Kubernetes部署會填充錯誤的持久卷

Question

我正在嘗試創建兩個部署，一個用於Wordpress，另一個用於MySQL，這是指兩個不同的持久卷。

有時 ，在刪除和重新創建卷和部署時，MySQL部署會填充Wordpress卷（最后是wordpress-volume目錄中的數據庫）。

當您執行kubectl get pv --namespace my-namespace時，這更清楚：

mysql-volume       2Gi   RWO  Retain  Bound  flashart-it/wordpress-volume-claim   manual                   1h
wordpress-volume   2Gi   RWO  Retain  Bound  flashart-it/mysql-volume-claim       manual

。

我很確定設置沒問題。 請在下面找到yaml文件。

永久體積聲明+永久體積

kind: PersistentVolume
apiVersion: v1
metadata:
  namespace: my-namespace
  name: mysql-volume
  labels:
    type: local
spec:
  storageClassName: manual
  capacity:
    storage: 2Gi
  accessModes:
    - ReadWriteOnce
  hostPath:
    path: /path/to/mount/mysql-volume
---
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  namespace: my-namespace
  name: mysql-volume-claim
spec:
  storageClassName: manual
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 2Gi
---
kind: PersistentVolume
apiVersion: v1
metadata:
  namespace: my-namespace
  name: wordpress-volume
  labels:
    type: local
spec:
  storageClassName: manual
  capacity:
    storage: 2Gi
  accessModes:
    - ReadWriteOnce
  hostPath:
    path: /path/to/mount/wordpress-volume
---
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  namespace: my-namespace
  name: wordpress-volume-claim
spec:
  storageClassName: manual
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 2Gi

部署

kind: Deployment
apiVersion: apps/v1
metadata:
  name: wordpress
  namespace: my-namespace
  labels:
    app: wordpress
spec:
  selector:
    matchLabels:
      app: wordpress
      tier: frontend
  strategy:
    type: Recreate
  template:
    metadata:
      namespace: my-namespace
      labels:
        app: wordpress
        tier: frontend
    spec:
      containers:
      - image: wordpress:5.0-php7.1-apache
        name: wordpress
        env:
          # ...
        ports:
          # ...
        volumeMounts:
        - name: wordpress-volume
          mountPath: /var/www/html
      volumes:
      - name: wordpress-volume
        persistentVolumeClaim:
          claimName: wordpress-volume-claim
---
kind: Deployment
apiVersion: apps/v1
metadata:
  namespace: my-namespace
  name: wordpress-mysql
  labels:
    app: wordpress
spec:
  selector:
    matchLabels:
      app: wordpress
      tier: mysql
  strategy:
    type: Recreate
  template:
    metadata:
      namespace: my-namespace
      labels:
        app: wordpress
        tier: mysql
    spec:
      containers:
        - image: mysql:5.7
          name: mysql
          env:
            # ...
          ports:
            # ...
          volumeMounts:
            - name: mysql-volume
              mountPath: /var/lib/mysql
      volumes:
        - name: mysql-volume
          persistentVolumeClaim:
            claimName: mysql-volume-claim

Answer 1

這是Kubernetes中的預期行為。 只要存儲類別已匹配，訪問模式已匹配且存儲大小足夠，PVC即可綁定到任何可用的PV。 名稱不用於匹配PVC和PV。

針對您的方案的可能解決方案是在PVC上使用標簽選擇器來過濾合格的PV。

首先，為PV添加標簽（在這種情況下：app = mysql）

kind: PersistentVolume
apiVersion: v1
metadata:
  name: mysql-volume
  labels:
    app: mysql

然后，在PVC中添加標簽選擇器以過濾PV。

kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  namespace: my-namespace
  name: mysql-volume-claim
spec:
  storageClassName: manual
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 2Gi
  selector: 
    matchLabels: 
      app: mysql