使用 kubebuilder 创建并部署 k8s-operator

一、准备

本文中的示例运行环境及相关软件版本如下:

  • Kubernetes v1.16.3
  • Go 1.15.6
  • Kubebuilder 3.1.0
  • Docker 20.10.7

安装kubebuilder:

#下载kubebuilder 3.1.0,建议二进制版本:https://github.com/kubernetes-sigs/kubebuilder/releases
#将二进制文件copy到/usr/local/bin下 
% chmod +x kubebuilder && mv kubebuilder /usr/local/bin/
#验证 
% kubebuilder version

二、创建项目

% mkdir guestbook 
% cd guestbook %
% go mod init guestbook //go mod管理包 
% kubebuilder init --domain xiaohongshu.org --owner "luxiu"

三、创建API

% kubebuilder create api --group redis  --version v1 --kind RedisCluster
Create Resource [y/n]
y
Create Controller [y/n]
y
Writing kustomize manifests for you to edit...
Writing scaffold for you to edit...
api/v1/rediscluster_types.go
controllers/rediscluster_controller.go
Update dependencies:
$ go mod tidy
Running make:
$ make generate
go: creating new go.mod: module tmp
Downloading sigs.k8s.io/controller-tools/cmd/controller-gen@v0.4.1
go: found sigs.k8s.io/controller-tools/cmd/controller-gen in sigs.k8s.io/controller-tools v0.4.1
/Users/luxiu/Desktop/luxiu/project/kubernetes/crd-test/bin/controller-gen object:headerFile="hack/boilerplate.go.txt" paths="./..."

API 创建完成后,在项目根目录下查看目录结构:

四、安装 CRD

这里安装CRD到指定的k8s集群里,需要修改Makefile里连接k8s配置:

install: manifests kustomize ## Install CRDs into the K8s cluster specified in ~/.kube/config.
        $(KUSTOMIZE) build config/crd | kubectl --context cls-j07gq3ud-context-default  apply -f -
uninstall: manifests kustomize ## Uninstall CRDs from the K8s cluster specified in ~/.kube/config.
        $(KUSTOMIZE) build config/crd | kubectl --context cls-j07gq3ud-context-default  delete -f -
deploy: manifests kustomize ## Deploy controller to the K8s cluster specified in ~/.kube/config.
        cd config/manager && $(KUSTOMIZE) edit set image controller=${IMG}
        $(KUSTOMIZE) build config/default | kubectl --context cls-j07gq3ud-context-default apply -f -
undeploy: ## Undeploy controller from the K8s cluster specified in ~/.kube/config.
        $(KUSTOMIZE) build config/default | kubectl --context cls-j07gq3ud-context-default delete -f -

执行下面命令来安装CRD:

 % make install
/Users/luxiu/Desktop/luxiu/project/kubernetes/crd-test/bin/controller-gen "crd:trivialVersions=true,preserveUnknownFields=false" rbac:roleName=manager-role webhook paths="./..." output:crd:artifacts:config=config/crd/bases
/Users/luxiu/Desktop/luxiu/project/kubernetes/crd-test/bin/kustomize build config/crd | kubectl --context cls-j07gq3ud-context-default  apply -f -
customresourcedefinition.apiextensions.k8s.io/redisclusters.redis.xiaohongshu.org created

五、部署 Controller

在开始部署 controller 之前,我们需要先检查 kubebuilder 自动生成的 YAML 文件。

修改使用 gcr.io 镜像仓库的镜像地址

对于中国大陆用户,可能无法访问 Google 镜像仓库 gcr.io,因此需要修改 config/default/manager_auth_proxy_patch.yaml 文件中的镜像地址,将其中 gcr.io/kubebuilder/kube-rbac-proxy:v0.8.0 修改为quay.io/brancz/kube-rbac-proxy:v0.8.0

有两种方式运行 controller:

  • 本地运行,用于调试
  • 部署到 Kubernetes 上运行,作为生产使用

本地运行 controller

要想在本地运行 controller,只需要执行下面的命令,你将看到 controller 启动和运行时输出:

$ make run

将 Controller 部署到指定 Kubernetes集群

这里有个问题,需要修改Dockerfile中 ,给go 设置proxy代理,这样go mod download时不至于超时连不上:

在 RUN go mod download 这行的上面加如下一行:
ENV GOPROXY="https://goproxy.cn"

构建 controller 的镜像,并推送到公司docker harbor 上,然后在 Kubernetes 上部署 Deployment 资源,如下命令:

