k8s单机部署wordpress

在前文k8s部署有状态应用中，简单介绍了StatefulSet的使用。

• 《Kubectl 部署有状态应用（上）》
• 《Kubectl 部署有状态应用（下）》

本教程将展示如何使用 Minikube 部署 WordPress 站点和 MySQL 数据库。这两个应用程序都使用 PersistentVolumes 和 PersistentVolumeClaims 来存储数据。

PersistentVolume (PV) 是集群中的一块存储，由管理员手动配置，或者由 Kubernetes 使用 StorageClass动态配置。PersistentVolumeClaim (PVC )是用户提出的存储请求，可以通过 PV 来满足。PersistentVolumes 和 PersistentVolumeClaims 独立于 Pod 生命周期，并通过重新启动、重新调度甚至删除 Pod 来保留数据。

本文目标

• 创建pv和pvc
• 创建一个包含Secret generator 和mysql与wordpress配置的yaml文件
• 部署
• 清除

创建kustomization

Secret是存储密码或密钥等敏感数据的对象。从 1.14 开始，kubectl支持使用 kustomization 文件管理 Kubernetes 对象。

执行以下命令将Secret添加到kustomization.yaml。记得更换password

cat <<EOF >./kustomization.yaml
secretGenerator:
- name: mysql-pass
  literals:
  - password=YOUR_PASSWORD
EOF

创建MySQL yaml

vim mysql-deployment.yaml

MySQL 容器将 PersistentVolume 挂载在 /var/lib/mysql 处。环境MYSQL_ROOT_PASSWORD 变量设置来自 Secret 的数据库密码。

apiVersion: v1
kind: Service
metadata:
  name: wordpress-mysql
  labels:
    app: wordpress
spec:
  ports:
    - port: 3306
  selector:
    app: wordpress
    tier: mysql
  clusterIP: None
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: mysql-pv-claim
  labels:
    app: wordpress
spec:
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 20Gi
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: wordpress-mysql
  labels:
    app: wordpress
spec:
  selector:
    matchLabels:
      app: wordpress
      tier: mysql
  strategy:
    type: Recreate
  template:
    metadata:
      labels:
        app: wordpress
        tier: mysql
    spec:
      containers:
      - image: mysql:8.0
        name: mysql
        env:
        - name: MYSQL_ROOT_PASSWORD
          valueFrom:
            secretKeyRef:
              name: mysql-pass
              key: password
        - name: MYSQL_DATABASE
          value: wordpress
        - name: MYSQL_USER
          value: wordpress
        - name: MYSQL_PASSWORD
          valueFrom:
            secretKeyRef:
              name: mysql-pass
              key: password
        ports:
        - containerPort: 3306
          name: mysql
        volumeMounts:
        - name: mysql-persistent-storage
          mountPath: /var/lib/mysql
      volumes:
      - name: mysql-persistent-storage
        persistentVolumeClaim:
          claimName: mysql-pv-claim

创建Wordpress yaml

vim wordpress-deployment.yaml

wordpress-deployment.yaml描述了单实例 WordPress 容器将PersistentVolume挂载在/var/www/html 作为网站数据文件 。WORDPRESS_DB_HOST环境变量设置是上面定义的MySQL Service的名称。WORDPRESS_DB_PASSWORD 环境变量在kustomization中设置。

apiVersion: v1
kind: Service
metadata:
  name: wordpress
  labels:
    app: wordpress
spec:
  ports:
    - port: 80
  selector:
    app: wordpress
    tier: frontend
  type: LoadBalancer
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: wp-pv-claim
  labels:
    app: wordpress
spec:
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 20Gi
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: wordpress
  labels:
    app: wordpress
spec:
  selector:
    matchLabels:
      app: wordpress
      tier: frontend
  strategy:
    type: Recreate
  template:
    metadata:
      labels:
        app: wordpress
        tier: frontend
    spec:
      containers:
      - image: wordpress:6.2.1-apache
        name: wordpress
        env:
        - name: WORDPRESS_DB_HOST
          value: wordpress-mysql
        - name: WORDPRESS_DB_PASSWORD
          valueFrom:
            secretKeyRef:
              name: mysql-pass
              key: password
        - name: WORDPRESS_DB_USER
          value: wordpress
        ports:
        - containerPort: 80
          name: wordpress
        volumeMounts:
        - name: wordpress-persistent-storage
          mountPath: /var/www/html
      volumes:
      - name: wordpress-persistent-storage
        persistentVolumeClaim:
          claimName: wp-pv-claim

mysql 和wordpress的配置文件也可以从网上下载下来。

curl -LO https://k8s.io/examples/application/wordpress/mysql-deployment.yaml
curl -LO https://k8s.io/examples/application/wordpress/wordpress-deployment.yaml

将配置文件添加到kustomization.yaml文件中。

secretGenerator:
- name: mysql-pass
  literals:
  - password=123456
resources:
  - mysql-deployment.yaml
  - wordpress-deployment.yaml

一键部署

kubectl apply -k ./

有以下输出：

secret/mysql-pass-kkcc2b926b created
service/wordpress created
service/wordpress-mysql created
persistentvolumeclaim/mysql-pv-claim created
persistentvolumeclaim/wp-pv-claim created
deployment.apps/wordpress created
deployment.apps/wordpress-mysql created

验证 Secret 是否存在

kubectl get secrets
------
NAME                    TYPE     DATA   AGE
mysql-pass-kkcc2b926b   Opaque   1      26s

验证 PersistentVolume 是否已动态配置

kubectl get pvc
------
NAME             STATUS   VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS   AGE
mysql-pv-claim   Bound    pvc-2675097d-aec0-4f96-9e80-047588bcfd9a   20Gi       RWO            standard       94s
wp-pv-claim      Bound    pvc-d5d19a5c-d9c2-41d7-8de8-f7a1bec03fc1   20Gi       RWO            standard       94s

验证 Pod 是否正在运行

kubectl get pods
------
NAME                               READY   STATUS    RESTARTS   AGE
wordpress-65dcc8b9cd-bz875         1/1     Running   0          2m5s
wordpress-mysql-7646676cfc-98pxd   1/1     Running   0          2m5s

验证服务是否正在运行

kubectl get services wordpress
------
NAME        TYPE           CLUSTER-IP       EXTERNAL-IP   PORT(S)        AGE
wordpress   LoadBalancer   10.110.228.240   <pending>     80:30692/TCP   3m2s

获取 WordPress 服务的 IP 地址

minikube service wordpress --url
------
http://127.0.0.1:52551
❗  因为你正在使用 darwin 上的 Docker 驱动程序，所以需要打开终端才能运行它。

复制 IP 地址，然后在浏览器中加载页面以访问wordpress站点。

清除

清理所有服务执行kubectl delete -k ./即可。

kubectl delete -k ./
------
secret "mysql-pass-kkcc2b926b" deleted
service "wordpress" deleted
service "wordpress-mysql" deleted
persistentvolumeclaim "mysql-pv-claim" deleted
persistentvolumeclaim "wp-pv-claim" deleted
deployment.apps "wordpress" deleted
deployment.apps "wordpress-mysql" deleted