k8s使用ceph实现动态持久化存储 https://juejin.im/post/5b766b5bf265da27e36efdfa 96 CountingStars_ 2018.08.17 14:37* 字数 435 阅读 3432评论 1喜欢 3 简介 本文章介绍如何使用ceph为k8s提供动态申请pv的功能。ceph提供底层存储功能，cephfs方式支持k8s的pv的3种访问模式ReadWriteOnce，ReadOnlyMany ，ReadWriteMany ，RBD支持ReadWriteOnce，ReadOnlyMany两种模式
访问模式只是能力描述，并不是强制执行的，对于没有按pvc声明的方式使用pv，存储提供者应该负责访问时的运行错误。例如如果设置pvc的访问模式为ReadOnlyMany ，pod挂载后依然可写，如果需要真正的不可写，申请pvc是需要指定 readOnly: true 参数
部署 部署k8s centos7使用kubeadm安装k8s-1.11版本
部署ceph centos7安装ceph分布式存储集群
在k8s集群中配置使用ceph 使用Ceph RBD 使用kubeadm安装集群的额外配置
如果使用kubeadm部署的集群需要这些额外的步骤
由于使用动态存储时 controller-manager 需要使用 rbd 命令创建 image
所以 controller-manager 需要使用 rbd 命令
由于官方controller-manager镜像里没有rbd命令
如果没使用如下方式会报错无法成功创建pvc
相关 issue https://github.com/kubernetes/kubernetes/issues/38923
cat >external-storage-rbd-provisioner.yaml<<EOF apiVersion: v1 kind: ServiceAccount metadata: name: rbd-provisioner namespace: kube-system
kind: ClusterRole apiVersion: rbac.authorization.k8s.io/v1 metadata: name: rbd-provisioner rules:
- apiGroups: [""] resources: ["persistentvolumes"] verbs: ["get", "list", "watch", "create", "delete"]
- apiGroups: [""] resources: ["persistentvolumeclaims"] verbs: ["get", "list", "watch", "update"]
- apiGroups: ["storage.k8s.io"] resources: ["storageclasses"] verbs: ["get", "list", "watch"]
- apiGroups: [""] resources: ["events"] verbs: ["create", "update", "patch"]
- apiGroups: [""] resources: ["endpoints"] verbs: ["get", "list", "watch", "create", "update", "patch"]
- apiGroups: [""] resources: ["services"] resourceNames: ["kube-dns"] verbs: ["list", "get"]
kind: ClusterRoleBinding apiVersion: rbac.authorization.k8s.io/v1 metadata: name: rbd-provisioner subjects:
- kind: ServiceAccount name: rbd-provisioner namespace: kube-system roleRef: kind: ClusterRole name: rbd-provisioner apiGroup: rbac.authorization.k8s.io
apiVersion: rbac.authorization.k8s.io/v1 kind: Role metadata: name: rbd-provisioner namespace: kube-system rules:
- apiGroups: [""] resources: ["secrets"] verbs: ["get"]
apiVersion: rbac.authorization.k8s.io/v1 kind: RoleBinding metadata: name: rbd-provisioner namespace: kube-system roleRef: apiGroup: rbac.authorization.k8s.io kind: Role name: rbd-provisioner subjects:
- kind: ServiceAccount name: rbd-provisioner namespace: kube-system
apiVersion: extensions/v1beta1 kind: Deployment metadata: name: rbd-provisioner namespace: kube-system spec: replicas: 1 strategy: type: Recreate template: metadata: labels: app: rbd-provisioner spec: containers: - name: rbd-provisioner image: "quay.io/external_storage/rbd-provisioner:v2.0.0-k8s1.11" env: - name: PROVISIONER_NAME value: ceph.com/rbd serviceAccount: rbd-provisioner EOF kubectl apply -f external-storage-rbd-provisioner.yaml
查看状态 等待running之后 再进行后续的操作
kubectl get pod -n kube-system 配置 storageclass
在k8s集群中所有节点安装 ceph-common
需要使用kubelet使用rdb命令map附加rbd创建的image
yum install -y ceph-common
创建 osd pool 在ceph的mon或者admin节点
ceph osd pool create kube 4096 ceph osd pool ls
创建k8s访问ceph的用户 在ceph的mon或者admin节点
ceph auth get-or-create client.kube mon 'allow r' osd 'allow class-read object_prefix rbd_children, allow rwx pool=kube' -o ceph.client.kube.keyring
查看key 在ceph的mon或者admin节点
ceph auth get-key client.admin ceph auth get-key client.kube
创建 admin secret
CEPH_ADMIN_SECRET 替换为 client.admin 获取到的key
