kubernetes使用ceph存储

仲卿發表於 2020-6-8 17:31:00

<h3 class="md-end-block md-heading md-focus">PV、PVC概述</h3>
管理存储是管理计算的一个明显问题。PersistentVolume子系统为用户和管理员提供了一个API，用于抽象如何根据消费方式提供存储的详细信息。于是引入了两个新的API资源：PersistentVolume和PersistentVolumeClaim
<blockquote>
PersistentVolume（PV）是集群中已由管理员配置的一段网络存储。集群中的资源就像一个节点是一个集群资源。 PV是诸如卷之类的卷插件，但是具有独立于使用PV的任何单个pod的生命周期。该API对象包含存储的实现细节，即NFS，iSCSI或云提供商特定的存储系统。 
</blockquote>
<blockquote>
PersistentVolumeClaim（PVC）是用户存储的请求。它类似于pod。Pod消耗节点资源，PVC消耗存储资源。 pod可以请求特定级别的资源（CPU和内存）。权限要求可以请求特定的大小和访问模式。
</blockquote>
<blockquote>
虽然PersistentVolumeClaims允许用户使用抽象存储资源，但是常见的是，用户需要具有不同属性（如性能）的PersistentVolumes，用于不同的问题。管理员需要能够提供多种不同于PersistentVolumes，而不仅仅是大小和访问模式，而不会使用户了解这些卷的实现细节。对于这些需求，存在StorageClass资源。
</blockquote>
<blockquote>
StorageClass为集群提供了一种描述他们提供的存储的“类”的方法。不同的类可能映射到服务质量级别，或备份策略，或者由群集管理员确定的任意策略。 Kubernetes本身对于什么类别代表是不言而喻的。这个概念有时在其他存储系统中称为“配置文件”
</blockquote>
<h5 class="md-end-block md-heading md-focus">POD动态供给</h5>
<blockquote>
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。
</blockquote>
<blockquote>
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。
</blockquote>
<h5 class="md-end-block md-heading md-focus">POD使用RBD做为持久数据卷</h5>
<h6>安装与配置</h6>
RBD支持ReadWriteOnce，ReadOnlyMany两种模式
1、配置rbd-provisioner
github仓库链接https://github.com/kubernetes-incubator/external-storage
<div class="cnblogs_code">
<pre># git clone https://github.com/kubernetes-incubator/external-storage.git
# cd external-storage/ceph/rbd/deploy
# NAMESPACE=kube-system
# sed -r -i "s/namespace: [^ ]+/namespace: $NAMESPACE/g" ./rbac/clusterrolebinding.yaml ./rbac/rolebinding.yaml
# kubectl -n $NAMESPACE apply -f ./rbac

# kubectl get pod -n kube-system
NAME READY STATUS RESTARTS AGE
coredns-575bd6d498-n995v 1/1 Running 1 13d
kube-flannel-ds-amd64-gplmm 1/1 Running 1 13d
kube-flannel-ds-amd64-jrrb9 1/1 Running 1 13d
kube-flannel-ds-amd64-ttcx4 1/1 Running 1 13d
rbd-provisioner-75b85f85bd-vr7t5 1/1 Running 0 72s</pre>
</div>
2、配置k8s访问ceph的用户
<div class="cnblogs_code">
<pre>1、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
yum -y install ceph-common
2、创建 osd pool 在ceph的mon或者admin节点
ceph osd pool create kube 128 128
ceph osd pool ls
3、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
4、查看key 在ceph的mon或者admin节点
# ceph auth get-key client.admin
AQCBrJ9eV/U5NBAAoDlM4gV3a+KNQDBOUqVxdw==
# ceph auth get-key client.kube
AQCZ96BeUgPkDhAAhxbWarZh9kTx2QbFCDM/rA==

5、创建 admin secret
kubectl create secret generic ceph-secret --type="kubernetes.io/rbd" \
--from-literal=key=AQCBrJ9eV/U5NBAAoDlM4gV3a+KNQDBOUqVxdw== \
--namespace=kube-system
# kubectl get secret -n kube-system |grep ceph
ceph-secret kubernetes.io/rbd 1 91s
6、在 default 命名空间创建pvc用于访问ceph的 secret
kubectl create secret generic ceph-user-secret --type="kubernetes.io/rbd" \
--from-literal=key=AQCZ96BeUgPkDhAAhxbWarZh9kTx2QbFCDM/rA== \
--namespace=default
# kubectl get secret
NAME TYPE DATA AGE
ceph-user-secret kubernetes.io/rbd 1 114s</pre>
</div>
3、配置StorageClass
<div class="cnblogs_code">
<pre># vim storageclass-ceph-rdb.yaml
kind: StorageClass
apiVersion: storage.k8s.io/v1
metadata:
name: dynamic-ceph-rdb
provisioner: ceph.com/rbd
parameters:
monitors: 192.168.0.246:6789,192.168.0.247:6789,192.168.0.248:6789
adminId: admin
adminSecretName: ceph-secret
adminSecretNamespace: kube-system
pool: kube
userId: kube
userSecretName: ceph-user-secret
fsType: ext4
imageFormat: "2"
imageFeatures: "layering"

