权重高的博客网站,做网站找外包好吗,做网站首页文字排版技巧,颖灵信息科技网站建设K8s CRD 即 Kubernetes CustomResourceDefinition#xff0c;是 Kubernetes 提供的一种扩展机制#xff0c;允许用户在 Kubernetes 集群中定义和使用自定义的资源类型。通过定义 CRD#xff0c;用户可以在 Kubernetes 集群中创建、读取、更新和删除自定义资源对象#xff0…K8s CRD 即 Kubernetes CustomResourceDefinition是 Kubernetes 提供的一种扩展机制允许用户在 Kubernetes 集群中定义和使用自定义的资源类型。通过定义 CRD用户可以在 Kubernetes 集群中创建、读取、更新和删除自定义资源对象就像使用原生的 Pod、Service 等资源一样。
本文主要介绍如何使用kubebuilder快速创建自定义资源类型。完成guestbook资源类型自定义并通过CRD Controller创建deloyment对象通过deployment运行管理pod
前提条件
安装go https://go.dev/doc/install安装k8s可查看上一篇文章
安装kubebuilder
参考文档步骤https://book.kubebuilder.io/quick-start
# download kubebuilder and install locally.
curl -L -o kubebuilder https://go.kubebuilder.io/dl/latest/$(go env GOOS)/$(go env GOARCH)
chmod x kubebuilder sudo mv kubebuilder /usr/local/bin/
创建CRD
创建Project CRD API
mkdir -p ~/projects/guestbook
cd ~/projects/guestbook
kubebuilder init --domain my.domain --repo my.domain/guestbook
kubebuilder create api --group webapp --version v1 --kind Guestbook执行完上面两个命令之后会初始化一个k8s控制器项目并且创建自定义资源及相关代码。
安装CRD
执行make manifests生成资源配置文件
[rootmaster guestbook]# make manifests
/root/crd/guestbook/bin/controller-gen rbac:roleNamemanager-role crd webhook paths./... output:crd:artifacts:configconfig/crd/bases
根据需要编辑api/v1/guestbook_types.go文件 // GuestbookSpec defines the desired state of Guestbook.
type GuestbookSpec struct {// INSERT ADDITIONAL SPEC FIELDS - desired state of cluster// Important: Run make to regenerate code after modifying this file// Foo is an example field of Guestbook. Edit guestbook_types.go to remove/updateFoo string json:foo,omitemptyReplicas int32 json:replicas,omitemptyImage string json:image,omitempty
}// GuestbookStatus defines the observed state of Guestbook.
type GuestbookStatus struct {// INSERT ADDITIONAL STATUS FIELD - define observed state of cluster// Important: Run make to regenerate code after modifying this fileServiceStatus string json:serviceStatusReplicas int32 json:replicas,omitempty
}
编写CRD Controller代码internal/controller/guestbook_controller.go 前面只是定义了guestbook的资源类型当创建guestbook类型时需要做什么操作是通过CRD Controller来完成的 本示例用controller创建一个deployment类型的资源运行两个Nginx Pod。
kubebuilder已经帮我们生成了代码框架guestbook_controller.go只需要在Reconcile方法添加相关的逻辑即可。
/*
Copyright 2025.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 athttp://www.apache.org/licenses/LICENSE-2.0Unless 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 controllerimport (contextfmtk8s.io/apimachinery/pkg/api/errorsk8s.io/apimachinery/pkg/runtimectrl sigs.k8s.io/controller-runtimesigs.k8s.io/controller-runtime/pkg/clientsigs.k8s.io/controller-runtime/pkg/logcorev1 k8s.io/api/core/v1appsv1 k8s.io/api/apps/v1webappv1 my.domain/guestbook/api/v1metav1 k8s.io/apimachinery/pkg/apis/meta/v1
)// GuestbookReconciler reconciles a Guestbook object
type GuestbookReconciler struct {client.ClientScheme *runtime.Scheme
}// kubebuilder:rbac:groupswebapp.my.domain,resourcesguestbooks,verbsget;list;watch;create;update;patch;delete
// kubebuilder:rbac:groupswebapp.my.domain,resourcesguestbooks/status,verbsget;update;patch
// kubebuilder:rbac:groupswebapp.my.domain,resourcesguestbooks/finalizers,verbsupdate// Reconcile is part of the main kubernetes reconciliation loop which aims to
// move the current state of the cluster closer to the desired state.
// TODO(user): Modify the Reconcile function to compare the state specified by
// the Guestbook object against the actual cluster state, and then
// perform operations to make the cluster state reflect the state specified by
// the user.
