︿
Top
Home CentOS docker Kubernetes Install wordpress on Kubernetes feat PV／PVC

Install wordpress on Kubernetes feat PV／PVC

Add Comment , ,

Kubernetes 的概念裡所有資源皆物件，因此 Kubernetes 不關心他的持久化存儲對象是誰，可以是 iSCSI、Ceph、NFS 或是 Node 上的本機目錄，為了解耦 Pod 應用所綁定的持久化存儲對象，Kubernetes 引入了 PV／PVC 的觀念，所需 PV 存儲空間由存儲管理員提供，Kubernetes 管理員只管宣告 PVC 去綁定所需的存儲空間（PV），最後再由 Pod 指定 PVC 來掛載持久化存儲目錄。

上一集，我們已將基礎設施 Kubernetes Cluster 與相關套件給佈建完畢，這次我們要在 Kubernetes 上透過 Ingress + Deployment + Service + PVC 來部署常見的 Wordpress 網頁應用服務。




實驗環境規格

主機安裝的作業系統皆為 CentOS 7.9x64





替 Kubernetes 建置外部存儲池

由於是實驗環境，我們額外使用一台機器單獨安裝 nfs service 來快速搭建網路存儲服務

[root@nfs nfs]# yum install nfs-utils -y

配置分享目錄，指定為 /tmp/nfs

[root@nfs nfs]# mkdir -p /tmp/nfs
[root@nfs nfs]# mkdir -p /tmp/nfs/001 /tmp/nfs/002
[root@nfs nfs]# cat /etc/exports
/tmp/nfs        192.168.200.0/24(rw,sync,no_root_squash)

開啟 nfs 服務並預設每次開機啟動

[root@nfs nfs]# systemctl start nfs && systemctl enable nfs
[root@nfs nfs]# showmount -e localhost
Export list for localhost:
/tmp/nfs 192.168.200.0/24

防火牆放行 nfs 使用埠號

[root@nfs nfs]# firewall-cmd --permanent --add-service=nfs
[root@nfs nfs]# firewall-cmd --permanent --add-service=rpc-bind
[root@nfs nfs]# firewall-cmd --permanent --add-service=mountd
[root@nfs nfs]# firewall-cmd --reload




配置 PV/PVC

編寫 PV

apiVersion: v1
kind: PersistentVolume
metadata:
  name: 10g-disk001
spec:
  capacity:
    storage: 10Gi
  accessModes:
    - ReadWriteMany
  persistentVolumeReclaimPolicy: Retain
  nfs:
    path: /tmp/nfs/001
    server: 192.168.200.158

---
apiVersion: v1
kind: PersistentVolume
metadata:
  name: 10g-disk002
spec:
  capacity:
    storage: 10Gi
  accessModes:
    - ReadWriteMany
  persistentVolumeReclaimPolicy: Retain
  nfs:
    path: /tmp/nfs/002
    server: 192.168.200.158
[root@k8s-master wordpress]# kubectl apply -f ./wordpress-pv.yaml

編寫 PVC

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: wordpress-pvc
  namespace: default
spec:
  accessModes:
    - ReadWriteMany
  resources:
    requests:
      storage: 10Gi

---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: wordpress-mysql-pvc
  namespace: default
spec:
  accessModes:
    - ReadWriteMany
  resources:
    requests:
      storage: 10Gi
[root@k8s-master wordpress]# kubectl apply -f ./wordpress-pvc.yaml




配置 Wordpress

編寫 MySQL Pod 與對應的 Service

apiVersion: apps/v1
kind: Deployment
metadata:
  name: wordpress-mysql-deployment
  namespace: default
spec:
  replicas: 1
  selector:
    matchLabels:
      app: wordpress-mysql-app
  template:
    metadata:
      labels:
        app: wordpress-mysql-app
    spec:
      volumes:
        - name: wordpress-mysql-persistent-volume
          persistentVolumeClaim:
            claimName: wordpress-mysql-pvc
      containers:
      - name: wordpress-mysql
        image: mysql:8.0
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 3306
          name: dbport
        volumeMounts:
          - name: wordpress-mysql-persistent-volume
            mountPath: /var/lib/mysql
        env:
        - name: MYSQL_DATABASE
          value: wordpress
        - name: MYSQL_USER
          value: wordpress
        - name: MYSQL_PASSWORD
          value: wordpress
        - name: MYSQL_RANDOM_ROOT_PASSWORD  # 啟用隨機 root 密碼以確保安全
          value: '1'
        - name: TZ
          value: "Asia/Taipei"

