動(dòng)態(tài)存儲(chǔ)是什么
Openshift持久化存儲(chǔ)（PV）有兩種丹壕，一種是靜態(tài)的，另一種是動(dòng)態(tài)薇溃。
- 靜態(tài)存儲(chǔ)：需要管理員手動(dòng)創(chuàng)建PV菌赖，供PVC掛載調(diào)用
- 動(dòng)態(tài)存儲(chǔ)：通過(guò)一個(gè)稱作 Storage Class的對(duì)象由存儲(chǔ)系統(tǒng)根據(jù)PVC的要求自動(dòng)創(chuàng)建。
StorageClass是什么
- StorageClass是Openshfit中的一個(gè)資源對(duì)象沐序，它主要用于描述請(qǐng)求的存儲(chǔ)琉用，并提供按需傳遞動(dòng)態(tài)預(yù)配置存儲(chǔ)的參數(shù)的方法。
- StorageClass對(duì)象還可以用作控制不同級(jí)別的存儲(chǔ)和對(duì)存儲(chǔ)的訪問(wèn)的管理機(jī)制策幼。
- 有了StorageClass后辕羽，管理員無(wú)需手動(dòng)創(chuàng)建PV。Openshift的使用者在創(chuàng)建PVC時(shí)只需要指定StorageClass,會(huì)自動(dòng)按照對(duì)應(yīng)的StorageClass配置垄惧，調(diào)用對(duì)應(yīng)的Dynamic provisioning來(lái)創(chuàng)建需要的存儲(chǔ)
沒(méi)有StorageClass時(shí)代刁愿，如何使用NFS
每次需要手動(dòng)創(chuàng)建PV，一句話：麻煩到逊。
StorageClass時(shí)代來(lái)了
一次配置铣口，永久自動(dòng)，無(wú)需手動(dòng)創(chuàng)建PV觉壶，一句話：方便脑题。
NFS Provisioner原理
NFS Provisioner原理
- 新建PVC時(shí)，指定為默認(rèn)驅(qū)動(dòng)铜靶，或者指定storageclass為nfs storage
- 運(yùn)行nfs client provisioner的pod會(huì)根據(jù)配置叔遂，在共享的NFS目錄下創(chuàng)建新的文件夾，同時(shí)創(chuàng)建新的PV指向該文件夾
- 將新建的PVC與2中新建的PV關(guān)聯(lián)，完成PVC的創(chuàng)建
- 該P(yáng)VC就可以被調(diào)用的Pod掛載了已艰。
NFS StorageClass具體配置步驟
- 準(zhǔn)備NFS服務(wù)
$ yum install nfs -y
$ mkdir -p /nfsdata/share
$ chown nfsnobody:nfsnobody /nfsdata/share
$ chmod 700 /nfsdata/share
$ #開(kāi)放nfs訪問(wèn)的端口
$ iptables -A INPUT -p tcp --dport 111 -j ACCEPT
$ iptables -A INPUT -p udp --dport 111 -j ACCEPT
$ iptables -A INPUT -p tcp --dport 2049 -j ACCEPT
$ iptables -A INPUT -p udp --dport 2049 -j ACCEPT
$ # 配置NFS
$ echo "/nfsdata/share *(rw,async,no_root_squash)" >> /etc/exports
$ exportfs -a #加載共享目錄配置
$ showmount -e #查看當(dāng)前可用的共享目錄
$ # 啟動(dòng)NFS
$ systemctl restart nfs
- 確定Provisioner安裝的project（默認(rèn)為default）
如果使用default project的話
$ oc project default
如果希望將它部署在自定義的project中痊末，則新建project
$ oc new-project nfs-provisoner
- 如果安裝的project不是default的話，需要更改配置rbac.yaml,再設(shè)置權(quán)限
$ cat rbac.yaml
kind: ServiceAccount
apiVersion: v1
metadata:
name: nfs-client-provisioner
---
kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1
metadata:
name: nfs-client-provisioner-runner
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"]
---
kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1
metadata:
name: run-nfs-client-provisioner
subjects:
- kind: ServiceAccount
name: nfs-client-provisioner
namespace: default
roleRef:
kind: ClusterRole
name: nfs-client-provisioner-runner
apiGroup: rbac.authorization.k8s.io
---
kind: Role
apiVersion: rbac.authorization.k8s.io/v1
metadata:
name: leader-locking-nfs-client-provisioner
rules:
- apiGroups: [""]
resources: ["endpoints"]
verbs: ["get", "list", "watch", "create", "update", "patch"]
---
kind: RoleBinding
apiVersion: rbac.authorization.k8s.io/v1
metadata:
name: leader-locking-nfs-client-provisioner
subjects:
- kind: ServiceAccount
name: nfs-client-provisioner
# replace with namespace where provisioner is deployed
namespace: default
roleRef:
kind: Role
