k8s.io/apiserver@v0.31.1/pkg/storage/cacher/lister_watcher.go (about) 1 /* 2 Copyright 2023 The Kubernetes Authors. 3 4 Licensed under the Apache License, Version 2.0 (the "License"); 5 you may not use this file except in compliance with the License. 6 You may obtain a copy of the License at 7 8 http://www.apache.org/licenses/LICENSE-2.0 9 10 Unless required by applicable law or agreed to in writing, software 11 distributed under the License is distributed on an "AS IS" BASIS, 12 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 See the License for the specific language governing permissions and 14 limitations under the License. 15 */ 16 17 package cacher 18 19 import ( 20 "context" 21 22 "google.golang.org/grpc/metadata" 23 24 metav1 "k8s.io/apimachinery/pkg/apis/meta/v1" 25 "k8s.io/apimachinery/pkg/fields" 26 "k8s.io/apimachinery/pkg/labels" 27 "k8s.io/apimachinery/pkg/runtime" 28 "k8s.io/apimachinery/pkg/watch" 29 "k8s.io/apiserver/pkg/storage" 30 "k8s.io/client-go/tools/cache" 31 ) 32 33 // listerWatcher opaques storage.Interface to expose cache.ListerWatcher. 34 type listerWatcher struct { 35 storage storage.Interface 36 resourcePrefix string 37 newListFunc func() runtime.Object 38 contextMetadata metadata.MD 39 } 40 41 // NewListerWatcher returns a storage.Interface backed ListerWatcher. 42 func NewListerWatcher(storage storage.Interface, resourcePrefix string, newListFunc func() runtime.Object, contextMetadata metadata.MD) cache.ListerWatcher { 43 return &listerWatcher{ 44 storage: storage, 45 resourcePrefix: resourcePrefix, 46 newListFunc: newListFunc, 47 contextMetadata: contextMetadata, 48 } 49 } 50 51 // Implements cache.ListerWatcher interface. 52 func (lw *listerWatcher) List(options metav1.ListOptions) (runtime.Object, error) { 53 list := lw.newListFunc() 54 pred := storage.SelectionPredicate{ 55 Label: labels.Everything(), 56 Field: fields.Everything(), 57 Limit: options.Limit, 58 Continue: options.Continue, 59 } 60 61 storageOpts := storage.ListOptions{ 62 ResourceVersionMatch: options.ResourceVersionMatch, 63 Predicate: pred, 64 Recursive: true, 65 } 66 ctx := context.Background() 67 if lw.contextMetadata != nil { 68 ctx = metadata.NewOutgoingContext(ctx, lw.contextMetadata) 69 } 70 if err := lw.storage.GetList(ctx, lw.resourcePrefix, storageOpts, list); err != nil { 71 return nil, err 72 } 73 return list, nil 74 } 75 76 // Implements cache.ListerWatcher interface. 77 func (lw *listerWatcher) Watch(options metav1.ListOptions) (watch.Interface, error) { 78 opts := storage.ListOptions{ 79 ResourceVersion: options.ResourceVersion, 80 Predicate: storage.Everything, 81 Recursive: true, 82 ProgressNotify: true, 83 } 84 ctx := context.Background() 85 if lw.contextMetadata != nil { 86 ctx = metadata.NewOutgoingContext(ctx, lw.contextMetadata) 87 } 88 return lw.storage.Watch(ctx, lw.resourcePrefix, opts) 89 }