Why I have status CrashLoopBackOff of my MySQL pod?

Question

I am trying to run mysql database in Minikube. Installed Docker, Kubectl and Minikube and made these three files:

secret.yaml

apiVersion: v1
kind: Secret
metadata:
  name: mysql
type: Opaque
data:
  MYSQL_ROOT_PASSWORD: MTIzNA==

service.yaml

apiVersion: v1
kind: Service
metadata:
  name: app-mysql
  labels:
    app: mysql
    app.kubernetes.io/name: mysql
spec:
  ports:
  - name: mysql
    port: 3306
  clusterIP: None
  selector:
    app: mysql

statefulset.yaml

apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: mysql
spec:
  selector:
    matchLabels:
      app: mysql
      app.kubernetes.io/name: mysql
  serviceName: mysql
  replicas: 1
  template:
    metadata:
      labels:
        app: mysql
        app.kubernetes.io/name: mysql
    spec:
      containers:
      - name: mysql
        image: mysql:8.3.0
        envFrom:
          - secretRef:
              name: mysql
        ports:
        - name: mysql
          containerPort: 3306
        volumeMounts:
        - name: data
          mountPath: /var/lib/mysql
          subPath: mysql
        resources:
          requests:
            cpu: 500m
            memory: 1Gi
        livenessProbe:
          tcpSocket:
            port: 3306
          initialDelaySeconds: 30
          periodSeconds: 10
          timeoutSeconds: 5
        readinessProbe:
          tcpSocket:
            port: 3306
          initialDelaySeconds: 5
          periodSeconds: 2
          timeoutSeconds: 1
  volumeClaimTemplates:
  - metadata:
      name: data
    spec:
      accessModes: ["ReadWriteOnce"]
      resources:
        requests:
          storage: 2Gi

I applied them in the same order with kubectl apply -f <filename>. But when I get current running pods this one mysql-0 pod has status CrashLoopBackOff.

Tried to find some hints in logs. But it didn't really help.

2024-02-26 14:59:34+00:00 [Note] [Entrypoint]: Entrypoint script for MySQL Server 8.3.0-1.el8 started.
2024-02-26 14:59:34+00:00 [Note] [Entrypoint]: Switching to dedicated user 'mysql'
2024-02-26 14:59:34+00:00 [Note] [Entrypoint]: Entrypoint script for MySQL Server 8.3.0-1.el8 started.
'/var/lib/mysql/mysql.sock' -> '/var/run/mysqld/mysqld.sock'
2024-02-26T14:59:35.016581Z 0 [System] [MY-015015] [Server] MySQL Server - start.
2024-02-26T14:59:35.321366Z 0 [System] [MY-010116] [Server] /usr/sbin/mysqld (mysqld 8.3.0) starting as process 1
2024-02-26T14:59:35.329645Z 1 [System] [MY-013576] [InnoDB] InnoDB initialization has started.
2024-02-26T14:59:35.433059Z 1 [ERROR] [MY-012960] [InnoDB] Cannot create redo log files because data files are corrupt or the database was not shut down cleanly after creating the data files.
2024-02-26T14:59:35.433177Z 1 [ERROR] [MY-012930] [InnoDB] Plugin initialization aborted with error Generic error.
2024-02-26T14:59:35.855906Z 1 [ERROR] [MY-010334] [Server] Failed to initialize DD Storage Engine
2024-02-26T14:59:35.856297Z 0 [ERROR] [MY-010020] [Server] Data Dictionary initialization failed.
2024-02-26T14:59:35.856366Z 0 [ERROR] [MY-010119] [Server] Aborting
2024-02-26T14:59:35.858561Z 0 [System] [MY-010910] [Server] /usr/sbin/mysqld: Shutdown complete (mysqld 8.3.0)  MySQL Community Server - GPL.
2024-02-26T14:59:35.858638Z 0 [System] [MY-015016] [Server] MySQL Server - end.

Tried to delete service, statefulset, pvc, minikube image and container but nothing helps. I am new to kubernetes, could you tell please what I am missing?

Answer 1

As @Adiii mentioned, it may be that the data volume was corrupted. Aside from renaming the template, you can consider deleting the existing StatefulSet and PersistentVolumeClaim and allow Kubernetes to recreate a new one with clean data.

kubectl delete statefulset mysql

kubectl delete pvc data-mysql-0

After deleting the StatefulSet and PersistentVolumeClaim, reapply your deployment configurations (secret, service and statefulset) using kubectl apply -f commands. It will trigger the creation of a new pod with a fresh instance of MySQL and hopefully resolve the CrashLoopBackOff issue.