这里我使用NFS客户端进行演示，关于其他后端存储引擎可以参考官网的storageclass。文章的大部分部署参数都是以前介绍过的这里不过多说明，不明白可以先看看pv pvc以及storageclass的理论。

环境说明

192.168.0.10  k8s-01
192.168.0.11  k8s-02
192.168.0.12  k8s-03
192.168.0.13  k8s-04
 
192.168.0.14  NFS服务器

首先部署NFS-Server，在192.168.0.14服务器安装NFS服务

#这里我使用单独服务器进行演示，实际上顺便使用一台服务器安装nfs都可以 (建议和kubernetes集群分开，找单独一台机器)
[root@nfs ~]# yum install nfs-utils -y rpcbind
 
#接下来设置nfs存储目录
[root@nfs ~]# mkdir /data1/k8s-volume -p
[root@nfs ~]# chmod 755 /data1/k8s-volume/
 
#编辑nfs配置文件
[root@nfs ~]# cat /etc/exports
/data1/k8s-volume  *(rw,no_root_squash,sync)
 
#存储目录，*允许所有人连接，rw读写权限，sync文件同时写入硬盘及内存，no_root_squash 使用者root用户自动修改为普通用户
 
 
接下来启动rpcbind
[root@nfs ~]# systemctl start rpcbind
[root@nfs ~]# systemctl enable rpcbind
[root@nfs ~]# systemctl status rpcbind
● rpcbind.service - RPC bind service
   Loaded: loaded (/usr/lib/systemd/system/rpcbind.service; enabled; vendor preset: enabled)
   Active: active (running) since 二 2020-03-10 07:41:39 EDT; 19s ago
 Main PID: 4430 (rpcbind)
   CGroup: /system.slice/rpcbind.service
           └─4430 /sbin/rpcbind -w
 
3月 10 07:41:39 NFS systemd[1]: Starting RPC bind service...
3月 10 07:41:39 NFS systemd[1]: Started RPC bind service.
 
 
 
#启动NFS
[root@nfs ~]# systemctl restart nfs
[root@nfs ~]# systemctl enable nfs
[root@nfs ~]# systemctl status nfs
● nfs-server.service - NFS server and services
   Loaded: loaded (/usr/lib/systemd/system/nfs-server.service; enabled; vendor preset: disabled)
  Drop-In: /run/systemd/generator/nfs-server.service.d
           └─order-with-mounts.conf
   Active: active (exited) since 二 2020-03-10 07:42:17 EDT; 8s ago
 Main PID: 4491 (code=exited, status=0/SUCCESS)
   CGroup: /system.slice/nfs-server.service
 
3月 10 07:42:17 NFS systemd[1]: Starting NFS server and services...
3月 10 07:42:17 NFS systemd[1]: Started NFS server and services.
 
 
 
#检查rpcbind及nfs是否正常
[root@nfs ~]# rpcinfo |grep nfs
    100003    3    tcp       0.0.0.0.8.1            nfs        superuser
    100003    4    tcp       0.0.0.0.8.1            nfs        superuser
    100227    3    tcp       0.0.0.0.8.1            nfs_acl    superuser
    100003    3    udp       0.0.0.0.8.1            nfs        superuser
    100003    4    udp       0.0.0.0.8.1            nfs        superuser
    100227    3    udp       0.0.0.0.8.1            nfs_acl    superuser
    100003    3    tcp6      ::.8.1                 nfs        superuser
    100003    4    tcp6      ::.8.1                 nfs        superuser
    100227    3    tcp6      ::.8.1                 nfs_acl    superuser
    100003    3    udp6      ::.8.1                 nfs        superuser
    100003    4    udp6      ::.8.1                 nfs        superuser
    100227    3    udp6      ::.8.1                 nfs_acl    superuser
 
 
#查看nfs目录挂载权限
[root@NFS ~]# cat /var/lib/nfs/etab
/data1/k8s-volume   *(rw,sync,wdelay,hide,nocrossmnt,secure,no_root_squash,no_all_squash,no_subtree_check,secure_locks,acl,no_pnfs,anonuid=65534,anongid=65534,sec=sys,rw,secure,no_root_squash,no_all_squash)

我们nfs server端已经完毕，接下来在所有需要nfs挂载的集群节点安装以下

[root@所有节点 ~]# yum install -y nfs-utils rpcbind
 
[root@所有节点 ~]# systemctl start rpcbind
[root@所有节点 ~]# systemctl enable rpcbind
[root@所有节点 ~]# systemctl start nfs
[root@所有节点 ~]# systemctl enable nfs
Created symlink from /etc/systemd/system/multi-user.target.wants/nfs-server.service to /usr/lib/systemd/system/nfs-server.service.
 
 
##如果rpcbind启动提示Job rpcbind.service/start failed with result 'dependency'.可以执行下面的命令
 
# 查看启动文件路径find /etc/ -name '*rpcbind.socket*'
sed -i 's/ListenStream=\[::\]:111/\#ListenStream=[::]:111/g' /etc/systemd/system/sockets.target.wants/rpcbind.socket
systemctl daemon-reload
systemctl restart rpcbind.socket
systemctl start nfs

NFS安装完毕后我们可以看一下prometheus operator数据存储的目录

root@k8s-01 ~]# kubectl get pod -n monitoring prometheus-k8s-0 -o yaml
....
    volumeMounts:
    - mountPath: /etc/prometheus/config_out
      name: config-out
      readOnly: true
    - mountPath: /prometheus
      name: prometheus-k8s-db
    - mountPath: /etc/prometheus/rules/prometheus-k8s-rulefiles-0
      name: prometheus-k8s-rulefiles-0
....
  - emptyDir: {}
    name: prometheus-k8s-db
  - name: prometheus-k8s-token-6rv95