$ make docker-build  IMG=docker-reg.devops.xiaohongshu.com/data-infra/rediscluster:v1
$ make docker-push  IMG=docker-reg.devops.xiaohongshu.com/data-infra/rediscluster:v1
$ make deploy  IMG=docker-reg.devops.xiaohongshu.com/data-infra/rediscluster:v1

在初始化项目时,kubebuilder 会自动根据项目名称创建一个 Namespace,如本文中的guestbook-system ,查看 Deployment 对象和 Pod 资源。

% k8sdev get deployment -n guestbook-system
NAME                           READY   UP-TO-DATE   AVAILABLE   AGE
guestbook-controller-manager   1/1     1            1           25h
% k8sdev get pod  -n guestbook-system
NAME                                            READY   STATUS    RESTARTS   AGE
guestbook-controller-manager-79fd58d674-fvm2m   2/2     Running   0          145m

六、创建 CR

该创建自定义资源对象CR了,如原生中的rc/deployment等对象

% k8sdev apply -f config/samples/redis_v1_rediscluster.yaml
rediscluster.redis.xiaohongshu.org/rediscluster-sample created
% k8sdev get RedisCluster
NAME                  AGE
rediscluster-sample   38s

至此一个基本的 Operator 框架已经创建完成,但这个 Operator 只是修改了 etcd 中的数据而已,实际上什么事情也没做,因为我们没有在 Operator 中的增加业务逻辑。

七、开发业务逻辑

下面我们将修改 CRD 的数据结构并在 controller 中增加一些日志输出。

修改 CRD

我们将修改api/v1/guestbook_types.go 文件的内容,在 CRD 中增加 FirstNameLastName 和 Status 字段。

// 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/update
	FirstName string `json:"firstname"`
	LastName  string `json:"lastname"`
}

// 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 file
	Status string `json:"Status"`
}

修改 Reconcile 函数

Reconcile 函数是 Operator 的核心逻辑,Operator 的业务逻辑都位于 controllers/guestbook_controller.go 文件的 Reconcile 函数中

func (r *GuestbookReconciler) Reconcile(ctx context.Context, req ctrl.Request) (ctrl.Result, error) {
	_ = log.FromContext(ctx)

	// your logic here
	// 获取当前的 CR,并打印
	logger := log.FromContext(ctx)
	obj := &webappv1.Guestbook{}
	if err := r.Get(ctx, req.NamespacedName, obj); err != nil {
		logger.Error(err, "Unable to fetch object")
		return ctrl.Result{}, nil
	} else {
		logger.Info("Greeting from Kubebuilder to", obj.Spec.FirstName, obj.Spec.LastName)
	}

	// 初始化 CR 的 Status 为 Running
	obj.Status.Status = "Running"
	if err := r.Status().Update(ctx, obj); err != nil {
		logger.Error(err, "unable to update status")
	}

	return ctrl.Result{}, nil
}

运行测试

  • 安装CRD(同上)
  • 部署controller(同上)
  • 创建CR

 修改 config/samples/redis_v1_rediscluster.yaml 文件中的配置

apiVersion: redis.xiaohongshu.org/v1
kind: RedisCluster
metadata:
  name: rediscluster-sample
spec:
  # Add fields here
  firstname: Jimmy
  lastname: Song

执行下面命令,创建CR:

$ k8sdev apply -f  config/samples/redis_v1_rediscluster.yaml

查看controller里的运行日志:

% k8sdev get pod  -n guestbook-system
NAME                                            READY   STATUS    RESTARTS   AGE
guestbook-controller-manager-79fd58d674-fvm2m   2/2     Running   0          3h53m

% k8sdev logs -f guestbook-controller-manager-79fd58d674-fvm2m -n guestbook-system -c manager
2022-03-08T08:24:04.641Z	INFO	controller-runtime.manager.controller.guestbook	Greeting from Kubebuilder to	{"reconciler group": "webapp.my.domain", "reconciler kind": "Guestbook", "name": "guestbook-sample", "namespace": "default", "Jimmy": "Song"}
2022-03-08T08:24:04.651Z	INFO	controller-runtime.manager.controller.guestbook	Greeting from Kubebuilder to	{"reconciler group": "webapp.my.domain", "reconciler kind": "Guestbook", "name": "guestbook-sample", "namespace": "default", "Jimmy": "Song"}

 

 

参考:部署k8s operator

 

posted @ 2022-03-08 20:19  茁壮的小草  阅读(1641)  评论(0编辑  收藏  举报