# kubectl apply -f storageclass-ceph-rdb.yaml
storageclass.storage.k8s.io/dynamic-ceph-rdb created
# kubectl get sc
NAME PROVISIONER RECLAIMPOLICY VOLUMEBINDINGMODE ALLOWVOLUMEEXPANSION AGE
dynamic-ceph-rdb ceph.com/rbd Delete Immediate false 12s</pre>
</div>
创建 pvc测试
<div class="cnblogs_code">
<pre># 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
# kubectl get pv,pvc
NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS CLAIM STORAGECLASS REASON AGE
persistentvolume/pvc-908ec99d-5029-4c62-952f-016ca11ab08c 2Gi RWO Delete Bound default/ceph-rdb-claim dynamic-ceph-rdb 8s

NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE
persistentvolumeclaim/ceph-rdb-claim Bound pvc-908ec99d-5029-4c62-952f-016ca11ab08c 2Gi RWO dynamic-ceph-rdb 9s</pre>
</div>
创建 nginx pod 挂载测试
<div class="cnblogs_code">
<pre># 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

# kubectl get pod -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
nginx-pod1 1/1 Running 0 43s 10.244.2.3 k8s-master1 <none> <none>
# kubectl exec -ti nginx-pod1 -- /bin/sh -c 'echo this is from Ceph RBD!!! > /usr/share/nginx/html/index.html'
# curl 10.244.2.3
this is from Ceph RBD!!!</pre>
</div>
清理
<div class="cnblogs_code">
<pre>kubectl delete -f nginx-pod.yaml
kubectl delete -f ceph-rdb-pvc-test.yaml</pre>
</div>
<h3 class="md-end-block md-heading md-focus">POD使用CephFS做为持久数据卷</h3>
CephFS方式支持k8s的pv的3种访问模式ReadWriteOnce，ReadOnlyMany ，ReadWriteMany
<h5 class="md-end-block md-heading md-focus">Ceph端创建CephFS pool</h5>
1、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
<div class="cnblogs_code">
<pre>1、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

2、创建一个CephFS
ceph fs new cephfs fs_metadata fs_data

3、查看
# ceph fs ls
name: cephfs, metadata pool: fs_metadata, data pools: </pre>
</div>
<h5 class="md-end-block md-heading md-focus">部署 cephfs-provisioner</h5>
使用社区提供的cephfs-provisioner
<div class="cnblogs_code">
<pre># cat >external-storage-cephfs-provisioner.yaml<<EOF
apiVersion: v1
kind: Namespace
metadata:
name: cephfs
labels:
name: cephfs

---
apiVersion: v1
kind: ServiceAccount
metadata:
name: cephfs-provisioner
namespace: kube-system

---
apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
name: cephfs-provisioner
namespace: kube-system
rules:
- apiGroups: [""]
resources: ["secrets"]
verbs: ["create", "get", "delete"]
- apiGroups: [""]
resources: ["endpoints"]
verbs: ["get", "list", "watch", "create", "update", "patch"]

---
kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1
metadata:
name: cephfs-provisioner
namespace: kube-system
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: ["services"]
resourceNames: ["kube-dns","coredns"]
verbs: ["list", "get"]
- apiGroups: [""]
resources: ["secrets"]
verbs: ["get", "create", "delete"]
- apiGroups: ["policy"]
resourceNames: ["cephfs-provisioner"]
resources: ["podsecuritypolicies"]
verbs: ["use"]

---
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

---
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: 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: "quay.io/external_storage/cephfs-provisioner:latest"
 env:
 - name: PROVISIONER_NAME
 value: ceph.com/cephfs
 command:
 - "/usr/local/bin/cephfs-provisioner"
 args:
 - "-id=cephfs-provisioner-1"
 - "-disable-ceph-namespace-isolation=true"
 serviceAccount: cephfs-provisioner
EOF
# kubectl apply -f external-storage-cephfs-provisioner.yaml
# kubectl get pod -n kube-system |grep cephfs
cephfs-provisioner-847468fc-5k8vx 1/1 Running 0 7m39s</pre>
</div>
配置secret
<div class="cnblogs_code">
<pre>查看key 在ceph的mon或者admin节点
ceph auth get-key client.admin

