forked from rook/rook
Steve Leon
709b7ddafe
- Use CRD for clusters and pools - For k8s before 1.7.0, TPR will be used - Also use the watcher libraries in client-go
91 lines
2.9 KiB
Go
91 lines
2.9 KiB
Go
/*
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Copyright 2016 The Rook Authors. All rights reserved.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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Some of the code was modified from https://github.com/coreos/etcd-operator
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which also has the apache 2.0 license.
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*/
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// Package kit for Kubernetes operators
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package kit
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import (
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"errors"
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"k8s.io/api/core/v1"
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"k8s.io/apimachinery/pkg/fields"
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"k8s.io/apimachinery/pkg/runtime"
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"k8s.io/client-go/rest"
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"k8s.io/client-go/tools/cache"
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)
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var (
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// ErrVersionOutdated indicates that the custom resource is outdated and needs to be refreshed
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ErrVersionOutdated = errors.New("requested version is outdated in apiserver")
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)
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// ResourceWatcher watches a custom resource for desired state
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type ResourceWatcher struct {
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resource CustomResource
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namespace string
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resourceEventHandlers cache.ResourceEventHandlerFuncs
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client *rest.RESTClient
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scheme *runtime.Scheme
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}
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// NewWatcher creates an instance of a custom resource watcher for the given resource
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func NewWatcher(resource CustomResource, namespace string, handlers cache.ResourceEventHandlerFuncs, client *rest.RESTClient) *ResourceWatcher {
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return &ResourceWatcher{
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resource: resource,
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namespace: namespace,
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resourceEventHandlers: handlers,
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client: client,
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}
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}
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// Watch begins watching the custom resource (TPR/CRD). The call will block until a Done signal is raised during in the context.
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// When the watch has detected a create, update, or delete event, it will handled by the functions in the resourceEventHandlers. After the callback returns, the watch loop will continue for the next event.
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// If the callback returns an error, the error will be logged.
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func (w *ResourceWatcher) Watch(objType runtime.Object, done chan struct{}) error {
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if w.namespace == v1.NamespaceAll {
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logger.Infof("start watching %s resource in all namespaces at %s", w.resource.Name, w.resource.Version)
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} else {
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logger.Infof("start watching %s resource in namespace %s at %s", w.resource.Name, w.namespace, w.resource.Version)
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}
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source := cache.NewListWatchFromClient(
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w.client,
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w.resource.Plural,
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w.namespace,
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fields.Everything())
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_, controller := cache.NewInformer(
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source,
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// The object type.
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objType,
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// resyncPeriod
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// Every resyncPeriod, all resources in the cache will retrigger events.
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// Set to 0 to disable the resync.
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0,
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// Your custom resource event handlers.
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w.resourceEventHandlers)
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go controller.Run(done)
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<-done
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return nil
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}
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