kubernetes 使用ceph实现动态持久卷存储

k8s使用ceph存储

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

动态供给主要是能够自动帮你创建pv，需要多大的空间就创建多大的pv。k8s帮助创建pv，创建pvc就直接api调用存储类来寻找pv。

如果是存储静态供给的话，会需要我们手动去创建pv，如果没有足够的资源，找不到合适的pv，那么pod就会处于pending等待的状态。而动态供给主要的一个实现就是StorageClass存储对象，其实它就是声明你使用哪个存储，然后帮你去连接，再帮你去自动创建pv。 

使用Ceph RBD作为持久数据卷
配置 rbd-provisioner
1、编写yaml文件

[root@k8s-master ~]# 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: apps/v1
kind: Deployment
metadata:
name: rbd-provisioner
namespace: kube-system
spec:
selector:
matchLabels:
app: rbd-provisioner
replicas: 1
strategy:
type: Recreate
template:
metadata:
labels:
app: rbd-provisioner
spec:
containers:
- name: rbd-provisioner
image: "registry.cn-chengdu.aliyuncs.com/ives/rbd-provisioner:v2.0.0-k8s1.11"
env:
- name: PROVISIONER_NAME
value: ceph.com/rbd
serviceAccount: rbd-provisioner
EOF

2、创建相关资源

[root@k8s-master ~]# kubectl apply -f external-storage-rbd-provisioner.yaml

[root@k8s-master ~]# kubectl get pods -n kube-system |grep rbd
rbd-provisioner-7c77dcfd67-9xv2m 1/1 Running 0 59s

配置 storageclass

创建pod时，kubelet需要使用rbd命令去检测和挂载pv对应的ceph image，所以要在所有k8s的worker节点安装ceph客户端ceph-common。将ceph的ceph.client.admin.keyring和ceph.conf文件拷贝到master的/etc/ceph目录下。

1、安装ceph-common（k8s所有工作节点）

# yum -y install ceph-common
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2、创建 ​​osd pool​​，在ceph的mon或者admin节点

[root@ceph_node1 ~]# ceph osd pool create kube 8
pool 'kube' created

[root@ceph_node1 ~]# ceph osd pool ls
kube

3、创建k8s访问ceph的用户，在ceph的mon或者admin节点

[root@ceph_node1 ~]# 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
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4、查看key，在ceph的mon或者admin节点

[root@ceph_node1 ~]# ceph auth get-key client.admin
AQCzcPFeYnOoABAATaM1Wt8tMgvYTQjj6YEuVg==

[root@ceph_node1 ~]# ceph auth get-key client.kube
AQC5+vJehk7XIRAAr9mtGFHlUSfT7yQMANeWaw==

5、创建admin secret，在k8s管理节点

#CEPH_ADMIN_SECRET替换为 client.admin 获取到的key
[root@k8s-master ~]# export CEPH_ADMIN_SECRET='AQCzcPFeYnOoABAATaM1Wt8tMgvYTQjj6YEuVg=='

[root@k8s-master ~]# kubectl create secret generic ceph-secret --type="kubernetes.io/rbd" \
--from-literal=key=$CEPH_ADMIN_SECRET \
--namespace=kube-system

6、在default命名空间创建pvc用于访问ceph 的secret，在k8s管理节点

#CEPH_KUBE_SECRET替换为 client.kube 获取到的key
[root@k8s-master ~]# export CEPH_KUBE_SECRET='AQC5+vJehk7XIRAAr9mtGFHlUSfT7yQMANeWaw=='

[root@k8s-master ~]# kubectl create secret generic ceph-user-secret --type="kubernetes.io/rbd" \
--from-literal=key=$CEPH_KUBE_SECRET \
--namespace=default

7、查看secret

[root@k8s-master ~]# kubectl get secret ceph-user-secret -o yaml
[root@k8s-master ~]# kubectl get secret ceph-secret -n kube-system -o yaml

8、配置StorageClass

[root@k8s-master ~]# cat >storageclass-ceph-rdb.yaml<<EOF
kind: StorageClass
apiVersion: storage.k8s.io/v1
metadata:
name: dynamic-ceph-rdb
provisioner: ceph.com/rbd
parameters:
monitors: 192.168.3.27:6789,192.168.3.60:6789,192.168.3.95:6789
adminId: admin
adminSecretName: ceph-secret
adminSecretNamespace: kube-system
pool: kube
userId: kube
userSecretName: ceph-user-secret
fsType: ext4
imageFormat: "2"
imageFeatures: "layering"
EOF

