kubernetes的ceph RBD volume(2): 使用Ceph RBD作为persistent volume

以下是使用ceph RBD作为persistent volume的例子：

A

PersistentVolume

(PV) is a piece of networked storage in the cluster that has been provisioned by an administrator. It is a resource in the cluster just like a node is a cluster resource. PVs are volume plugins like
Volumes, but have a lifecycle independent of any individual pod that uses the PV. This API object captures the details of the implementation of the storage, be that NFS, iSCSI, or a cloud-provider-specific storage system.

A

PersistentVolumeClaim

(PVC) is a request for storage by a user. It is similar to a pod. Pods consume node resources and PVCs consume PV resources. Pods can request specific levels of resources (CPU and Memory). Claims
can request specific size and access modes (e.g., can be mounted once read/write or many times read-only).

1. 先创建image在pool里。

2. 创建 PV

[root@testnew kube]# cat pv_ceph.yaml

apiVersion: v1

kind: PersistentVolume

metadata:

  name: ceph-pv

spec:

  capacity:

    storage: 50Gi

  accessModes:

    - ReadWriteOnce

  rbd:

    monitors:

     - 10.0.200.11:6789

     - 10.0.200.13:6789

     - 10.0.200.14:6789

    pool: kube

    image: vol2

    user: kube

    secretRef:

      name: ceph-secret

    fsType: ext4

    readOnly: false

  persistentVolumeReclaimPolicy: Recycle

kubectl create -f pv_ceph.yaml

[root@testnew kube]# kubectl get pv

NAME                                       CAPACITY   ACCESSMODES   RECLAIMPOLICY   STATUS    CLAIM                   REASON    AGE

ceph-pv                                    50Gi       RWO           Recycle         Bound     default/ceph-claim                4d

pvc-ac668f99-3b8b-11e7-8af9-fa163e01317b   20Gi       RWO           Delete          Bound     default/ceph-claim-sc             4d

3.  创建pvc

[root@testnew kube]# cat pvc_ceph.yaml

kind: PersistentVolumeClaim

apiVersion: v1

metadata:

  name: ceph-claim

spec:

  accessModes:

    - ReadWriteOnce

  resources:

    requests:

      storage: 20Gi

note: pvc和pv是一一对应的，所以storage在这设20G没用

kubectl create -f pvc_ceph.yaml

[root@testnew kube]# kubectl get pvc

NAME            STATUS    VOLUME                                     CAPACITY   ACCESSMODES   AGE

ceph-claim      Bound     ceph-pv                                    50Gi       RWO           4d

4. 创建pod

[root@testnew kube]# cat frontend-pvc-controller.yaml

apiVersion: v1

kind: ReplicationController

metadata:

  name: frontendpvc

  labels:

    name: frontendpvc

spec:

  replicas: 1

  selector:

    name: frontendpvc

  template:

    metadata:

      labels:

        name: frontendpvc

    spec:

      containers:

      - name: frontendpvc

        image: kubeguide/guestbook-php-frontend

        env:

        - name: GET_HOSTS_FROM

          value: env

        ports:

        - containerPort: 80

        volumeMounts:

        - mountPath: /mnt/rbd

          name: ceph-vol

      volumes:

      - name: ceph-vol

        persistentVolumeClaim:

          claimName: ceph-claim