k8s 运行 mysql 报错 initialize specified but the data directory has files in it

最近在 k8s 上面运行 mysql 报错

$ kubectl -n devops logs mysql-679745f64f-4cdzc 
2021-12-10 01:18:26+00:00 [Note] [Entrypoint]: Entrypoint script for MySQL Server 5.7.36-1debian10 started.
2021-12-10 01:18:26+00:00 [Note] [Entrypoint]: Switching to dedicated user 'mysql'
2021-12-10 01:18:26+00:00 [Note] [Entrypoint]: Entrypoint script for MySQL Server 5.7.36-1debian10 started.
2021-12-10 01:18:26+00:00 [Note] [Entrypoint]: Initializing database files
2021-12-10T01:18:26.354668Z 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
2021-12-10T01:18:26.355814Z 0 [ERROR] --initialize specified but the data directory has files in it. Aborting.
2021-12-10T01:18:26.355851Z 0 [ERROR] Aborting

提示数据目录非空，什么鬼，好吧，我们先运行一个 initContainers 看看目录里面到底有啥

      initContainers:
      - name: init-data-path
        image: hub.leffss.com/library/busybox:v1.28.4
        imagePullPolicy: IfNotPresent
        command: ["sh", "-c", "ls -l /var/lib/mysql"]
        securityContext:
          privileged: true
        volumeMounts:
        - name: mysql-pvc
          mountPath: /var/lib/mysql

# 查看 initContainers 的日志
kubectl -n devops logs mysql-679745f64f-4cdzc -c init-data-path
total 16
drwx------    2 root     root         16384 Dec 10 01:18 lost+found

原来是 lost+found，这个目录啥东西，有啥用这里就不介绍了，自己百度，反正以我工作这么多年的经验来说，没啥用

为啥会有这个目录呢？因为我们 pvc 使用的是 ceph 的 rbd，每次创建时都会格式化，就会产生这个，如果使用 cephfs 或者 nfs 的话，不会有这个目录

好吧，既然没用，那就盘它：

      initContainers:
      - name: init-data-path
        image: hub.leffss.com/library/busybox:v1.28.4
        imagePullPolicy: IfNotPresent
        command: ["sh", "-c"]
        args:
        - |
          if [[ -d /var/lib/mysql/lost+found ]];then
            echo "rm -rf /var/lib/mysql/lost+found"
            rm -rf /var/lib/mysql/lost+found
          else
            echo "/var/lib/mysql/lost+found not exist"
          fi
        securityContext:
          privileged: true
        volumeMounts:
        - name: mysql-pvc
          mountPath: /var/lib/mysql

删除，整个世界清净了！

$ kubectl -n devops get pod
NAME                     READY   STATUS    RESTARTS   AGE
mysql-774868b794-8d258   1/1     Running   0          13m
redis-7b4c48fd74-g99zg   1/1     Running   0          32m