9、创建StorageClass

[root@k8s-master ~]# kubectl apply -f storageclass-ceph-rdb.yaml
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10、查看

[root@k8s-master ~]# kubectl get sc
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测试使用
1、创建pvc测试

[root@k8s-master ~]# 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

[root@k8s-master ~]# kubectl apply -f ceph-rdb-pvc-test.yaml
persistentvolumeclaim/ceph-rdb-claim created

2、查看pvc和pv

[root@k8s-master ~]# kubectl get pvc
NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE
ceph-rdb-claim Bound pvc-bd2363f1-a841-46d0-ad54-99267173bc04 2Gi RWO dynamic-ceph-rdb 16s

[root@k8s-master ~]# kubectl get pv
NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS CLAIM STORAGECLASS REASON AGE
pvc-bd2363f1-a841-46d0-ad54-99267173bc04 2Gi RWO Delete Bound default/ceph-rdb-claim dynamic-ceph-rdb 29s

3、编写nginx pod资源配置清单进行测试

[root@k8s-master ~]# 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

4、创建pod 并查看

[root@k8s-master ~]# kubectl apply -f nginx-pod.yaml
pod/nginx-pod1 created

[root@k8s-master ~]# kubectl get pods
NAME READY STATUS RESTARTS AGE
nginx-pod1 1/1 Running 0 2m25s

[root@k8s-master ~]# kubectl get pods -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
nginx-pod1 1/1 Running 0 2m34s 10.244.1.5 k8s-node1 <none> <none>

5、修改文件内容

[root@k8s-master ~]# kubectl exec -it nginx-pod1 -- /bin/sh -c 'echo Hello World from Ceph RBD!!! > /usr/share/nginx/html/index.html'
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6、访问测试

[root@k8s-master ~]# POD_IP=$(kubectl get pods -o wide |grep nginx-pod1 |awk '{print $(NF-3)}')
[root@k8s-master ~]# curl $POD_IP
Hello World from Ceph RBD!!!

7、清理

[root@k8s-master ~]# kubectl delete -f nginx-pod.yaml

[root@k8s-master ~]# kubectl delete -f ceph-rdb-pvc-test.yaml

使用CephFS作为持久数据卷
Ceph端创建CephFS pool
1、创建两个pool分别存储数据和元数据，在ceph的mon或者admin节点 （这里测试，所以只给了8个pg_num）

[root@ceph_node1 ~]# ceph osd pool create fs_data 8
pool 'fs_data' created
[root@ceph_node1 ~]# ceph osd pool create fs_metadata 8
pool 'fs_metadata' created

2、创建一个CephFS，在ceph的mon或者admin节点

[root@ceph_node1 ~]# ceph fs new cephfs fs_metadata fs_data
new fs with metadata pool 8 and data pool 7

3、查看

[root@ceph_node1 ~]# ceph fs ls
name: cephfs, metadata pool: fs_metadata, data pools: [fs_data ]

配置 cephfs-provisioner

官方没有提供cephfs动态卷支持，使用社区提供的cephfs-provisioner

1、编写yaml文件

[root@k8s-master ~]# 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: apps/v1
kind: Deployment
metadata:
name: cephfs-provisioner
namespace: kube-system
spec:
selector:
matchLabels:
app: cephfs-provisioner
replicas: 1
strategy:
type: Recreate
template:
metadata:
labels:
app: cephfs-provisioner
spec:
containers:
- name: cephfs-provisioner
image: "registry.cn-chengdu.aliyuncs.com/ives/cephfs-provisioner:latest"
env:
- name: PROVISIONER_NAME
value: ceph.com/cephfs
command:
- "/usr/local/bin/cephfs-provisioner"
args:
- "-id=cephfs-provisioner-1"
serviceAccount: cephfs-provisioner
EOF

2、创建相关资源

[root@k8s-master ~]# kubectl apply -f external-storage-cephfs-provisioner.yaml

[root@k8s-master ~]# kubectl get pods -n kube-system |grep cephfs
cephfs-provisioner-6d76ff6bd5-zzlmt 1/1 Running 0 28s
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配置 storageclass
1、查看key，在ceph的mon或者admin节点