//
// For more details, check Reconcile and its Result here:
// - https://pkg.go.dev/sigs.k8s.io/controller-runtimev0.19.1/pkg/reconcile//资源对象创建/更新/删除/变化时触发调用
func (r *GuestbookReconciler) Reconcile(ctx context.Context, req ctrl.Request) (ctrl.Result, error) {logger : log.FromContext(ctx)fmt.Printf(Guestbook Reconcile called....%v...%v \n,req.Name,req.Namespace)// 获取当前已存在的Deployment对象如果有的话existingDeployment : appsv1.Deployment{}err1 : r.Get(ctx, client.ObjectKey{Namespace: req.Namespace,Name: fmt.Sprintf(%s-deployment, req.Name),}, existingDeployment)var guestbook webappv1.Guestbookif err : r.Get(ctx, req.NamespacedName, guestbook); err ! nil {//如果guestbook资源不存在删除已有的deploymentif errors.IsNotFound(err) {return r.handleGuestbookDeleted(existingDeployment,ctx,req)}}desiredDeployment : r.buildDeploymentForGuestbook(guestbook,req)if err1!nil errors.IsNotFound(err1) {// 如果不存在则创建Deploymentif err : r.Create(ctx, desiredDeployment); err ! nil {return ctrl.Result{}, fmt.Errorf(failed to create Deployment: %v, err)}logger.Info(Deployment created successfully)} else {// 对比期望的Deployment和已存在的Deployment若有差异则更新if !r.deploymentsEqual(desiredDeployment, existingDeployment) {existingDeployment.Spec desiredDeployment.Specif err : r.Update(ctx, existingDeployment); err ! nil {return ctrl.Result{}, fmt.Errorf(failed to update Deployment: %v, err)}logger.Info(Deployment updated successfully)}}// 更新Guestbook资源的状态这里简单示例可根据实际情况完善状态更新逻辑fmt.Printf(guestbook spec replicas: %v \n,guestbook.Spec.Replicas)guestbook.Status.Replicas guestbook.Spec.Replicasguestbook.Status.ServiceStatus Runningif err : r.Status().Update(ctx, guestbook); err ! nil {return ctrl.Result{}, fmt.Errorf(failed to update Guestbook status: %v, err)}return ctrl.Result{}, nil
}// handleGuestbookDeleted处理Guestbook资源被删除的情况删除对应的Deployment
func (r *GuestbookReconciler) handleGuestbookDeleted(existedDeployment *appsv1.Deployment,ctx context.Context, req ctrl.Request) (ctrl.Result, error) {if (existedDeployment ! nil existedDeployment.Name ! ) {err : r.Delete(ctx, existedDeployment)if err ! nil {log.FromContext(ctx).Error(err, failed to delete Deployment)return ctrl.Result{}, err}return ctrl.Result{}, nil}//logger : log.FromContext(ctx) 获取当前已存在的Deployment对象如果有的话//existingDeployment : appsv1.Deployment{}////err : r.Get(ctx, client.ObjectKey{// Namespace: req.Namespace,// Name: fmt.Sprintf(%s-deployment, req.Name),// Name: guestbook-sample-deployment,//}, existingDeployment)//logger.Error(err, handleGuestbookDeleted err is not null)// If GuestBook does not exist, remove the Deployment if it exists//if err nil {//// logger.Info(GuestBook resource not found, removing the associated Deployment)// err r.Delete(ctx, existingDeployment)// if err ! nil {// logger.Error(err, failed to delete Deployment)// return ctrl.Result{}, err// }// return ctrl.Result{}, nil//} else {// logger.Error(err, handleGuestbookDeleted err is not null)// //fmt.Println(handleGuestbookDeleted err is not null)//}return ctrl.Result{}, nil
}// buildDeploymentForGuestbook根据Guestbook资源构建期望的Deployment对象
func (r *GuestbookReconciler) buildDeploymentForGuestbook(guestbook *webappv1.Guestbook,req ctrl.Request) *appsv1.Deployment {labels : map[string]string{app: guestbook.Name,}replicas : guestbook.Spec.Replicasreturn appsv1.Deployment{ObjectMeta: metav1.ObjectMeta{Name: fmt.Sprintf(%s-deployment, req.Name),Namespace: req.Namespace,Labels: labels,},Spec: appsv1.DeploymentSpec{Replicas: replicas,Selector: metav1.LabelSelector{MatchLabels: labels,},Template: corev1.PodTemplateSpec{ObjectMeta: metav1.ObjectMeta{Labels: labels,},Spec: corev1.PodSpec{Containers: []corev1.Container{{Name: guestbook-container,Image: guestbook.Spec.Image,Ports: []corev1.ContainerPort{{Name: http,ContainerPort: 80,},},},},},},},}
}// deploymentsEqual比较两个Deployment对象是否相等简单比较主要属性
func (r *GuestbookReconciler) deploymentsEqual(d1, d2 *appsv1.Deployment) bool {return d1.Spec.Replicas d2.Spec.Replicas d1.Spec.Template.Spec.Containers[0].Image d2.Spec.Template.Spec.Containers[0].Image
}// SetupWithManager sets up the controller with the Manager.
