change cluster schema (#2026)

* change cluster schema

* change cluster schema

vendor/sigs.k8s.io/kubefed/pkg/controller/util/overrides.go

@@ -0,0 +1,192 @@
+/*
+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 util
+
+import (
+	"encoding/json"
+
+	"github.com/evanphx/json-patch"
+	"github.com/pkg/errors"
+
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
+	"k8s.io/apimachinery/pkg/util/sets"
+)
+
+type ClusterOverride struct {
+	Op    string      `json:"op,omitempty"`
+	Path  string      `json:"path"`
+	Value interface{} `json:"value,omitempty"`
+}
+
+type GenericOverrideItem struct {
+	ClusterName      string            `json:"clusterName"`
+	ClusterOverrides []ClusterOverride `json:"clusterOverrides,omitempty"`
+}
+
+type GenericOverrideSpec struct {
+	Overrides []GenericOverrideItem `json:"overrides,omitempty"`
+}
+
+type GenericOverride struct {
+	metav1.TypeMeta   `json:",inline"`
+	metav1.ObjectMeta `json:"metadata,omitempty"`
+
+	Spec *GenericOverrideSpec `json:"spec,omitempty"`
+}
+
+// Namespace and name may not be overridden since these fields are the
+// primary mechanism of association between a federated resource in
+// the host cluster and the target resources in the member clusters.
+//
+// Kind should always be sourced from the FTC and not vary across
+// member clusters.
+//
+// apiVersion can be overridden to support managing resources like
+// Ingress which can exist in different groups at different
+// versions. Users will need to take care not to abuse this
+// capability.
+var invalidPaths = sets.NewString(
+	"/metadata/namespace",
+	"/metadata/name",
+	"/metadata/generateName",
+	"/kind",
+)
+
+// Slice of ClusterOverride
+type ClusterOverrides []ClusterOverride
+
+// Mapping of clusterName to overrides for the cluster
+type OverridesMap map[string]ClusterOverrides
+
+// ToUnstructuredSlice converts the map of overrides to a slice of
+// interfaces that can be set in an unstructured object.
+func (m OverridesMap) ToUnstructuredSlice() []interface{} {
+	overrides := []interface{}{}
+	for clusterName, clusterOverrides := range m {
+		overridesItem := map[string]interface{}{
+			ClusterNameField:      clusterName,
+			ClusterOverridesField: clusterOverrides,
+		}
+		overrides = append(overrides, overridesItem)
+	}
+	return overrides
+}
+
+// GetOverrides returns a map of overrides populated from the given
+// unstructured object.
+func GetOverrides(rawObj *unstructured.Unstructured) (OverridesMap, error) {
+	overridesMap := make(OverridesMap)
+
+	if rawObj == nil {
+		return overridesMap, nil
+	}
+
+	genericFedObject := GenericOverride{}
+	err := UnstructuredToInterface(rawObj, &genericFedObject)
+	if err != nil {
+		return nil, err
+	}
+
+	if genericFedObject.Spec == nil || genericFedObject.Spec.Overrides == nil {
+		// No overrides defined for the federated type
+		return overridesMap, nil
+	}
+
+	for _, overrideItem := range genericFedObject.Spec.Overrides {
+		clusterName := overrideItem.ClusterName
+		if _, ok := overridesMap[clusterName]; ok {
+			return nil, errors.Errorf("cluster %q appears more than once", clusterName)
+		}
+
+		clusterOverrides := overrideItem.ClusterOverrides
+
+		paths := sets.NewString()
+		for i, clusterOverride := range clusterOverrides {
+			path := clusterOverride.Path
+			if invalidPaths.Has(path) {
+				return nil, errors.Errorf("override[%d] for cluster %q has an invalid path: %s", i, clusterName, path)
+			}
+			if paths.Has(path) {
+				return nil, errors.Errorf("path %q appears more than once for cluster %q", path, clusterName)
+			}
+			paths.Insert(path)
+		}
+		overridesMap[clusterName] = clusterOverrides
+	}
+
+	return overridesMap, nil
+}
+
+// SetOverrides sets the spec.overrides field of the unstructured
+// object from the provided overrides map.
+func SetOverrides(fedObject *unstructured.Unstructured, overridesMap OverridesMap) error {
+	rawSpec := fedObject.Object[SpecField]
+	if rawSpec == nil {
+		rawSpec = map[string]interface{}{}
+		fedObject.Object[SpecField] = rawSpec
+	}
+
+	spec, ok := rawSpec.(map[string]interface{})
+	if !ok {
+		return errors.Errorf("Unable to set overrides since %q is not an object: %T", SpecField, rawSpec)
+	}
+	spec[OverridesField] = overridesMap.ToUnstructuredSlice()
+	return nil
+}
+
+// UnstructuredToInterface converts an unstructured object to the
+// provided interface by json marshalling/unmarshalling.
+func UnstructuredToInterface(rawObj *unstructured.Unstructured, obj interface{}) error {
+	content, err := rawObj.MarshalJSON()
+	if err != nil {
+		return err
+	}
+	return json.Unmarshal(content, obj)
+}
+
+// ApplyJsonPatch applies the override on to the given unstructured object.
+func ApplyJsonPatch(obj *unstructured.Unstructured, overrides ClusterOverrides) error {
+	// TODO: Do the defaulting of "op" field to "replace" in API defaulting
+	for i, overrideItem := range overrides {
+		if overrideItem.Op == "" {
+			overrides[i].Op = "replace"
+		}
+	}
+	jsonPatchBytes, err := json.Marshal(overrides)
+	if err != nil {
+		return err
+	}
+
+	patch, err := jsonpatch.DecodePatch(jsonPatchBytes)
+	if err != nil {
+		return err
+	}
+
+	ObjectJSONBytes, err := obj.MarshalJSON()
+	if err != nil {
+		return err
+	}
+
+	patchedObjectJSONBytes, err := patch.Apply(ObjectJSONBytes)
+	if err != nil {
+		return err
+	}
+
+	err = obj.UnmarshalJSON(patchedObjectJSONBytes)
+	return err
+}