export CEPH_ADMIN_SECRET='AQBBAnRbSiSOFxAAEZXNMzYV6hsceccYLhzdWw=='
kubectl create secret generic ceph-secret --type="kubernetes.io/rbd"
--from-literal=key=$CEPH_ADMIN_SECRET
--namespace=kube-system
在 default 命名空间创建pvc用于访问ceph的 secret
CEPH_KUBE_SECRET 替换为 client.kube 获取到的key
export CEPH_KUBE_SECRET='AQBZK3VbTN/QOBAAIYi6CRLQcVevW5HM8lunOg=='
kubectl create secret generic ceph-user-secret --type="kubernetes.io/rbd"
--from-literal=key=$CEPH_KUBE_SECRET
--namespace=default
查看 secret
kubectl get secret ceph-user-secret -o yaml kubectl get secret ceph-secret -n kube-system -o yaml
配置 StorageClass
如果使用kubeadm创建的集群 provisioner 使用如下方式
provisioner: ceph.com/rbd
cat >storageclass-ceph-rdb.yaml<<EOF kind: StorageClass apiVersion: storage.k8s.io/v1 metadata: name: dynamic-ceph-rdb provisioner: ceph.com/rbd
provisioner: kubernetes.io/rbd
parameters: monitors: 11.11.11.111:6789,11.11.11.112:6789,11.11.11.113:6789 adminId: admin adminSecretName: ceph-secret adminSecretNamespace: kube-system pool: kube userId: kube userSecretName: ceph-user-secret fsType: ext4 imageFormat: "2" imageFeatures: "layering" EOF
创建
kubectl apply -f storageclass-ceph-rdb.yaml
查看
kubectl get sc 测试使用
创建pvc测试
cat >ceph-rdb-pvc-test.yaml<<EOF
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
name: ceph-rdb-claim
spec:
accessModes:
- ReadWriteOnce
storageClassName: dynamic-ceph-rdb
resources:
requests:
storage: 2Gi
EOF
kubectl apply -f ceph-rdb-pvc-test.yaml
查看
kubectl get pvc kubectl get pv
创建 nginx pod 挂载测试
cat >nginx-pod.yaml<<EOF apiVersion: v1 kind: Pod metadata: name: nginx-pod1 labels: name: nginx-pod1 spec: containers:
- name: nginx-pod1
image: nginx:alpine
ports:
- name: web containerPort: 80 volumeMounts:
- name: ceph-rdb mountPath: /usr/share/nginx/html volumes:
- name: ceph-rdb persistentVolumeClaim: claimName: ceph-rdb-claim EOF kubectl apply -f nginx-pod.yaml
查看
kubectl get pods -o wide
修改文件内容
kubectl exec -ti nginx-pod1 -- /bin/sh -c 'echo Hello World from Ceph RBD!!! > /usr/share/nginx/html/index.html'
访问测试
POD_ID=$(kubectl get pods -o wide | grep nginx-pod1 | awk '{print $(NF-1)}') curl http://$POD_ID
清理
kubectl delete -f nginx-pod.yaml kubectl delete -f ceph-rdb-pvc-test.yaml 使用 CephFS linux内核需要4.10+，否则会出现无法正常使用的问题，详细issue信息 https://github.com/kubernetes-incubator/external-storage/issues/345 centos7升级内核
在ceph集群创建CephFS
如下操作在ceph的mon或者admin节点
CephFS需要使用两个Pool来分别存储数据和元数据
ceph osd pool create fs_data 128 ceph osd pool create fs_metadata 128 ceph osd lspools
创建一个CephFS
ceph fs new cephfs fs_metadata fs_data
查看
ceph fs ls 部署cephfs-provisioner
官方没有cephfs动态卷支持
使用社区提供的cephfs-provisioner
cat >external-storage-cephfs-provisioner.yaml<<EOF apiVersion: v1 kind: ServiceAccount metadata: name: cephfs-provisioner namespace: kube-system
kind: ClusterRole apiVersion: rbac.authorization.k8s.io/v1 metadata: name: cephfs-provisioner rules:
- apiGroups: [""] resources: ["persistentvolumes"] verbs: ["get", "list", "watch", "create", "delete"]
- apiGroups: [""] resources: ["persistentvolumeclaims"] verbs: ["get", "list", "watch", "update"]
- apiGroups: ["storage.k8s.io"] resources: ["storageclasses"] verbs: ["get", "list", "watch"]
- apiGroups: [""] resources: ["events"] verbs: ["create", "update", "patch"]
- apiGroups: [""] resources: ["endpoints"] verbs: ["get", "list", "watch", "create", "update", "patch"]
