在k8s中使用CronJob定时备份mysql

在Kubernetes中，备份MySQL最常见的方案：
CronJob + mysqldump方案

kind: CronJob
apiVersion: batch/v1
metadata:
  name: mysql1-backup
  namespace: middleware-mysql
spec:
  schedule: 0/10 * * * *
  concurrencyPolicy: Allow
  suspend: false
  jobTemplate:
    metadata:
      creationTimestamp: null
    spec:
      template:
        spec:
          volumes:
            - name: backup-volume
              persistentVolumeClaim:
                claimName: mysql1-backup
          containers:
            - resources: {}
              terminationMessagePath: /dev/termination-log
              name: mysql1-backup
              command:
                - /bin/sh
                - '-c'
              env:
                - name: DB_HOST
                  value: mysql1.middleware-mysql
                - name: DB_USER
                  value: root
                - name: DB_PASSWORD
                  valueFrom:
                    secretKeyRef:
                      name: mysql1
                      key: mysql-root-password
                - name: DB_NAME
                  value: test
                - name: TZ
                  value: Asia/Shanghai
              imagePullPolicy: IfNotPresent
              volumeMounts:
                - name: backup-volume
                  mountPath: /mnt/backup
              terminationMessagePolicy: File
              image: 'mysql:5.7.30'
              args:
                - |
                  echo "starting backup database ${DB_NAME}..."
                  mysqldump -h ${DB_HOST} -u ${DB_USER} -p${DB_PASSWORD} ${DB_NAME} > /mnt/backup/${DB_NAME}-$(date +\%F-\%H\%M\%S).sql
                  echo "finished backup database ${DB_NAME}..."
                  echo "start cleaning old backup files , remain three "
                  cd /mnt/backup && ls -1t *.sql | awk 'NR>3' | xargs rm -f
          restartPolicy: OnFailure
  successfulJobsHistoryLimit: 3
  failedJobsHistoryLimit: 1

在此之前，我们要创建一个PVC：

kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: mysql1-backup
  namespace: middleware-mysql
spec:
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 500Gi
  storageClassName: 'your_storageclassname'
  volumeMode: Filesystem
status:
  phase: Bound
  accessModes:
    - ReadWriteOnce
  capacity:
    storage: 500Gi