# 1-BeginStudy **Repository Path**: demin520/study1 ## Basic Information - **Project Name**: 1-BeginStudy - **Description**: Kubernetes Operator 快速入门教程 - **Primary Language**: Go - **License**: Not specified - **Default Branch**: master - **Homepage**: None - **GVP Project**: No ## Statistics - **Stars**: 0 - **Forks**: 1 - **Created**: 2023-03-17 - **Last Updated**: 2023-03-17 ## Categories & Tags **Categories**: Uncategorized **Tags**: None ## README # Kubernetes Operator 快速入门教程 个人介绍 方玉龙 湖北大学 大三学弟 兴趣k8s 欢迎交流 联系方式 qq 3095329264 邮箱 3095329264@qq.com ## 环境需求 Go 语言的依赖管理工具包：[dep](https://github.com/golang/dep) operator-sdk operator sdk 安装方法非常多，我们可以直接在 github 上面下载需要使用的版本，然后放置到 PATH 环境下面即可，当然也可以将源码 clone 到本地手动编译安装即可，如果你是 Mac，当然还可以使用常用的 brew 工具进行安装： ```powershell $ brew install operator-sdk ...... $ operator-sdk version operator-sdk version: v0.7.0 $ go version go version go1.11.4 darwin/amd64 ``` ## 开始创建 ### 创建新项目 operator-sdk new imoocpod-operator --skip-validation=true --repo=github.com/imooc-com/imooc/imoocpod-operator ```shell operator-sdk new opdemo ``` ```shell INFO[0000] Creating new Go operator 'opdemo'. INFO[0000] Created go.mod INFO[0000] Created tools.go INFO[0000] Created cmd/manager/main.go INFO[0000] Created build/Dockerfile INFO[0000] Created build/bin/entrypoint INFO[0000] Created build/bin/user_setup INFO[0000] Created deploy/service_account.yaml INFO[0000] Created deploy/role.yaml INFO[0000] Created deploy/role_binding.yaml INFO[0000] Created deploy/operator.yaml INFO[0000] Created pkg/apis/apis.go INFO[0000] Created pkg/controller/controller.go INFO[0000] Created version/version.go INFO[0000] Created .gitignore INFO[0000] Validating project INFO[0031] Project validation successful. INFO[0031] Project creation complete. ``` ```shell cd opdemo && tree -L 2 ``` ```shell . ├── Gopkg.lock ├── Gopkg.toml ├── build │ ├── Dockerfile │ ├── _output │ └── bin ├── cmd │ └── manager ├── deploy │ ├── crds │ ├── operator.yaml │ ├── role.yaml │ ├── role_binding.yaml │ └── service_account.yaml ├── pkg │ ├── apis │ └── controller ├── vendor │ ├── cloud.google.com │ ├── contrib.go.opencensus.io │ ├── github.com │ ├── go.opencensus.io │ ├── go.uber.org │ ├── golang.org │ ├── google.golang.org │ ├── gopkg.in │ ├── k8s.io │ └── sigs.k8s.io └── version └── version.go 23 directories, 8 files ``` - **Gopkg.toml Gopkg.lock** — Go Dep 清单，用来描述当前 Operator 的依赖包。 - **cmd** - 包含 main.go 文件，使用 operator-sdk API 初始化和启动当前 Operator 的入口。 - **deploy** - 包含一组用于在 Kubernetes 集群上进行部署的通用的 Kubernetes 资源清单文件。 - **pkg/apis** - 包含定义的 API 和自定义资源（CRD）的目录树，这些文件允许 sdk 为 CRD 生成代码并注册对应的类型，以便正确解码自定义资源对象。 - **pkg/controller** - 用于编写所有的操作业务逻辑的地方 - **vendor** - golang vendor 文件夹，其中包含满足当前项目的所有外部依赖包，通过 go dep 管理该目录。 ### 添加API operator-sdk add api --api-version=k8s.imooc.com/v1alpha1 --kind=ImoocPod ```shell operator-sdk add api --api-version=app.example.com/v1 --kind=AppService ``` ```powershell INFO[0000] Generating api version app.example.com/v1 for kind AppService. INFO[0000] Created pkg/apis/app/group.go INFO[0031] Created pkg/apis/app/v1/appservice_types.go INFO[0062] Created pkg/apis/addtoscheme_app_v1.go INFO[0062] Created pkg/apis/app/v1/register.go INFO[0062] Created pkg/apis/app/v1/doc.go INFO[0062] Created deploy/crds/app.example.com_v1_appservice_cr.yaml INFO[0062] Running deepcopy code-generation for Custom Resource group versions: [app:[v1], ] INFO[0079] Code-generation complete. INFO[0079] Running CRD generator. INFO[0080] CRD generation complete. INFO[0080] API generation complete. INFO[0080] API generation complete. ``` pkg/apis 下多出app文件夹 deploy 下多出crds文件夹 ### 添加控制器 operator-sdk add controller --api-version=k8s.imcco.com/v1alpha1 --kind=ImoocPod ```shell operator-sdk add controller --api-version=app.example.com/v1 --kind=AppService ``` 多出pkg/controller/appservice/appservice_controller.go 多出pkg/controller/add_appservice.go ### 部署文件 operator-sdk build mock.com:5000/imoocpod-operator docker push mock.com:5000/imoocpod-operator kubectl apply -f deploy/service_account.yaml kubectl apply -f deploy/role.yaml kubectl apply -f