- apiGroups: [""] resources: ["secrets"] verbs: ["create", "get", "delete"]
kind: ClusterRoleBinding apiVersion: rbac.authorization.k8s.io/v1 metadata: name: cephfs-provisioner subjects:
- kind: ServiceAccount name: cephfs-provisioner namespace: kube-system roleRef: kind: ClusterRole name: cephfs-provisioner apiGroup: rbac.authorization.k8s.io
apiVersion: rbac.authorization.k8s.io/v1 kind: Role metadata: name: cephfs-provisioner namespace: kube-system rules:
- apiGroups: [""] resources: ["secrets"] verbs: ["create", "get", "delete"]
apiVersion: rbac.authorization.k8s.io/v1 kind: RoleBinding metadata: name: cephfs-provisioner namespace: kube-system roleRef: apiGroup: rbac.authorization.k8s.io kind: Role name: cephfs-provisioner subjects:
- kind: ServiceAccount name: cephfs-provisioner namespace: kube-system
apiVersion: extensions/v1beta1 kind: Deployment metadata: name: cephfs-provisioner namespace: kube-system spec: replicas: 1 strategy: type: Recreate template: metadata: labels: app: cephfs-provisioner spec: containers: - name: cephfs-provisioner image: "quay.io/external_storage/cephfs-provisioner:v2.0.0-k8s1.11" env: - name: PROVISIONER_NAME value: ceph.com/cephfs command: - "/usr/local/bin/cephfs-provisioner" args: - "-id=cephfs-provisioner-1" serviceAccount: cephfs-provisioner EOF kubectl apply -f external-storage-cephfs-provisioner.yaml
查看状态 等待running之后 再进行后续的操作
kubectl get pod -n kube-system 配置 storageclass
查看key 在ceph的mon或者admin节点
ceph auth get-key client.admin
创建 admin secret
CEPH_ADMIN_SECRET 替换为 client.admin 获取到的key
如果在测试 ceph rbd 方式已经添加 可以略过此步骤
export CEPH_ADMIN_SECRET='AQBBAnRbSiSOFxAAEZXNMzYV6hsceccYLhzdWw=='
kubectl create secret generic ceph-secret --type="kubernetes.io/rbd"
--from-literal=key=$CEPH_ADMIN_SECRET
--namespace=kube-system
查看 secret
kubectl get secret ceph-secret -n kube-system -o yaml
配置 StorageClass
cat >storageclass-cephfs.yaml<<EOF kind: StorageClass apiVersion: storage.k8s.io/v1 metadata: name: dynamic-cephfs provisioner: ceph.com/cephfs parameters: monitors: 11.11.11.111:6789,11.11.11.112:6789,11.11.11.113:6789 adminId: admin adminSecretName: ceph-secret adminSecretNamespace: "kube-system" claimRoot: /volumes/kubernetes EOF
创建
kubectl apply -f storageclass-cephfs.yaml
查看
kubectl get sc 测试使用
创建pvc测试
cat >cephfs-pvc-test.yaml<<EOF
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
name: cephfs-claim
spec:
accessModes:
- ReadWriteOnce
storageClassName: dynamic-cephfs
resources:
requests:
storage: 2Gi
EOF
kubectl apply -f cephfs-pvc-test.yaml
查看
kubectl get pvc kubectl get pv
创建 nginx pod 挂载测试
cat >nginx-pod.yaml<<EOF apiVersion: v1 kind: Pod metadata: name: nginx-pod1 labels: name: nginx-pod1 spec: containers:
- name: nginx-pod1
image: nginx:alpine
ports:
- name: web containerPort: 80 volumeMounts:
- name: cephfs mountPath: /usr/share/nginx/html volumes:
- name: cephfs persistentVolumeClaim: claimName: cephfs-claim EOF kubectl apply -f nginx-pod.yaml
查看
kubectl get pods -o wide
修改文件内容
kubectl exec -ti nginx-pod1 -- /bin/sh -c 'echo Hello World from CephFS!!! > /usr/share/nginx/html/index.html'
访问测试
POD_ID=$(kubectl get pods -o wide | grep nginx-pod1 | awk '{print $(NF-1)}') curl http://$POD_ID
清理
kubectl delete -f nginx-pod.yaml kubectl delete -f cephfs-pvc-test.yaml
