Operator开发实例

开发环境搭建

    1.k8s集群

    2.Golang语言环境

   3.dep工具 Operator SDK是使用的dep工具包(Go语言的依赖管理工具包)
      curl https://raw.githubusercontent.com/golang/dep/master/install.sh | sh

     

   4.安装operator-sdk

      git clone https://github.com/operator-framework/operator-sdk

     cd   operator-sdk
     git   checkout   master
     make  tidy

    

     make  install

    

 operator-sdk cli安装调试

     执行make install命令会把生成的operator-sdk二进制可执行文件存放到GOPATH/bin目录下

 operator-sdk cli安装完毕,接下来搭建项目的脚手架

     1.cd /root/gopath/src/github.com/yxh  &&   /root/gopath/bin/operator-sdk new opdemo

       

     

    2.添加API 在项目的根目录下执行  cd  /root/gopath/src/github.com/yxh/opdemo

        /root/gopath/bin/operator-sdk add api --api-version=app.example.com/v1 --kind=AppService

    3.添加控制器

       /root/gopath/bin/operator-sdk add controller --api-version=app.example.com/v1 --kind=AppService

    

    4.整个Operator项目的脚手架就已经搭建完成

       我们主要需要编写的是pkg目录下面的api定义以及对应的controller实现

package appservice

import (
    "context"
    "encoding/json"
    "reflect"
    "fmt"
    "strconv"

    appv1 "github.com/yxh/opdemo/pkg/apis/app/v1"
    "github.com/yxh/opdemo/pkg/resources"
    appsv1 "k8s.io/api/apps/v1"
    corev1 "k8s.io/api/core/v1"
    "k8s.io/apimachinery/pkg/api/errors"
    "k8s.io/apimachinery/pkg/runtime"
    "sigs.k8s.io/controller-runtime/pkg/client"
    "sigs.k8s.io/controller-runtime/pkg/controller"
    "sigs.k8s.io/controller-runtime/pkg/handler"
    "sigs.k8s.io/controller-runtime/pkg/manager"
    "sigs.k8s.io/controller-runtime/pkg/reconcile"
    logf "sigs.k8s.io/controller-runtime/pkg/runtime/log"
    "sigs.k8s.io/controller-runtime/pkg/source"
)

var log = logf.Log.WithName("controller_appservice")

/**
* USER ACTION REQUIRED: This is a scaffold file intended for the user to modify with their own Controller
* business logic.  Delete these comments after modifying this file.*
 */

// Add creates a new AppService Controller and adds it to the Manager. The Manager will set fields on the Controller
// and Start it when the Manager is Started.
func Add(mgr manager.Manager) error {
    return add(mgr, newReconciler(mgr))
}

// newReconciler returns a new reconcile.Reconciler
func newReconciler(mgr manager.Manager) reconcile.Reconciler {
    return &ReconcileAppService{client: mgr.GetClient(), scheme: mgr.GetScheme()}
}

// add adds a new Controller to mgr with r as the reconcile.Reconciler
func add(mgr manager.Manager, r reconcile.Reconciler) error {
    // Create a new controller
    c, err := controller.New("appservice-controller", mgr, controller.Options{Reconciler: r})
    if err != nil {
        return err
    }

    // Watch for changes to primary resource AppService
    err = c.Watch(&source.Kind{Type: &appv1.AppService{}}, &handler.EnqueueRequestForObject{})
    if err != nil {
        return err
    }

    // TODO(user): Modify this to be the types you create that are owned by the primary resource
    // Watch for changes to secondary resource Pods and requeue the owner AppService
    err = c.Watch(&source.Kind{Type: &appsv1.Deployment{}}, &handler.EnqueueRequestForOwner{
        IsController: true,
        OwnerType:    &appv1.AppService{},
    })
    if err != nil {
        return err
    }

    return nil
}

var _ reconcile.Reconciler = &ReconcileAppService{}

// ReconcileAppService reconciles a AppService object
type ReconcileAppService struct {
    // This client, initialized using mgr.Client() above, is a split client
    // that reads objects from the cache and writes to the apiserver
    client client.Client
    scheme *runtime.Scheme
}

// Reconcile reads that state of the cluster for a AppService object and makes changes based on the state read
// and what is in the AppService.Spec
// TODO(user): Modify this Reconcile function to implement your Controller logic.  This example creates
// a Pod as an example
// Note:
// The Controller will requeue the Request to be processed again if the returned error is non-nil or
// Result.Requeue is true, otherwise upon completion it will remove the work from the queue.
func (r *ReconcileAppService) Reconcile(request reconcile.Request) (reconcile.Result, error) {
    reqLogger := log.WithValues("Request.Namespace", request.Namespace, "Request.Name", request.Name)
    reqLogger.Info("开始新的循环处理周期......")
    defer func(){
       reqLogger.Info("循环周期的最后执行步骤defer函数.....")
    }()


