1/* 2Copyright 2021 The Kubernetes Authors. 3 4Licensed under the Apache License, Version 2.0 (the "License"); 5you may not use this file except in compliance with the License. 6You may obtain a copy of the License at 7 8 http://www.apache.org/licenses/LICENSE-2.0 9 10Unless required by applicable law or agreed to in writing, software 11distributed under the License is distributed on an "AS IS" BASIS, 12WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13See the License for the specific language governing permissions and 14limitations under the License. 15*/ 16 17package managedfields 18 19import ( 20 "bytes" 21 "fmt" 22 23 "sigs.k8s.io/structured-merge-diff/v4/fieldpath" 24 "sigs.k8s.io/structured-merge-diff/v4/typed" 25 26 "k8s.io/apimachinery/pkg/api/meta" 27 metav1 "k8s.io/apimachinery/pkg/apis/meta/v1" 28 "k8s.io/apimachinery/pkg/apis/meta/v1/unstructured" 29 "k8s.io/apimachinery/pkg/runtime" 30) 31 32// ExtractInto extracts the applied configuration state from object for fieldManager 33// into applyConfiguration. If no managed fields are found for the given fieldManager, 34// no error is returned, but applyConfiguration is left unpopulated. It is possible 35// that no managed fields were found for the fieldManager because other field managers 36// have taken ownership of all the fields previously owned by the fieldManager. It is 37// also possible the fieldManager never owned fields. 38func ExtractInto(object runtime.Object, objectType typed.ParseableType, fieldManager string, applyConfiguration interface{}) error { 39 typedObj, err := toTyped(object, objectType) 40 if err != nil { 41 return fmt.Errorf("error converting obj to typed: %w", err) 42 } 43 44 accessor, err := meta.Accessor(object) 45 if err != nil { 46 return fmt.Errorf("error accessing metadata: %w", err) 47 } 48 fieldsEntry, ok := findManagedFields(accessor, fieldManager) 49 if !ok { 50 return nil 51 } 52 fieldset := &fieldpath.Set{} 53 err = fieldset.FromJSON(bytes.NewReader(fieldsEntry.FieldsV1.Raw)) 54 if err != nil { 55 return fmt.Errorf("error marshalling FieldsV1 to JSON: %w", err) 56 } 57 58 u := typedObj.ExtractItems(fieldset.Leaves()).AsValue().Unstructured() 59 m, ok := u.(map[string]interface{}) 60 if !ok { 61 return fmt.Errorf("unable to convert managed fields for %s to unstructured, expected map, got %T", fieldManager, u) 62 } 63 if err := runtime.DefaultUnstructuredConverter.FromUnstructured(m, applyConfiguration); err != nil { 64 return fmt.Errorf("error extracting into obj from unstructured: %w", err) 65 } 66 return nil 67} 68 69func findManagedFields(accessor metav1.Object, fieldManager string) (metav1.ManagedFieldsEntry, bool) { 70 objManagedFields := accessor.GetManagedFields() 71 for _, mf := range objManagedFields { 72 if mf.Manager == fieldManager && mf.Operation == metav1.ManagedFieldsOperationApply { 73 return mf, true 74 } 75 } 76 return metav1.ManagedFieldsEntry{}, false 77} 78 79func toTyped(obj runtime.Object, objectType typed.ParseableType) (*typed.TypedValue, error) { 80 switch o := obj.(type) { 81 case *unstructured.Unstructured: 82 return objectType.FromUnstructured(o.Object) 83 default: 84 return objectType.FromStructured(o) 85 } 86} 87