deploy/role_binding.yaml kubectl apply -f deploy/crds/k8s.imooc.com_imoocpods_crd.yaml 替换operator.yaml 中的image kubectl apply -f deploy/operator.yaml kubectl apply -f deploy/crds/k8s.imooc.com_v1alpha1_imoocpod_cr.yaml ### 自定义字段 apis/v1alpha1/types.go ```go type ImoocPodSpec struct { Replicas int `json:"replicas"` } type ImoocPodStatus struct { Replicas int `json:"replicas"` PodNames []string `json:"podNames"` } ``` operator-sdk generate k8s operator-sdk generate crds ### 自定义控制器 Controller.go ```go func (r *ReconcileImoocPod) Reconcile(request reconcile.Request) (reconcile.Result, error) { reqLogger := log.WithValues("Request.Namespace", request.Namespace, "Request.Name", request.Name) reqLogger.Info("Reconciling ImoocPod") // Fetch the ImoocPod instance instance := &k8sv1alpha1.ImoocPod{} err := r.client.Get(context.TODO(), request.NamespacedName, instance) if err != nil { if errors.IsNotFound(err) { // Request object not found, could have been deleted after reconcile request. // Owned objects are automatically garbage collected. For additional cleanup logic use finalizers. // Return and don't requeue return reconcile.Result{}, nil } // Error reading the object - requeue the request. return reconcile.Result{}, err } //1 获取name对应的所有pod lbls := labels.Set{ "app":instance.Name,//资源的label 来查找对应的pod } existringPods := &corev1.PodList{} err = r.client.List(context.TODO(),existringPods,&client.ListOptions{ Namespace: request.Namespace, LabelSelector: labels.SelectorFromSet(lbls), }) if err != nil{ reqLogger.Error(err,"取已经存在的pod失败") return reconcile.Result{},err } //2 获取pod列表中的所有pod name var existringPodNames []string for _,pod := range existringPods.Items{ //如果删除时间戳不为0 则跳过添加操作 if pod.GetObjectMeta().GetDeletionTimestamp() != nil{ continue } if pod.Status.Phase == corev1.PodPending || pod.Status.Phase == corev1.PodRunning{ existringPodNames = append(existringPodNames,pod.GetObjectMeta().GetName()) } } //3 :update pod.status == 运行中的status // 比较DeepEqual status := k8sv1alpha1.ImoocPodStatus{ PodNames: existringPodNames, Replicas: len(existringPodNames), } if !reflect.DeepEqual(instance.Status,status){ instance.Status = status //把期望状态给运行状态 err := r.client.Status().Update(context.TODO(),instance) if err!= nil{ reqLogger.Error(err,"更新pod失败") } } //4 len(pod) > 运行中的len(pod.replices) 期望值小 需要scale down if len(existringPodNames) > instance.Spec.Replicas{ //delete reqLogger.Info("正在删除pod，当前的existringPodNames和期望的replicas",existringPodNames,instance.Spec.Replicas) pod := existringPods.Items[0] err := r.client.Delete(context.TODO(),&pod) if err != nil{ reqLogger.Error(err,"删除pod失败") return reconcile.Result{},err } } //5 len(pod) < 运行中的len(pod.replices) 期望值大，需要scale up create if len(existringPodNames) < instance.Spec.Replicas{ reqLogger.Info("正在删除pod，当前的existringPodNames和期望的replicas",existringPodNames,instance.Spec.Replicas) // Define a new Pod object pod := newPodForCR(instance) // Set ImoocPod instance as the owner and controller if err := controllerutil.SetControllerReference(instance, pod, r.scheme); err != nil { return reconcile.Result{}, err } err = r.client.Create(context.TODO(),pod) if err != nil{ reqLogger.Error(err,"创建pod失败") return reconcile.Result{}, err } } return reconcile.Result{Requeue: true},nil } ``` ```go func newPodForCR(cr *k8sv1alpha1.ImoocPod) *corev1.Pod { labels := map[string]string{ "app": cr.Name, } return &corev1.Pod{ ObjectMeta: metav1.ObjectMeta{ GenerateName: cr.Name + "-pod", Namespace: cr.Namespace, Labels: labels, }, Spec: corev1.PodSpec{ Containers: []corev1.Container{ { Name: "busybox", Image: "busybox", Command: []string{"sleep", "3600"}, }, }, }, } } ``` operator-sdk generate k8s ### 重新部署 operator-sdk build mock.com:5000/imoocpod-operator docker push mock.com:5000/imoocpod-operator 删除cr 和crd文件operator文件 重新部署 ```shell fangyulong@BDSZYF000146577 imoocpod-operator % kubectl get pod NAME READY STATUS RESTARTS AGE example-imoocpod-pod2ghzt 1/1 Running 0 63s example-imoocpod-pod6fwc5 1/1 Running 0 63s example-imoocpod-pods7wbp 1/1 Running 0 63s imoocpod-operator-7959bdcb7d-f9hgf 1/1 Running 0 69s ``` ###