用网站建设费用,建站优化公司,做文字logo的网站,ui设计的工作流程sample-controller
sample-controller 是 K8s 官方自定义 CDR 及控制器是实现的例子
通过使用这个自定义 CDR 控制器及阅读它的代码#xff0c;基本可以了解如何制作一个 CDR 控制器
CDR 运作原理
网上有更好的文章#xff0c;说明其运作原理#xff1a;
https://www.z…sample-controller
sample-controller 是 K8s 官方自定义 CDR 及控制器是实现的例子
通过使用这个自定义 CDR 控制器及阅读它的代码基本可以了解如何制作一个 CDR 控制器
CDR 运作原理
网上有更好的文章说明其运作原理
https://www.zhaohuabing.com/post/2023-03-09-how-to-create-a-k8s-controller/https://www.zhaohuabing.com/post/2023-04-04-how-to-create-a-k8s-controller-2/
CDR 定义 yaml 文件格式细节
官方文档 https://kubernetes.io/zh-cn/docs/tasks/extend-kubernetes/custom-resources/custom-resource-definitions/
sample-controller 目录文件说明
fananchongmyubuntu:~/k8s.io/sample-controller$ tree -L 2
.
|-- artifacts
| -- examples # CRD yaml 文件定义例子
|-- controller.go # 控制器实现
|-- hack # k8s.io/code-generator 提供的生成 pkg/generated/ 、 pkg/apis/samplecontroller/v1alpha1/zz_generated.deepcopy.go
| |-- boilerplate.go.txt
| |-- custom-boilerplate.go.txt
| |-- tools.go
| |-- update-codegen.sh
| -- verify-codegen.sh
|-- main.go # main 函数
|-- pkg
| |-- apis # k8s.io/code-generator 根据 types.go 、 doc.go 来生成
| |-- generated # 自动生成
| -- signals
-- vendor # go mod vendor|-- github.com|-- golang.org|-- google.golang.org|-- gopkg.in|-- k8s.io|-- modules.txt-- sigs.k8s.iocontroller.go 关键代码分析 Informer 监听事件 fooInformer 监听 Foo CDR 事件 deploymentInformer 监听 Deployment 事件 // Set up an event handler for when Foo resources changefooInformer.Informer().AddEventHandler(cache.ResourceEventHandlerFuncs{AddFunc: controller.enqueueFoo,UpdateFunc: func(old, new interface{}) {controller.enqueueFoo(new)},})// Set up an event handler for when Deployment resources change. This// handler will lookup the owner of the given Deployment, and if it is// owned by a Foo resource then the handler will enqueue that Foo resource for// processing. This way, we dont need to implement custom logic for// handling Deployment resources. More info on this pattern:// https://github.com/kubernetes/community/blob/8cafef897a22026d42f5e5bb3f104febe7e29830/contributors/devel/controllers.mddeploymentInformer.Informer().AddEventHandler(cache.ResourceEventHandlerFuncs{AddFunc: controller.handleObject,UpdateFunc: func(old, new interface{}) {newDepl : new.(*appsv1.Deployment)oldDepl : old.(*appsv1.Deployment)if newDepl.ResourceVersion oldDepl.ResourceVersion {// Periodic resync will send update events for all known Deployments.// Two different versions of the same Deployment will always have different RVs.return}controller.handleObject(new)},DeleteFunc: controller.handleObject,})Foo CDR 事件处理 压入工作队列 // enqueueFoo takes a Foo resource and converts it into a namespace/name
// string which is then put onto the work queue. This method should *not* be
// passed resources of any type other than Foo.
func (c *Controller) enqueueFoo(obj interface{}) {var key stringvar err errorif key, err cache.MetaNamespaceKeyFunc(obj); err ! nil {utilruntime.HandleError(err)return}c.workqueue.Add(key)
}Deployment 事件处理 判断是属于 Foo 控制器创建的 Deployment 压入队列 // handleObject will take any resource implementing metav1.Object and attempt
// to find the Foo resource that owns it. It does this by looking at the
// objects metadata.ownerReferences field for an appropriate OwnerReference.
