Operator 示例：使用 Redis 部署 PHP 留言板應用程式-有解無憂

「Kubernetes 官方示例：使用 Redis 部署 PHP 留言板應用程式」Operator 化，

原始碼倉庫：https://github.com/jxlwqq/guestbook-operator

前置條件

安裝 Docker Desktop，并啟動內置的 Kubernetes 集群
注冊一個 hub.docker.com 賬戶，需要將本地構建好的鏡像推送至公開倉庫中
安裝 operator SDK CLI: brew install operator-sdk
安裝 Go: brew install go

本示例推薦的依賴版本：

Docker Desktop: >= 4.0.0
Kubernetes: >= 1.21.4
Operator-SDK: >= 1.11.0
Go: >= 1.17

jxlwqq 為筆者的 ID，命令列和代碼中涉及的個人 ID，均需要替換為讀者自己的，包括

--domain=

--repo=

//+kubebuilder:rbac:groups=

IMAGE_TAG_BASE ?=

創建專案

使用 Operator SDK CLI 創建名為 guestbook-operator 的專案，

mkdir -p $HOME/projects/guestbook-operator
cd $HOME/projects/guestbook-operator
go env -w GOPROXY=https://goproxy.cn,direct
```shell

operator-sdk init \
--domain=jxlwqq.github.io \
--repo=github.com/jxlwqq/guestbook-operator \
--skip-go-version-check

創建 API 和控制器

使用 Operator SDK CLI 創建自定義資源定義（CRD）API 和控制器，

運行以下命令創建帶有組 app、版本 v1alpha1 和種類 Guestbook 的 API：

operator-sdk create api \
--resource=true \
--controller=true \
--group=app \
--version=v1alpha1 \
--kind=Guestbook

定義 Guestbook 自定義資源（CR）的 API，

修改 api/v1alpha1/guestbook_types.go 中的 Go 型別定義，使其具有以下 spec 和 status

type GuestbookSpec struct {
	FrontendSize int32 `json:"frontendSize"`
	RedisFollowerSize int32 `json:"redisFollowerSize"`
}

為資源型別更新生成的代碼：

make generate

運行以下命令以生成和更新 CRD 清單：

make manifests

實作控制器

由于邏輯較為復雜，代碼較為龐大，所以無法在此全部展示，完整的操作器代碼請參見 controllers 目錄，
在本例中，將生成的控制器檔案 controllers/guestbook_controller.go 替換為以下示例實作：

/*
Copyright 2021.

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 at

    http://www.apache.org/licenses/LICENSE-2.0

Unless 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 controllers

import (
	"context"
	appsv1 "k8s.io/api/apps/v1"
	corev1 "k8s.io/api/core/v1"
	"k8s.io/apimachinery/pkg/api/errors"

	"k8s.io/apimachinery/pkg/runtime"
	ctrl "sigs.k8s.io/controller-runtime"
	"sigs.k8s.io/controller-runtime/pkg/client"
	"sigs.k8s.io/controller-runtime/pkg/log"

	appv1alpha1 "github.com/jxlwqq/guestbook-operator/api/v1alpha1"
)

// GuestbookReconciler reconciles a Guestbook object
type GuestbookReconciler struct {
	client.Client
	Scheme *runtime.Scheme
}

//+kubebuilder:rbac:groups=app.jxlwqq.github.io,resources=guestbooks,verbs=get;list;watch;create;update;patch;delete
//+kubebuilder:rbac:groups=app.jxlwqq.github.io,resources=guestbooks/status,verbs=get;update;patch
//+kubebuilder:rbac:groups=app.jxlwqq.github.io,resources=guestbooks/finalizers,verbs=update
//+kubebuilder:rbac:groups=apps,resources=deployments,verbs=get;list;watch;create;update;patch;delete
//+kubebuilder:rbac:groups=core,resources=service,verbs=get;list;watch;create;update;patch;delete
//+kubebuilder:rbac:groups=core,resources=pods,verbs=get;list;watch

// 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/[email protected]/pkg/reconcile
func (r *GuestbookReconciler) Reconcile(ctx context.Context, req ctrl.Request) (ctrl.Result, error) {
	reqLogger := log.FromContext(ctx)
	reqLogger.Info("Reconciling Guestbook")

	guestbook := &appv1alpha1.Guestbook{}
	err := r.Client.Get(context.TODO(), req.NamespacedName, guestbook)
	if err != nil {
		if errors.IsNotFound(err) {
			return ctrl.Result{}, nil
		}
		return ctrl.Result{}, err
	}

	var result = &ctrl.Result{}

	result, err = r.ensureDeployment(r.redisLeaderDeployment(guestbook))
	if result != nil {
		return *result, err
	}
	result, err = r.ensureService(r.redisLeaderService(guestbook))
	if result != nil {
		return *result, err
	}

	result, err = r.ensureDeployment(r.redisFollowerDeployment(guestbook))
	if result != nil {
		return *result, err
	}
	result, err = r.ensureService(r.redisFollowerService(guestbook))
	if result != nil {
