k8s-ceph-rbd
k8s使用ceph实现动态持久化存储 https://juejin.im/post/5b766b5bf265da27e36efdfa
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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<
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
- name: PROVISIONER_NAME
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<
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<
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<
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: web
- 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<
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
- kind: ServiceAccount
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
- name: PROVISIONER_NAME
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=$CEPH_ADMIN_SECRET \
--namespace=kube-system
查看 secret
kubectl get secret ceph-secret -n kube-system -o yaml
配置 StorageClass
cat >storageclass-cephfs.yaml<
apiVersion: storage.k8s.io/v1
metadata:
name: dynamic-cephfs
provisioner: ceph.com/cephfs
parameters:
monitors: 11.11.11.111:6789,11.11.11.112:6789,11.11.11.113:6789
adminId: admin
adminSecretName: ceph-secret
adminSecretNamespace: "kube-system"
claimRoot: /volumes/kubernetes
EOF
创建
kubectl apply -f storageclass-cephfs.yaml
查看
kubectl get sc
测试使用
创建pvc测试
cat >cephfs-pvc-test.yaml<
apiVersion: v1
metadata:
name: cephfs-claim
spec:
accessModes:
- ReadWriteOnce
storageClassName: dynamic-cephfs
resources:
requests:
storage: 2Gi
EOF
kubectl apply -f cephfs-pvc-test.yaml
查看
kubectl get pvc
kubectl get pv
创建 nginx pod 挂载测试
cat >nginx-pod.yaml<
kind: Pod
metadata:
name: nginx-pod1
labels:
name: nginx-pod1
spec:
containers:
- name: nginx-pod1
image: nginx:alpine
ports:- name: web
containerPort: 80
volumeMounts: - name: cephfs
mountPath: /usr/share/nginx/html
volumes:
- name: web
- name: cephfs
persistentVolumeClaim:
claimName: cephfs-claim
EOF
kubectl apply -f nginx-pod.yaml
查看
kubectl get pods -o wide
修改文件内容
kubectl exec -ti nginx-pod1 -- /bin/sh -c 'echo Hello World from CephFS!!! > /usr/share/nginx/html/index.html'
访问测试
POD_ID=$(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