    // Fetch the AppService instance
    instance := &appv1.AppService{}
    reqLogger.Info("开始获取AppService资源.....")
    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.
        reqLogger.Info("获取AppService资源异常....")
        return reconcile.Result{}, err
    }
    reqLogger.Info("结束获取AppService资源.....")
    
    if instance.DeletionTimestamp != nil {
        return reconcile.Result{}, err
    }

    // 如果不存在，则创建关联资源
    // 如果存在，判断是否需要更新
    //   如果需要更新，则直接更新
    //   如果不需要更新，则正常返回
    reqLogger.Info("开始获取deployment资源.....")
    deploy := &appsv1.Deployment{}
    if err := r.client.Get(context.TODO(), request.NamespacedName, deploy); err != nil && errors.IsNotFound(err) {
        // 创建关联资源
        // 1. 创建 Deploy
        deploy := resources.NewDeploy(instance)
        if err := r.client.Create(context.TODO(), deploy); err != nil {
            return reconcile.Result{}, err
        }
        // 2. 创建 Service
        service := resources.NewService(instance)
        if err := r.client.Create(context.TODO(), service); err != nil {
            return reconcile.Result{}, err
        }
        // 3. 关联 Annotations
        //把instance.Spec的json对象中的数据转换成json字符串
        data, _ := json.Marshal(instance.Spec)

        //reqLogger.Info(string(instance.Spec))
        //reqLogger.Info(string(data))

        if instance.Annotations != nil {
            instance.Annotations["spec"] = string(data)
        } else {
            instance.Annotations = map[string]string{"spec": string(data)}
        }

        if err := r.client.Update(context.TODO(), instance); err != nil {
            return reconcile.Result{}, nil
        }
        return reconcile.Result{}, nil
    }
    reqLogger.Info("结束获取deployment资源.....")


    oldspec := appv1.AppServiceSpec{}
    reqLogger.Info("获取AppService的spec对象")

    //根据kubectl describe Appservice 查看annotations.spec为空
    //这里instance.Annotations["spec"]的值为nil
    //所以这里出错是因为添加Appservice对象的时候赋值的时候有问题

    // if {} == (instance.Annotations["spec"]) {
    //     reqLogger.Info("instance.Annotations为空。。。")
    // } else {
    //    reqLogger.Info("instance.Annotations不为空。。。。")
    // }
    // reqLogger.Info('instance.Annotations["spec"]的类型:%T',instance.Annotations["spec"])
    fmt.Println("instance.Annotations[\"spec\"]的类型:", reflect.TypeOf(instance.Annotations["spec"]))
    specstr := strconv.Quote(instance.Annotations["spec"])
    fmt.Println("instance.Annotations[\"spec\"]的内容:",specstr)

    //将json字符串解码到相应的数据结构appv1.AppServiceSpec
    if err := json.Unmarshal([]byte(instance.Annotations["spec"]), &oldspec); err != nil {
        return reconcile.Result{}, err
    }

    if !reflect.DeepEqual(instance.Spec, oldspec) {
        // 更新关联资源
        newDeploy := resources.NewDeploy(instance)
        oldDeploy := &appsv1.Deployment{}
        if err := r.client.Get(context.TODO(), request.NamespacedName, oldDeploy); err != nil {
            return reconcile.Result{}, err
        }
        oldDeploy.Spec = newDeploy.Spec
        if err := r.client.Update(context.TODO(), oldDeploy); err != nil {
            return reconcile.Result{}, err
        }

        newService := resources.NewService(instance)
        oldService := &corev1.Service{}

        if err := r.client.Get(context.TODO(), request.NamespacedName, oldService); err != nil {
            return reconcile.Result{}, err
        }

        // oldService.Spec = newService.Spec
        // reqLogger.Info("到这里了........")
        fmt.Print(oldService.Spec)

        //client.Update service会出错
        //Service nginx-app-5 is invalid: spec.clusterIP: Invalid value: \"\": field is immutable"
        // if err := r.client.Update(context.TODO(), oldService); err != nil {
        //     return reconcile.Result{}, err
        // }

        //先删除原来的service
         if err := r.client.Delete(context.TODO(), oldService); err != nil {
            return reconcile.Result{}, err
        } else {
            reqLogger.Info("删除原来的service的了......")
        }

        //创建一个新的service
        if err := r.client.Create(context.TODO(), newService); err != nil {
            return reconcile.Result{}, err
        } else {
            reqLogger.Info("创建新的service......")
        }
        return reconcile.Result{}, nil
    }
    return reconcile.Result{}, nil
}

controller.go