[root@ceph_node1 ~]# ceph auth get-key client.admin
AQCzcPFeYnOoABAATaM1Wt8tMgvYTQjj6YEuVg==
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2、创建admin secret，在k8s管理节点

#CEPH_ADMIN_SECRET替换为 client.admin 获取到的key
[root@k8s-master ~]# export CEPH_ADMIN_SECRET='AQCzcPFeYnOoABAATaM1Wt8tMgvYTQjj6YEuVg=='

[root@k8s-master ~]# kubectl create secret generic ceph-secret --type="kubernetes.io/rbd" \
--from-literal=key=$CEPH_ADMIN_SECRET \
--namespace=kube-system
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3、查看secret

[root@k8s-master ~]# kubectl get secret ceph-secret -n kube-system -o yaml
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4、配置StorageClass

[root@k8s-master ~]# cat >storageclass-cephfs.yaml<<EOF
kind: StorageClass
apiVersion: storage.k8s.io/v1
metadata:
name: dynamic-cephfs
provisioner: ceph.com/cephfs
parameters:
monitors: 192.168.3.27:6789,192.168.3.60:6789,192.168.3.95:6789
adminId: admin
adminSecretName: ceph-secret
adminSecretNamespace: "kube-system"
claimRoot: /volumes/kubernetes
EOF
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5、创建StorageClass

[root@k8s-master ~]# kubectl apply -f storageclass-cephfs.yaml
storageclass.storage.k8s.io/dynamic-cephfs created
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6、查看

[root@k8s-master ~]# kubectl get sc
NAME PROVISIONER RECLAIMPOLICY VOLUMEBINDINGMODE ALLOWVOLUMEEXPANSION AGE
dynamic-cephfs ceph.com/cephfs Delete Immediate false 17s
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测试使用
1、创建pvc测试

[root@k8s-master ~]# cat >cephfs-pvc-test.yaml<<EOF
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
name: cephfs-claim
spec:
accessModes:
- ReadWriteMany
storageClassName: dynamic-cephfs
resources:
requests:
storage: 2Gi
EOF

[root@k8s-master ~]# kubectl apply -f cephfs-pvc-test.yaml
persistentvolumeclaim/cephfs-claim created

2、查看pv和pvc

[root@k8s-master ~]# kubectl get pvc
NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE
cephfs-claim Bound pvc-b8194840-2664-418c-bad1-df1a4b028f30 2Gi RWX dynamic-cephfs 3s

[root@k8s-master ~]# kubectl get pv |grep pvc
pvc-b8194840-2664-418c-bad1-df1a4b028f30 2Gi RWX Delete Bound default/cephfs-claim dynamic-cephfs 33s

3、编写nginx pod资源配置清单进行测试

[root@k8s-master ~]# cat >nginx-pod.yaml<<EOF
apiVersion: v1
kind: Pod
metadata:
name: nginx-pod2
labels:
name: nginx-pod2
spec:
containers:
- name: nginx-pod2
image: nginx
ports:
- name: web
containerPort: 80
volumeMounts:
- name: cephfs
mountPath: /usr/share/nginx/html
volumes:
- name: cephfs
persistentVolumeClaim:
claimName: cephfs-claim
EOF

4、创建pod 并查看

[root@k8s-master ~]# kubectl apply -f nginx-pod.yaml
pod/nginx-pod2 created

[root@k8s-master ~]# kubectl get pods
NAME READY STATUS RESTARTS AGE
nginx-pod2 1/1 Running 0 16s

[root@k8s-master ~]# kubectl get pods -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
nginx-pod2 1/1 Running 0 88s 10.244.1.7 k8s-node1 <none> <none>

5、修改文件内容

[root@k8s-master ~]# kubectl exec -it nginx-pod2 -- /bin/sh -c 'echo Hello World from CephFS!!! > /usr/share/nginx/html/index.html'
6、访问测试

[root@k8s-master ~]# POD_IP=$(kubectl get pods -o wide |grep nginx-pod2 |awk '{print $(NF-3)}')

[root@k8s-master ~]# curl $POD_IP
Hello World from CephFS!!!
7、清理

[root@k8s-master ~]# kubectl delete -f nginx-pod.yaml

[root@k8s-master ~]# kubectl delete -f cephfs-pvc-test.yaml