Kubernetes持久体积与迷你管

Question

I'm fighting since many hours setting my k8s pods on my minikube single node, at persistent volume creation stage.

This command always ends with error, even if I copy/paste the example spec from kubernetes documentation :

$kubectl apply -f pv-volume.yml

error: SchemaError(io.k8s.api.core.v1.ScaleIOVolumeSource): invalid object doesn't have additional properties

$cat pv-volume.yml
kind: PersistentVolume
apiVersion: v1
metadata:
  name: task-pv-volume
  labels:
    type: local
spec:
  storageClassName: manual
  capacity:
    storage: 10Gi
  accessModes:
    - ReadWriteOnce
  hostPath:
    path: "/mnt/data"

I can't figure out why kubectl obliges me to specify ScaleIO in my spec, while I'm using local volume.

I've the same error specifying storagaClassName to standard

Any idea about what can be the problem?

My versions :

$minikube version
minikube version: v1.0.0

$kubectl version
Client Version: version.Info{Major:"1", Minor:"10", GitVersion:"v1.10.11", GitCommit:"637c7e288581ee40ab4ca210618a89a555b6e7e9", GitTreeState:"clean", BuildDate:"2018-11-26T14:38:32Z", GoVersion:"go1.9.3", Compiler:"gc", Platform:"darwin/amd64"}
Server Version: version.Info{Major:"1", Minor:"14", GitVersion:"v1.14.0", GitCommit:"641856db18352033a0d96dbc99153fa3b27298e5", GitTreeState:"clean", BuildDate:"2019-03-25T15:45:25Z", GoVersion:"go1.12.1", Compiler:"gc", Platform:"linux/amd64"}

Answer 1

In minikube , the dynamic provisioner is already there by default , you just need to create persistent volume claims using that Class.

C02W84XMHTD5:Downloads iahmad$ minikube start
Starting local Kubernetes v1.10.0 cluster...
Starting VM...
Getting VM IP address...
Moving files into cluster...
Setting up certs...
Connecting to cluster...
Setting up kubeconfig...
Starting cluster components...
Kubectl is now configured to use the cluster.
Loading cached images from config file.
C02W84XMHTD5:Downloads iahmad$ kubectl get nodes
NAME       STATUS   ROLES    AGE   VERSION
minikube   Ready    master   4d    v1.10.0
C02W84XMHTD5:Downloads iahmad$ 
C02W84XMHTD5:Downloads iahmad$ kubectl get storageclasses.storage.k8s.io 
NAME                 PROVISIONER                AGE
standard (default)   k8s.io/minikube-hostpath   4d
C02W84XMHTD5:Downloads iahmad$ 
C02W84XMHTD5:Downloads iahmad$ 

so for th data persistence to host , you just need a volume claim and use it on your kubernetes deployment.

example mysql volume claim using the built in minikube storage class.

kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: mysql-volumeclaim
  annotations:
    volume.beta.kubernetes.io/storage-class: standard
spec:
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 10Gi

Usage inside mysql deployment:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: mysql
  labels:
    app: mysql
spec:
  replicas: 1
  selector:
    matchLabels:
      app: mysql
  template:
    metadata:
      labels:
        app: mysql
    spec:
      containers:
        - image: mysql:5.6
          name: mysql
          env:
            - name: MYSQL_ROOT_PASSWORD
              valueFrom:
                secretKeyRef:
                  name: mysql
                  key: password
          ports:
            - containerPort: 3306
              name: mysql
          volumeMounts:
            - name: mysql-persistent-storage
              mountPath: /var/lib/mysql
      volumes:
        - name: mysql-persistent-storage
          persistentVolumeClaim:
            claimName: mysql-volumeclaim

Answer 2

I was going from error to error, then try to create another object such as secrets and the same issue.

Then

• I removed kubectl in turn, and reinstall it,
• I stop mikube and start it again

It looks like the kubectl upgrade was the key to the solution, 1.10 client version was trying to talk to 1.14 - and the mismatch in API version can explain the weirdness in the error messages. It seemed to be not really minikube related.

It's now working, I can actually run my kube commands without errors