
+
+// Merge will merge all of the entries in the slice of ResourceCollection.
+func Merge(rcs ...ResourceCollection) (ResourceCollection, error) {
+	all := ResourceCollection{}
+	for _, rc := range rcs {
+		for gvkn, obj := range rc {
+			if _, found := all[gvkn]; found {
+				return nil, fmt.Errorf("there is already an entry: %q", gvkn)
+			}
+			all[gvkn] = obj
+		}
+	}
+
+	return all, nil
+}
+
+// MergeWithOverride will merge all of the entries in the slice of ResourceCollection with Override
+// If there is already an entry with the same GVKN exists, different actions are performed according to value of Behavior field
+// 'create': create a new one;
+// 'replace': replace the data only; keep the labels and annotations
+// 'merge': merge the data; keep the labels and annotations
+func MergeWithOverride(rcs ...ResourceCollection) (ResourceCollection, error) {
+	all := ResourceCollection{}
+
+	for _, rc := range rcs {
+		for gvkn, obj := range rc {
+			if _, found := all[gvkn]; found {
+				switch obj.Behavior {
+				case "", constants.CreateBehavior:
+					return nil, fmt.Errorf("Create an existing gvkn %#v is not allowed", gvkn)
+				case constants.ReplaceBehavior:
+					glog.V(4).Infof("Replace object %v by %v", all[gvkn].Data.Object, obj.Data.Object)
+					obj.replace(all[gvkn])
+					all[gvkn] = obj
+				case constants.MergeBehavior:
+					glog.V(4).Infof("Merge object %v with %v", all[gvkn].Data.Object, obj.Data.Object)
+					obj.merge(all[gvkn])
+					all[gvkn] = obj
+					glog.V(4).Infof("The merged object is %v", all[gvkn].Data.Object)
+				default:
+					return nil, fmt.Errorf("The behavior of %#v must be one of merge and replace since it already exists in the base", gvkn)
+				}
+			} else {
+				switch obj.Behavior {
+				case "", constants.CreateBehavior:
+					all[gvkn] = obj
+				case constants.MergeBehavior, constants.ReplaceBehavior:
+					return nil, fmt.Errorf("No merge or replace is allowed for non existing gvkn %#v", gvkn)
+				default:
+					return nil, fmt.Errorf("The behavior of %#v must be create since it doesn't exist", gvkn)
+				}
+			}
+		}
+	}
+	return all, nil
+}
+func (r *Resource) replace(other *Resource) {
+	r.Data.SetLabels(mergeMap(other.Data.GetLabels(), r.Data.GetLabels()))
+	r.Data.SetAnnotations(mergeMap(other.Data.GetAnnotations(), r.Data.GetAnnotations()))
+	r.Data.SetName(other.Data.GetName())
+}
+
+func (r *Resource) merge(other *Resource) {
+	r.replace(other)
+	mergeConfigmap(r.Data.Object, other.Data.Object, r.Data.Object)
+}
+
+func mergeMap(maps ...map[string]string) map[string]string {
+	mergedMap := map[string]string{}
+	for _, m := range maps {
+		for key, value := range m {
+			mergedMap[key] = value
+		}
+	}
+	return mergedMap
+}
+
+// TODO: Add BinaryData once we sync to new k8s.io/api
+func mergeConfigmap(mergedTo map[string]interface{}, maps ...map[string]interface{}) {
+	mergedMap := map[string]interface{}{}
+	for _, m := range maps {
+		datamap, ok := m["data"].(map[string]interface{})
+		if ok {
+			for key, value := range datamap {
+				mergedMap[key] = value
+			}
+		}
+	}
+	mergedTo["data"] = mergedMap
+}