/* Copyright 2021 The Dapr 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 kubernetes import ( "context" "encoding/json" "errors" "strconv" "sync" "sync/atomic" "time" v1 "k8s.io/api/core/v1" "k8s.io/apimachinery/pkg/fields" "k8s.io/client-go/kubernetes" "k8s.io/client-go/tools/cache" "github.com/dapr/components-contrib/bindings" kubeclient "github.com/dapr/components-contrib/internal/authentication/kubernetes" "github.com/dapr/kit/logger" ) type kubernetesInput struct { kubeClient kubernetes.Interface namespace string resyncPeriod time.Duration logger logger.Logger closed atomic.Bool closeCh chan struct{} wg sync.WaitGroup } type EventResponse struct { Event string `json:"event"` OldVal v1.Event `json:"oldVal"` NewVal v1.Event `json:"newVal"` } // NewKubernetes returns a new Kubernetes event input binding. func NewKubernetes(logger logger.Logger) bindings.InputBinding { return &kubernetesInput{ logger: logger, closeCh: make(chan struct{}), } } func (k *kubernetesInput) Init(ctx context.Context, metadata bindings.Metadata) error { client, err := kubeclient.GetKubeClient() if err != nil { return err } k.kubeClient = client return k.parseMetadata(metadata) } func (k *kubernetesInput) parseMetadata(metadata bindings.Metadata) error { if val, ok := metadata.Properties["namespace"]; ok && val != "" { k.namespace = val } else { return errors.New("namespace is missing in metadata") } if val, ok := metadata.Properties["resyncPeriodInSec"]; ok && val != "" { intval, err := strconv.ParseInt(val, 10, 64) if err != nil { k.logger.Warnf("invalid resyncPeriodInSec %s; %v; defaulting to 10s", val, err) k.resyncPeriod = time.Second * 10 } else { k.resyncPeriod = time.Second * time.Duration(intval) } } return nil } func (k *kubernetesInput) Read(ctx context.Context, handler bindings.Handler) error { if k.closed.Load() { return errors.New("binding is closed") } watchlist := cache.NewListWatchFromClient( k.kubeClient.CoreV1().RESTClient(), "events", k.namespace, fields.Everything(), ) resultChan := make(chan EventResponse) _, controller := cache.NewInformer( watchlist, &v1.Event{}, k.resyncPeriod, cache.ResourceEventHandlerFuncs{ AddFunc: func(obj interface{}) { if obj != nil { resultChan <- EventResponse{ Event: "add", NewVal: *(obj.(*v1.Event)), OldVal: v1.Event{}, } } else { k.logger.Warnf("Nil Object in Add handle %v", obj) } }, DeleteFunc: func(obj interface{}) { if obj != nil { resultChan <- EventResponse{ Event: "delete", OldVal: *(obj.(*v1.Event)), NewVal: v1.Event{}, } } else { k.logger.Warnf("Nil Object in Delete handle %v", obj) } }, UpdateFunc: func(oldObj, newObj interface{}) { if oldObj != nil && newObj != nil { resultChan <- EventResponse{ Event: "update", OldVal: *(oldObj.(*v1.Event)), NewVal: *(newObj.(*v1.Event)), } } else { k.logger.Warnf("Nil Objects in Update handle %v %v", oldObj, newObj) } }, }, ) k.wg.Add(3) readCtx, cancel := context.WithCancel(ctx) // catch when binding is closed. go func() { defer k.wg.Done() defer cancel() select { case <-readCtx.Done(): case <-k.closeCh: } }() // Start the controller in backgound go func() { defer k.wg.Done() controller.Run(readCtx.Done()) }() // Watch for new messages and for context cancellation go func() { defer k.wg.Done() var ( obj EventResponse data []byte err error ) for { select { case obj = <-resultChan: data, err = json.Marshal(obj) if err != nil { k.logger.Errorf("Error marshalling event %w", err) } else { handler(ctx, &bindings.ReadResponse{ Data: data, }) } case <-readCtx.Done(): return } } }() return nil } func (k *kubernetesInput) Close() error { if k.closed.CompareAndSwap(false, true) { close(k.closeCh) } k.wg.Wait() return nil }