func (r *GuestbookReconciler) SetupWithManager(mgr ctrl.Manager) error {return ctrl.NewControllerManagedBy(mgr).For(webappv1.Guestbook{}).Named(guestbook).Complete(r)
}执行make install安装命令
[rootmaster guestbook]# make install
/root/crd/guestbook/bin/controller-gen rbac:roleNamemanager-role crd webhook paths./... output:crd:artifacts:configconfig/crd/bases
/root/crd/guestbook/bin/kustomize build config/crd | kubectl apply -f -
customresourcedefinition.apiextensions.k8s.io/guestbooks.webapp.my.domain created
验证资源是否存在 执行 kubectl api-resources可以看到guestbooks资源已经被创建。
[rootmaster guestbook]# kubectl api-resources---前面省略---
priorityclasses pc scheduling.k8s.io/v1 false PriorityClass
csidrivers storage.k8s.io/v1 false CSIDriver
csinodes storage.k8s.io/v1 false CSINode
csistoragecapacities storage.k8s.io/v1 true CSIStorageCapacity
storageclasses sc storage.k8s.io/v1 false StorageClass
volumeattachments storage.k8s.io/v1 false VolumeAttachment
guestbooks webapp.my.domain/v1 true Guestbook
创建guestbook资源对象
先执行make run命令将前面创建的Controller运行起来
[rootmaster guestbook]# make run
/root/crd/guestbook/bin/controller-gen rbac:roleNamemanager-role crd webhook paths./... output:crd:artifacts:configconfig/crd/bases
/root/crd/guestbook/bin/controller-gen object:headerFilehack/boilerplate.go.txt paths./...
go fmt ./...
go vet ./...
go run ./cmd/main.go
2025-01-09T07:36:11-05:00 INFO setup starting manager
2025-01-09T07:36:11-05:00 INFO starting server {name: health probe, addr: [::]:8081}
2025-01-09T07:36:11-05:00 INFO Starting EventSource {controller: guestbook, controllerGroup: webapp.my.domain, controllerKind: Guestbook, source: kind source: *v1.Guestbook}
2025-01-09T07:36:11-05:00 INFO Starting Controller {controller: guestbook, controllerGroup: webapp.my.domain, controllerKind: Guestbook}
2025-01-09T07:36:11-05:00 INFO Starting workers {controller: guestbook, controllerGroup: webapp.my.domain, controllerKind: Guestbook, worker count: 1}
创建刚定义的CRD资源 kubebuilder已经生成了一个yaml文件样例 /config/samples/webapp_v1_guestbook.yaml
修改下相关参数
apiVersion: webapp.my.domain/v1
kind: Guestbook
metadata:labels:app.kubernetes.io/name: guestbookapp.kubernetes.io/managed-by: kustomizename: guestbook-sample
spec:replicas: 2image: nginx执行创建命令
[rootmaster guestbook]# kubectl apply -k config/samples
guestbook.webapp.my.domain/guestbook-sample created
# 验证是否创建成功
[rootmaster guestbook]# kubectl get guestbook
NAME AGE
guestbook-sample 17s
[rootmaster guestbook]# kubectl get deployment
NAME READY UP-TO-DATE AVAILABLE AGE
guestbook-sample-deployment 2/2 2 2 22s
tomcat-deployment 2/2 2 2 17d
wordpress 0/1 1 0 12d
# 两个Nginx Pod已经被创建
[rootmaster guestbook]# kubectl get pod
NAME READY STATUS RESTARTS AGE
guestbook-sample-deployment-654b67bc8f-kkpdr 1/1 Running 0 25s
guestbook-sample-deployment-654b67bc8f-sf6t5 1/1 Running 0 25s# 如果要查看guestbook更详细信息执行
kubectl get guestbook -o yaml如果需要删除 guestbook资源类型可以执行
kubectl delete -k config/samples
