Alibaba cloud Kubernetes CSI practice - dynamic cloud disk volume

Posted by CleoK on Tue, 29 Oct 2019 19:58:08 +0100

Environmental preparation

For cluster creation, dependency configuration and CSI plug-in deployment, please refer to: CSI deployment details

Create dynamic PV

Create a dynamic volume PV from the following template:

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: disk-pvc
spec:
  accessModes:
  - ReadWriteOnce
  resources:
    requests:
      storage: 25Gi
  storageClassName: alicloud-disk-ssd

storage: defines the size of the application cloud disk, with a minimum of 20Gi;

storageClassName: defines the storage class used to create the cloud disk. Currently, it mainly supports the following four types of cloud disk.

Alicloud disk available: will try to create cloud disks in order of efficiency, ssd and essd;

Alicloud disk essd: create an essd type cloud disk;

Alicloud disk ssd: create a cloud disk of ssd type;

Alicloud disk efficiency: create an efficient cloud disk;

View PVC and PV: the name of PV generated by default = PVC + "-" + PVC UID

# kubectl get pvc
NAME       STATUS   VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS        AGE
disk-pvc   Bound    pvc-5e90da27-a458-11e9-8dec-00163e0a6ecc   25Gi       RWO            alicloud-disk-ssd   9s

# kubectl get pv
NAME                                       CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS   CLAIM              STORAGECLASS        REASON   AGE
pvc-5e90da27-a458-11e9-8dec-00163e0a6ecc   25Gi       RWO            Retain           Bound    default/disk-pvc   alicloud-disk-ssd            8s

# kubectl describe pv pvc-5e90da27-a458-11e9-8dec-00163e0a6ecc
Name:            pvc-5e90da27-a458-11e9-8dec-00163e0a6ecc
Labels:          <none>
Annotations:     pv.kubernetes.io/provisioned-by: diskplugin.csi.alibabacloud.com
Finalizers:      [kubernetes.io/pv-protection]
StorageClass:    alicloud-disk-ssd
Status:          Bound
Claim:           default/disk-pvc
Reclaim Policy:  Retain
Access Modes:    RWO
VolumeMode:      Filesystem
Capacity:        25Gi
Node Affinity:   <none>
Message:
Source:
    Type:              CSI (a Container Storage Interface (CSI) volume source)
    Driver:            diskplugin.csi.alibabacloud.com
    VolumeHandle:      d-bp190t0frv9044z60t79
    ReadOnly:          false
    VolumeAttributes:      storage.kubernetes.io/csiProvisionerIdentity=1562849418025-8081-diskplugin.csi.alibabacloud.com
                           type=cloud_ssd
Events:                <none>

Create application

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-disk
  labels:
    app: nginx
spec:
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:1.7.9
        ports:
        - containerPort: 80
        volumeMounts:
          - name: disk-pvc
            mountPath: "/data"
      volumes:
        - name: disk-pvc
          persistentVolumeClaim:
            claimName: disk-pvc

Verify mount, high availability

See pod,Verify that the cloud disk is successfully mounted and create a test file;
# kubectl get pod
NAME                          READY   STATUS    RESTARTS   AGE
nginx-disk-6d5659d745-vl4c4   1/1     Running   0          24s

# kubectl exec nginx-disk-6d5659d745-vl4c4 ls /data
lost+found
# kubectl exec nginx-disk-6d5659d745-vl4c4 mount | grep /data
/dev/vdc on /data type ext4 (rw,relatime,data=ordered)

# kubectl exec nginx-disk-6d5659d745-vl4c4 touch /data/test
# kubectl exec nginx-disk-6d5659d745-vl4c4 ls /data
lost+found
test

//Delete the Pod and check whether the reconstructed Pod data is stable;
# kubectl delete pod nginx-disk-6d5659d745-vl4c4
pod "nginx-disk-6d5659d745-vl4c4" deleted

# kubectl get pod
NAME                          READY   STATUS    RESTARTS   AGE
nginx-disk-6d5659d745-nz2pv   1/1     Running   0          5s

# kubectl exec nginx-disk-6d5659d745-nz2pv ls /data
lost+found
test

Topics: Web Server Nginx Kubernetes