---
apiVersion: v1
kind: Service
metadata:
  name: wordpress-mysql-service-clusterip
  namespace: default
spec:
  selector:
    app: wordpress-mysql-app
  type: ClusterIP
  ports:
  - port: 3306 # service所對應的clusterIP的端口
    targetPort: 3306 # service所對應的pod的端口
[root@k8s-master wordpress]# kubectl apply -f ./wordpress-mysql.yaml

編寫 Wordpress Pod、對應的 Service 與對外的 Ingress

apiVersion: apps/v1
kind: Deployment
metadata:
  name: wordpress-deployment
  namespace: default
spec:
  replicas: 1
  selector:
    matchLabels:
      app: wordpress-app
  template:
    metadata:
      labels:
        app: wordpress-app
    spec:
      volumes:
        - name: wordpress-persistent-volume
          persistentVolumeClaim:
            claimName: wordpress-pvc
      containers:
      - name: wordpress
        image: wordpress:php8.2
        ports:
        - containerPort: 80
          name: wdport
        volumeMounts:
          - name: wordpress-persistent-volume
            mountPath: /var/www/html
        env:
        - name: WORDPRESS_DB_HOST
          value: wordpress-mysql-service-clusterip # 透過service存取MySQL Pod
        - name: WORDPRESS_DB_NAME
          value: wordpress
        - name: WORDPRESS_DB_USER
          value: wordpress
        - name: WORDPRESS_DB_PASSWORD
          value: wordpress

---
apiVersion: v1
kind: Service
metadata:
  name: wordpress-service-clusterip
  namespace: default
spec:
  selector:
    app: wordpress-app
  type: ClusterIP
  ports:
  - port: 80 # service所對應的clusterIP的端口
    targetPort: 80 # service所對應的Pod的端口


---
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: ing-wordpress
  namespace: default
spec:
  ingressClassName: nginx
  rules:
    - host: wordpress.test.com
      http:
        paths:
          - pathType: Prefix
            backend:
              service:
                name: wordpress-service-clusterip
                port:
                  number: 80
            path: /
[root@k8s-master wordpress]# kubectl apply -f ./wordpress.yaml
由於兩個 Pod 同處一個命名空間，WORDPRESS_DB_HOST 寫入的主機名稱可以是 
Service name：wordpress-mysql-service-clusterip，也可以是完整 DNS 地址：
wordpress-mysql-service-clusterip.default.svc.cluster.local
生產環境中請將密碼寫在 configMap，Wordpress Deployment 的 replicas 參數可以視情況調高以實現高可用性




確認成果

檢查已建立的所有資源

[root@k8s-master wordpress]# kubectl get pv
NAME         CAPACITY  ACCESS MODES  RECLAIM  POLICY  STATUS  CLAIM                 STORAGECLASS   REASON   AGE
10g-disk001  10Gi      RWX           Retain           Bound   default/wordpress-pvc                         51m
10g-disk002  10Gi      RWX           Retain           Bound   default/wordpress-mysql-pvc                   51m

[root@k8s-master wordpress]# kubectl get pvc,pods,svc,ing -n default
NAME                                        STATUS   VOLUME        CAPACITY   ACCESS MODES   STORAGECLASS   AGE
persistentvolumeclaim/wordpress-mysql-pvc   Bound    10g-disk002   10Gi       RWX                           47m
persistentvolumeclaim/wordpress-pvc         Bound    10g-disk001   10Gi       RWX                           47m

NAME                                             READY   STATUS    RESTARTS   AGE
pod/wordpress-deployment-5594885cb7-fsjld        1/1     Running   0          47m
pod/wordpress-mysql-deployment-76bf56568-s4wtx   1/1     Running   0          47m

NAME                                        TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)    AGE
service/wordpress-mysql-service-clusterip   ClusterIP   10.106.170.74   <none>        3306/TCP   47m
service/wordpress-service-clusterip         ClusterIP   10.98.255.72    <none>        80/TCP     47m

NAME                                      CLASS   HOSTS            ADDRESS                           PORTS   AGE
ingress.networking.k8s.io/ing-wordpress   nginx   wordpress.test.com   192.168.200.161,192.168.200.162   80      47m

區網任一電腦的 hosts 檔案裡加入一筆 192.168.200.161 指向 wordpress.test.com 的資料，再透過電腦瀏覽器網址列輸入 http://wordpress.test.com 即可驗證我們的 wordpress 網頁應用服務！






本文內容參閱以下連結：

tomy

來自台灣的系統工程師，一直熱衷於 Open source 相關技術的學習、建置、應用與分享。

  • Image
  • Image
  • Image
  • Image
  • Image

0 Comments:

張貼留言

訂閱： 張貼留言 ( Atom )