// It then enqueues that Foo resource to be processed. If the object does not
// have an appropriate OwnerReference, it will simply be skipped.
func (c *Controller) handleObject(obj interface{}) {var object metav1.Objectvar ok boollogger : klog.FromContext(context.Background())if object, ok obj.(metav1.Object); !ok {tombstone, ok : obj.(cache.DeletedFinalStateUnknown)if !ok {utilruntime.HandleError(fmt.Errorf(error decoding object, invalid type))return}object, ok tombstone.Obj.(metav1.Object)if !ok {utilruntime.HandleError(fmt.Errorf(error decoding object tombstone, invalid type))return}logger.V(4).Info(Recovered deleted object, resourceName, object.GetName())}logger.V(4).Info(Processing object, object, klog.KObj(object))if ownerRef : metav1.GetControllerOf(object); ownerRef ! nil {// If this object is not owned by a Foo, we should not do anything more// with it.if ownerRef.Kind ! Foo {return}foo, err : c.foosLister.Foos(object.GetNamespace()).Get(ownerRef.Name)if err ! nil {logger.V(4).Info(Ignore orphaned object, object, klog.KObj(object), foo, ownerRef.Name)return}c.enqueueFoo(foo)return}
}Controller.Run 处理 从队列中取出元素 如果副本预期不一致做 scale 处理 // syncHandler compares the actual state with the desired, and attempts to
// converge the two. It then updates the Status block of the Foo resource
// with the current status of the resource.
func (c *Controller) syncHandler(ctx context.Context, key string) error {// Convert the namespace/name string into a distinct namespace and namelogger : klog.LoggerWithValues(klog.FromContext(ctx), resourceName, key)namespace, name, err : cache.SplitMetaNamespaceKey(key)if err ! nil {utilruntime.HandleError(fmt.Errorf(invalid resource key: %s, key))return nil}// Get the Foo resource with this namespace/namefoo, err : c.foosLister.Foos(namespace).Get(name)if err ! nil {// The Foo resource may no longer exist, in which case we stop// processing.if errors.IsNotFound(err) {utilruntime.HandleError(fmt.Errorf(foo %s in work queue no longer exists, key))return nil}return err}deploymentName : foo.Spec.DeploymentNameif deploymentName {// We choose to absorb the error here as the worker would requeue the// resource otherwise. Instead, the next time the resource is updated// the resource will be queued again.utilruntime.HandleError(fmt.Errorf(%s: deployment name must be specified, key))return nil}// Get the deployment with the name specified in Foo.specdeployment, err : c.deploymentsLister.Deployments(foo.Namespace).Get(deploymentName)// If the resource doesnt exist, well create itif errors.IsNotFound(err) {deployment, err c.kubeclientset.AppsV1().Deployments(foo.Namespace).Create(context.TODO(), newDeployment(foo), metav1.CreateOptions{})}// If an error occurs during Get/Create, well requeue the item so we can// attempt processing again later. This could have been caused by a// temporary network failure, or any other transient reason.if err ! nil {return err}// If the Deployment is not controlled by this Foo resource, we should log// a warning to the event recorder and return error msg.if !metav1.IsControlledBy(deployment, foo) {msg : fmt.Sprintf(MessageResourceExists, deployment.Name)c.recorder.Event(foo, corev1.EventTypeWarning, ErrResourceExists, msg)return fmt.Errorf(%s, msg)}// If this number of the replicas on the Foo resource is specified, and the// number does not equal the current desired replicas on the Deployment, we// should update the Deployment resource.if foo.Spec.Replicas ! nil *foo.Spec.Replicas ! *deployment.Spec.Replicas {logger.V(4).Info(Update deployment resource, currentReplicas, *foo.Spec.Replicas, desiredReplicas, *deployment.Spec.Replicas)deployment, err c.kubeclientset.AppsV1().Deployments(foo.Namespace).Update(context.TODO(), newDeployment(foo), metav1.UpdateOptions{})}// If an error occurs during Update, well requeue the item so we can// attempt processing again later. This could have been caused by a// temporary network failure, or any other transient reason.if err ! nil {return err}// Finally, we update the status block of the Foo resource to reflect the// current state of the worlderr c.updateFooStatus(foo, deployment)if err ! nil {return err}c.recorder.Event(foo, corev1.EventTypeNormal, SuccessSynced, MessageResourceSynced)return nil
}
