k8s集成cephfs(StorageClass方式)
k8s 中 pv 有以下三种访问模式(Access Mode):
- ReadWriteOnce:只可被一个Node挂载,这个Node对PV拥有读写权限
- ReadOnlyMany: 可以被多个Node挂载,这些Node对PV只有只读权限
- ReadWriteMany: 可以被多个Node挂载,这些Node对PV拥有读写权限
ceph rbd 模式是不支持 ReadWriteMany,而 cephfs 是支持的,详见官方文档 Persistent Volumes | Kubernetes
还有一点,当创建 ceph rbd 的 storageclass 时,k8s 官方集成了 provisioner 的,只需指定 provisioner: kubernetes.io/rbd 即可;
而 cephfs 的 provisioner 当前是并未集成的,所以需要额外自行安装 cephfs-provisioner,具体方法如下:
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ceph 集群创建 cephfs
ceph-deploy mds create ceph01 ceph-deploy mds create ceph02 ceph-deploy mds create ceph03 ceph osd pool create cephfs_data 64 ceph osd pool create cephfs_metadata 64 ceph fs new cephfs cephfs_metadata cephfs_data ceph fs ls
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获取 key
$ ceph auth get-key client.admin | base64 QVFEMjVxVmhiVUNJRHhBQUxwdmVHbUdNTWtXZjB6VXovbWlBY3c9PQ==
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k8s 集群节点安装 ceph-common,版本需和 ceph 集群一致
rpm -ivh http://download.ceph.com/rpm-luminous/el7/noarch/ceph-release-1-1.el7.noarch.rpm sed -i 's#download.ceph.com#mirrors.aliyun.com/ceph#g' /etc/yum.repos.d/ceph.repo yum install epel-release -y yum install -y ceph-common
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安装 cephfs-provisioner
git clone https://github.com/kubernetes-retired/external-storage.git cd external-storage/ceph/cephfs/deploy kubectl create namespace cephfs kubectl -n cephfs apply -f ./rbac/
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编辑 storageclass yaml 文件
$ vi ceph-sc.yaml apiVersion: v1 kind: Secret metadata: name: cephfs-storageclass-secret namespace: cephfs data: key: QVFEMjVxVmhiVUNJRHhBQUxwdmVHbUdNTWtXZjB6VXovbWlBY3c9PQ== --- apiVersion: storage.k8s.io/v1 kind: StorageClass metadata: name: cephfs-leffss annotations: storageclass.kubernetes.io/is-default-class: "false" provisioner: ceph.com/cephfs parameters: monitors: 10.10.10.51:6789,10.10.10.53:6789,10.10.10.53:6789 # 不能使用主机名方式,因为前面安装的 cephfs-provisioner 的 pod 是无法访问的 #monitors: ceph01:6789,ceph02:6789,ceph03:6789 adminId: admin adminSecretName: cephfs-storageclass-secret adminSecretNamespace: cephfs claimRoot: /k8s-volumes
测试 yaml:
kind: PersistentVolumeClaim apiVersion: v1 metadata: name: ceph-pvc-test1 namespace: default annotations: volume.beta.kubernetes.io/storage-class: cephfs-leffss spec: accessModes: - ReadWriteMany resources: requests: storage: 1Gi --- kind: Pod apiVersion: v1 metadata: name: test-pod-1 spec: containers: - name: test-pod-1 image: hub.leffss.com/library/busybox:v1.29.2 command: - "/bin/sh" args: - "-c" - "touch /mnt/SUCCESS-ceph-pvc-test1 && exit 0 || exit 1" volumeMounts: - name: pvc mountPath: "/mnt" restartPolicy: "Never" volumes: - name: pvc persistentVolumeClaim: claimName: ceph-pvc-test1 kind: PersistentVolumeClaim apiVersion: v1 metadata: name: ceph-pvc-test2 namespace: default spec: storageClassName: cephfs-leffss accessModes: - ReadWriteMany resources: requests: storage: 1Gi --- kind: Pod apiVersion: v1 metadata: name: test-pod-2 spec: containers: - name: test-pod-2 image: hub.leffss.com/library/busybox:v1.29.2 command: - "/bin/sh" args: - "-c" - "touch /mnt/SUCCESS-ceph-pvc-test2 && exit 0 || exit 1" volumeMounts: - name: pvc mountPath: "/mnt" restartPolicy: "Never" volumes: - name: pvc persistentVolumeClaim: claimName: ceph-pvc-test2
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验证
$ ceph auth get-key client.admin AQD25qVhbUCIDxAALpveGmGMMkWf0zUz/miAcw== $ mkdir /mycephfs $ mount -t ceph ceph01:6789,ceph02:6789,ceph03:6789:/ /mycephfs -o name=admin,secret=AQD25qVhbUCIDxAALpveGmGMMkWf0zUz/miAcw== $ tree /mycephfs /mycephfs └── k8s-volumes ├── kubernetes │ ├── kubernetes-dynamic-pvc-59ea31d4-52a4-11ec-962a-567006a2be7a │ │ └── SUCCESS-ceph-pvc-test1 │ └── kubernetes-dynamic-pvc-6553ea70-52a4-11ec-962a-567006a2be7a │ └── SUCCESS-ceph-pvc-test2 ├── _kubernetes:kubernetes-dynamic-pvc-59ea31d4-52a4-11ec-962a-567006a2be7a.meta └── _kubernetes:kubernetes-dynamic-pvc-6553ea70-52a4-11ec-962a-567006a2be7a.meta 4 directories, 4 filess
最后说一点:cephfs 不太稳定,建议生产不要使用,我在测试环境都会遇到使用 cephfs 后导致 ceph 集群异常的情况