name: leader-locking-nfs-client-provisioner
apiGroup: rbac.authorization.k8s.io
$ NAMESPACE=`oc project -q`
$ sed -i'' "s/namespace:.*/namespace: $NAMESPACE/g" ./deploy/rbac.yaml
$ oc create -f deploy/rbac.yaml
$ oc adm policy add-scc-to-user hostmount-anyuid system:serviceaccount:$NAMESPACE:nfs-client-provisioner
- 更新deploy/deployment.yaml哩掺，設(shè)置NFS Server的配置
$ cat << EOF | oc create -f -
kind: Deployment
apiVersion: extensions/v1beta1
metadata:
name: nfs-client-provisioner
spec:
replicas: 1
strategy:
type: Recreate
template:
metadata:
labels:
app: nfs-client-provisioner
spec:
serviceAccountName: nfs-client-provisioner
containers:
- name: nfs-client-provisioner
image: docker.io/xhuaustc/nfs-client-provisioner:latest
volumeMounts:
- name: nfs-client-root
mountPath: /persistentvolumes
env:
- name: PROVISIONER_NAME
value: fuseim.pri/ifs
- name: NFS_SERVER
value: <YOUR NFS SERVER HOSTNAME>
- name: NFS_PATH
value: /nfsdata/share
volumes:
- name: nfs-client-root
nfs:
server: <YOUR NFS SERVER HOSTNAME>
path: /nfsdata/share
EOF
- 創(chuàng)建storageclass
$ cat << EOF | oc create -f -
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
name: managed-nfs-storage
annotations:
storageclass.kubernetes.io/is-default-class: "true" # 設(shè)置該storageclass為PVC創(chuàng)建時(shí)默認(rèn)使用的存儲(chǔ)機(jī)制
provisioner: fuseim.pri/ifs # 匹配deployment中的環(huán)境變量'PROVISIONER_NAME'
parameters:
archiveOnDelete: "true" # "false" 刪除PVC時(shí)不會(huì)保留數(shù)據(jù)凿叠，"true"將保留PVC數(shù)據(jù)
reclaimPolicy: Delete
EOF
NFS StorageClass使用
- 創(chuàng)建PVC
$ cat << EOF | oc create -f -
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
annotations:
volume.beta.kubernetes.io/storage-class: managed-nfs-storage
volume.beta.kubernetes.io/storage-provisioner: fuseim.pri/ifs
name: testpvc
spec:
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 1Gi
EOF
如果storageclass中設(shè)置了storageclass.kubernetes.io/is-default-class: "true"，可以更簡(jiǎn)單地創(chuàng)建PVC
$ cat << EOF | oc create -f -
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
name: hello-pvc
spec:
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 1Gi
EOF
- 查看PVC
$ oc get pv
NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS CLAIM STORAGECLASS REASON AGE
pvc-fb952566-4bed-11e9-9007-525400ad3b43 1Gi RWO Delete Bound test/hello-pvc managed-nfs-storage 5m
$ oc get pvc
hello-pvc Bound pvc-fb952566-4bed-11e9-9007-525400ad3b43 1Gi RWO managed-nfs-storage 4m
- 如果storageclass中設(shè)置了
archiveOnDelete: "true"嚼吞，在刪除PVC時(shí)盒件，會(huì)將數(shù)據(jù)目錄歸檔
$ ls /nfsdata/share
test-hello-pvc-pvc-fb952566-4bed-11e9-9007-525400ad3b43
$ oc delete pvc hello-pvc
$ ls /nfsdata/share
archived-test-hello-pvc-pvc-fb952566-4bed-11e9-9007-525400ad3b43
$ #數(shù)據(jù)目錄被改名為以archived開(kāi)頭的文件夾，同時(shí)刪除了對(duì)應(yīng)的PV和PVC
總結(jié)
有了NFS StorageClass后舱禽，創(chuàng)建存儲(chǔ)就非常簡(jiǎn)單方便了炒刁。
Openshift NFS動(dòng)態(tài)存儲(chǔ)代碼 https://github.com/kubernetes-incubator/external-storage/tree/master/nfs-client