创建 admin secret
# kubectl create secret generic ceph-secret --type="kubernetes.io/rbd" \
--from-literal=key=AQCBrJ9eV/U5NBAAoDlM4gV3a+KNQDBOUqVxdw== \
--namespace=kube-system

查看
# kubectl get secret ceph-secret -n kube-system -o yaml
apiVersion: v1
data:
key: QVFDQnJKOWVWL1U1TkJBQW9EbE00Z1YzYStLTlFEQk9VcVZ4ZHc9PQ==
kind: Secret
metadata:
creationTimestamp: "2020-06-08T08:17:09Z"
name: ceph-secret
namespace: kube-system
resourceVersion: "42732"
selfLink: /api/v1/namespaces/kube-system/secrets/ceph-secret
uid: efec109a-17de-4f72-afd4-d126f4d4f8d6
type: kubernetes.io/rbd</pre>
</div>
配置 StorageClass
<div class="cnblogs_code">
<pre># vim storageclass-cephfs.yaml
kind: StorageClass
apiVersion: storage.k8s.io/v1
metadata:
name: dynamic-cephfs
provisioner: ceph.com/cephfs
parameters:
monitors: 192.168.0.246:6789,192.168.0.247:6789,192.168.0.248:6789
adminId: admin
adminSecretName: ceph-secret
adminSecretNamespace: "kube-system"
claimRoot: /volumes/kubernetes

# kubectl apply -f storageclass-cephfs.yaml
storageclass.storage.k8s.io/dynamic-cephfs created
# kubectl get sc
NAME PROVISIONER RECLAIMPOLICY VOLUMEBINDINGMODE ALLOWVOLUMEEXPANSION AGE
dynamic-ceph-rdb ceph.com/rbd Delete Immediate false 59m
dynamic-cephfs ceph.com/cephfs Delete Immediate false 5s</pre>
</div>
创建pvc测试
<div class="cnblogs_code">
<pre># 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
persistentvolumeclaim/cephfs-claim created
# kubectl get pv,pvc
NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS CLAIM STORAGECLASS REASON AGE
persistentvolume/pvc-df8768d7-5111-4e14-a0cf-dd029b00469b 2Gi RWO Delete Bound default/cephfs-claim dynamic-cephfs 12s

NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE
persistentvolumeclaim/cephfs-claim Bound pvc-df8768d7-5111-4e14-a0cf-dd029b00469b 2Gi RWO dynamic-cephfs 13s</pre>
</div>
创建 nginx pod 挂载测试
<div class="cnblogs_code">
<pre># 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
# kubectl apply -f nginx-pod.yaml
# kubectl get pod -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
nginx-pod2 1/1 Running 0 37s 10.244.2.5 k8s-master1 <none> <none>
# kubectl exec -ti nginx-pod2 -- /bin/sh -c 'echo This is from CephFS!!! > /usr/share/nginx/html/index.html'
# curl 10.244.2.5
This is from CephFS!!!
###查看挂载信息
# kubectl exec -ti nginx-pod2 -- /bin/sh -c 'df -h'
Filesystem SizeUsed Avail Use% Mounted on
overlay 76G4.1G 72G 6% /
tmpfs 64M 0 64M 0% /dev
tmpfs 1.4G 01.4G 0% /sys/fs/cgroup
/dev/sda3 76G4.1G 72G 6% /etc/hosts
shm 64M 0 64M 0% /dev/shm
192.168.0.246:6789,192.168.0.247:6789,192.168.0.248:6789:/volumes/kubernetes/kubernetes/kubernetes-dynamic-pvc-e957596e-a969-11ea-8966-cec7bd638523 85G 0 85G 0% /usr/share/nginx/html
tmpfs 1.4G 12K1.4G 1% /run/secrets/kubernetes.io/serviceaccount
tmpfs 1.4G 01.4G 0% /proc/acpi
tmpfs 1.4G 01.4G 0% /proc/scsi
tmpfs 1.4G 01.4G 0% /sys/firmware</pre>
</div> 
来源：https://www.cnblogs.com/yuezhimi/p/13066663.html

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kubernetes使用ceph存储