		return *result, err
	}
	result, err = r.handleRedisFollowerChanges(guestbook)
	if result != nil {
		return *result, err
	}

	result, err = r.ensureDeployment(r.frontendDeployment(guestbook))
	if result != nil {
		return *result, err
	}
	result, err = r.ensureService(r.frontendService(guestbook))
	if result != nil {
		return *result, err
	}
	result, err = r.handleFrontendChanges(guestbook)
	if result != nil {
		return *result, err
	}

	return ctrl.Result{}, nil
}

// SetupWithManager sets up the controller with the Manager.
func (r *GuestbookReconciler) SetupWithManager(mgr ctrl.Manager) error {
	return ctrl.NewControllerManagedBy(mgr).
		For(&appv1alpha1.Guestbook{}).
		Owns(&appsv1.Deployment{}).
		Owns(&corev1.Service{}).
		Complete(r)
}

運行以下命令以生成和更新 CRD 清單：

make manifests

運行 Operator

捆綁 Operator，并使用 Operator Lifecycle Manager（OLM）在集群中部署，

修改 Makefile 中 IMAGE_TAG_BASE 和 IMG：

IMAGE_TAG_BASE ?= docker.io/jxlwqq/guestbook-operator
IMG ?= $(IMAGE_TAG_BASE):latest

構建鏡像：

make docker-build

將鏡像推送到鏡像倉庫：

make docker-push

成功后訪問：https://hub.docker.com/r/jxlwqq/guestbook-operator

運行 make bundle 命令創建 Operator 捆綁包清單，并依次填入名稱、作者等必要資訊:

make bundle

構建捆綁包鏡像：

make bundle-build

推送捆綁包鏡像：

make bundle-push

成功后訪問：https://hub.docker.com/r/jxlwqq/guestbook-operator-bundle

使用 Operator Lifecycle Manager 部署 Operator:

# 切換至本地集群
kubectl config use-context docker-desktop
# 安裝 olm
operator-sdk olm install
# 使用 Operator SDK 中的 OLM 集成在集群中運行 Operator
operator-sdk run bundle docker.io/jxlwqq/guestbook-operator-bundle:v0.0.1

創建自定義資源

編輯 config/samples/app_v1alpha1_guestbook.yaml 上的 Guestbook CR 清單示例，使其包含以下規格：

apiVersion: app.jxlwqq.github.io/v1alpha1
kind: Guestbook
metadata:
  name: guestbook-sample
spec:
  # Add fields here
  frontendSize: 2
  redisFollowerSize: 2

創建 CR：

kubectl apply -f config/samples/app_v1alpha1_guestbook.yaml

查看 Pod：

NAME                              READY   STATUS    RESTARTS   AGE
frontend-85595f5bf9-jrcp4         1/1     Running   0          9s
frontend-85595f5bf9-q8fkl         1/1     Running   0          9s
redis-follower-76c5cc5b79-fxxlq   1/1     Running   0          9s
redis-follower-76c5cc5b79-g8vnf   1/1     Running   0          9s
redis-leader-6666df964-vjhp2      1/1     Running   0          9s

查看 Service：

NAME             TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)        AGE
frontend         NodePort    10.106.145.169   <none>        80:30693/TCP   24s
kubernetes       ClusterIP   10.96.0.1        <none>        443/TCP        4m58s
redis-follower   ClusterIP   10.108.30.112    <none>        6379/TCP       24s
redis-leader     ClusterIP   10.106.255.152   <none>        6379/TCP       24s

瀏覽器訪問：http://localhost:30693

網頁上會顯示出 Guestbook 的表單頁面，

更新 CR：

# 修改frontend 和 redis 副本數
kubectl patch guestbook guestbook-sample -p '{"spec":{"frontendSize": 3, "redisFollowerSize": 3}}' --type=merge

查看 Pod：

NAME                              READY   STATUS    RESTARTS   AGE
frontend-85595f5bf9-4pmfj         1/1     Running   0          4s
frontend-85595f5bf9-jrcp4         1/1     Running   0          50s
frontend-85595f5bf9-q8fkl         1/1     Running   0          50s
redis-follower-76c5cc5b79-bxbb4   1/1     Running   0          4s
redis-follower-76c5cc5b79-fxxlq   1/1     Running   0          50s
redis-follower-76c5cc5b79-g8vnf   1/1     Running   0          50s
redis-leader-6666df964-vjhp2      1/1     Running   0          50s

做好清理

operator-sdk cleanup guestbook-operator
operator-sdk olm uninstall

更多經典示例請參考：https://github.com/jxlwqq/kubernetes-examples

轉載請註明出處，本文鏈接：https://www.uj5u.com/houduan/299855.html

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