How to create mysql service using local persistent volume to store the data on windows local machine

Question

I want that mysql pod doesn't remove all mysql data when I restart the computer.

I should be able to store the data in my machine, so when I reboot my computer and the mysql pod starts again, the databases are still there.

here are my yaml's:

storage-class.yaml

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: local-storage
provisioner: kubernetes.io/no-provisioner
volumeBindingMode: WaitForFirstConsumer

mysql-pv.yaml

apiVersion: v1
kind: PersistentVolume
metadata:
  name: mysql-pv-volume
  labels:
    type: local
spec:
  capacity:
    storage: 20Gi
  accessModes:
    - ReadWriteMany
  persistentVolumeReclaimPolicy: Retain
  volumeMode: Filesystem
  storageClassName: local-storage
  local:
    path: "C:\\mysql-volume" #2 \ for escape characters right?
  nodeAffinity:
    required:
      nodeSelectorTerms:
      - matchExpressions:
        - key: kubernetes.io/hostname
          operator: In
          values:
          - docker-desktop
  #hostPath:
   # path: /mysql-volume
    #type: DirectoryOrCreate
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: mysql-pv-claim
  labels:
    type: local
spec:
  storageClassName: local-storage
  accessModes:
    - ReadWriteMany
  resources:
    requests:
      storage: 20Gi

mysql-deployment.yaml

apiVersion: v1
kind: Service
metadata:
  name: mysql
  labels:
    app: mysql
spec:
  ports:
  - protocol: TCP
    port: 3306
    nodePort: 30001
  selector:        
    app: mysql
  type: NodePort
---
apiVersion: apps/v1 # for versions before 1.9.0 use apps/v1beta2
kind: Deployment
metadata:
  name: mysql
spec:
  selector:
    matchLabels:
      app: mysql
  strategy:
    type: Recreate
  template:
    metadata:
      labels:
        app: mysql
    spec:
      containers:
      - image: mysql-custom-img-here
        imagePullPolicy: IfNotPresent
        name: mysql
        env:
        - name: MYSQL_ROOT_PASSWORD
          valueFrom:
            secretKeyRef:
              name: db-secret
              key: mysql-root-password
        - name: MYSQL_USER
          valueFrom:
            secretKeyRef:
              name: db-secret
              key: mysql-user
        - name: MYSQL_PASSWORD
          valueFrom:
            secretKeyRef:
              name: db-secret
              key: mysql-password
        ports:
        - containerPort: 3306
          name: mysql
        volumeMounts:
        - name: mysql-persistent-storage
          mountPath: /var/lib/mysql
      volumes:
      - name: mysql-persistent-storage
        persistentVolumeClaim:
          claimName: mysql-pv-claim

After trying that, the first error I got was:

MountVolume.NewMounter initialization failed for volume "mysql-pv-volume" : path "C:\\mysql-volume" does not exist

Since im using windows, I guess that's the correct path right? Im using 2 "" for a escape character, Maybe the problem is here in the path, but not sure. If it is, how can I give my local path on my windows machine?

Then I changed the local: path: to /opt and the following error apeared:

initialize specified but the data directory has files in it.

log:

2020-09-24 12:53:00+00:00 [Note] [Entrypoint]: Entrypoint script for MySQL Server 5.7.31-1debian10 started.
2020-09-24 12:53:00+00:00 [Note] [Entrypoint]: Switching to dedicated user 'mysql'
2020-09-24 12:53:00+00:00 [Note] [Entrypoint]: Entrypoint script for MySQL Server 5.7.31-1debian10 started.
2020-09-24 12:53:00+00:00 [Note] [Entrypoint]: Initializing database files
2020-09-24T12:53:00.271130Z 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
2020-09-24T12:53:00.271954Z 0 [ERROR] --initialize specified but the data directory has files in it. Aborting.
2020-09-24T12:53:00.271981Z 0 [ERROR] Aborting

but if I change the mountPath: /var/lib/mysql to for example mountPath: /var/lib/mysql-test

It works, but not as expected(saving the data after rebooting the computer).

Even after removing the PV, PVC and MYSQL deployment/service, that same error keeps appearing. I even removed the volumes using the docker command, and changing my mysql custom image just to 'mysql:5.7' just in case, but the same initialize specified but the data directory has files in it. appears.

How does that happen, even when I remove the pod? mountPath is the container path, so the data should disappear.

And how can I give my local path in the persistentVolume?

Thanks for your time!

edit: forgot the tell that I already saw this: How to create a mysql kubernetes service with a locally mounted data volume?

I searched a lot, but no luck

Answer 1

I finally solved the problem...

The problem of initialize specified but the data directory has files in it. was answered by @Jakub

The MountVolume.NewMounter initialization failed for volume "mysql-pv-volume" : path "C:\\mysql-volume" does not exist .... I can't even believe the time spent because of this silly problem...

the correct path is: path: /c/mysql-volume after that, all worked as expected!

Answer 2

I am posting this as a community wiki answer for better visibility.

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If you have problem with initialize specified but the data directory has files in it then there is github issue which will help you.

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TLDR

• Use --ignore-db-dir=lost+found in your container
• Use older version of mysql, for example mysql:5.6

---

There are answers on github provided by @alexpls and @aklinkert

I had this issue with Kubernetes and MySQL 5.7.15 as well. Adding the suggestion from @yosifki to my container's definition got things working.

Here's an extract of my working YAML definition:

name: mysql-master
image: mysql:5.7
args:
  - "--ignore-db-dir=lost+found"

---

The exact same configuration is working for MySQL Version 5.6 with.