这里/prometheus目录使用的是emptyDir进行挂载，我们重建Pod之后之前的数据就没有了，由于我们的Prometheus使用Statefulset控制器进行部署的，为了保证数据一致性，这里采用storageclass来做持久化

因为我们要使用NFS作为后端存储，这里需要一个nfs-client

#现在还需要创建NFS-Client，不然prometheus pod现在是无法Running状态
 
kind: Deployment
apiVersion: apps/v1
metadata:
  name: nfs-client-provisioner
spec:
  replicas: 1
  selector:
    matchLabels:
      app: nfs-client-provisioner
  strategy:
    type: Recreate
  template:
    metadata:
      labels:
        app: nfs-client-provisioner
    spec:
      serviceAccountName: nfs-client-provisioner
      containers:
        - name: nfs-client-provisioner
          image: quay.io/external_storage/nfs-client-provisioner:latest
          volumeMounts:
            - name: nfs-client-root
              mountPath: /persistentvolumes
          env:
            - name: PROVISIONER_NAME
              value: fuseim.pri/ifs
            - name: NFS_SERVER
              value: 192.168.0.14           #nfs server 地址
            - name: NFS_PATH
              value: /data1/k8s-volume     #nfs共享目录
      volumes:
        - name: nfs-client-root
          nfs:
            server: 192.168.0.14
            path: /data1/k8s-volume

创建nfs-client rbac文件

apiVersion: v1
kind: ServiceAccount
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: ["list", "watch", "create", "update", "patch"]
  - apiGroups: [""]
    resources: ["endpoints"]
    verbs: ["create", "delete", "get", "list", "watch", "patch", "update"]
 
---
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

创建

[root@k8s-01 manifests]# kubectl apply -f nfs-rbac.yaml
serviceaccount/nfs-client-provisioner created
clusterrole.rbac.authorization.k8s.io/nfs-client-provisioner-runner created
clusterrolebinding.rbac.authorization.k8s.io/run-nfs-client-provisioner created
[root@k8s-01 manifests]# kubectl  apply  -f nfs-client.yaml
deployment.apps/nfs-client-provisioner created
 
[root@k8s-01 manifests]# kubectl get pod
NAME                                      READY   STATUS    RESTARTS   AGE
myapp-5jlc7                               1/1     Running   1          2d
myapp-cg4lq                               1/1     Running   2          3d8h
myapp-pplfn                               1/1     Running   1          3d8h
myapp-wkfqz                               1/1     Running   2          3d8h
nfs-client-provisioner-57cb5b4cfd-kbttp   1/1     Running   0          2m1s

这里创建一个StorageClass对象

[root@k8s-01 ~]# cat prometheus-storageclass.yaml
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: prometheus-data-db
provisioner: fuseim.pri/ifs
 
#创建
[root@k8s-01 ~]# kubectl apply -f  prometheus-storageclass.yaml
storageclass.storage.k8s.io/prometheus-data-db created

这里我们声明Storageclass对象，其中provisioner=fuseim.pri/ifs，则是我们集群中使用NFS作为后端存储

接下来我们在Prometheus中添加如下配置

vim kube-prometheus-master/manifests/prometheus-prometheus.yaml
...
  storage:
    volumeClaimTemplate:
      spec:
        storageClassName: prometheus-data-db
        resources:
          requests:
            storage: 100Gi
....
 
#只需要在sepc:中添加对应的信息，storageClassName为刚刚创建的名称，storage为资源对象大小

Prometheus完整配置文件如下

[root@k8s-01 manifests]# cat prometheus-prometheus.yaml
apiVersion: monitoring.coreos.com/v1
kind: Prometheus
metadata:
  labels:
    prometheus: k8s
  name: k8s
  namespace: monitoring
spec:
  alerting:
    alertmanagers:
    - name: alertmanager-main
      namespace: monitoring
      port: web
  storage:
    volumeClaimTemplate:
      spec:
        storageClassName: prometheus-data-db
        resources:
          requests:
            storage: 10Gi
  baseImage: quay.io/prometheus/prometheus
  nodeSelector:
    beta.kubernetes.io/os: linux
  replicas: 2
  resources:
    requests:
      memory: 400Mi
  ruleSelector:
    matchLabels:
      prometheus: k8s
      role: alert-rules
  securityContext:
    fsGroup: 2000
    runAsNonRoot: true
    runAsUser: 1000
  serviceAccountName: prometheus-k8s
  serviceMonitorNamespaceSelector: {}
  serviceMonitorSelector: {}
  version: v2.11.0

查看prometheus启动状态

[root@k8s-01 manifests]# kubectl get pod -n monitoring
NAME                                   READY   STATUS    RESTARTS   AGE
alertmanager-main-0                    2/2     Running   0          11h
alertmanager-main-1                    2/2     Running   15         8d
alertmanager-main-2                    2/2     Running   11         4d3h
grafana-558647b59-msz6b                1/1     Running   5          8d
kube-state-metrics-5bfc7db74d-r95r2    4/4     Running   21         8d
node-exporter-24kdw                    2/2     Running   10         8d
node-exporter-4pqhb                    2/2     Running   8          8d
node-exporter-pbjb2                    2/2     Running   8          8d
node-exporter-vcq6c                    2/2     Running   10         8d
prometheus-adapter-57c497c557-7jqq7    1/1     Running   1          2d
prometheus-k8s-0                       3/3     Running   1          2m4s
prometheus-k8s-1                       3/3     Running   1          2m3s
prometheus-operator-69bd579bf9-vq8cd   1/1     Running   1          2d

我们可以看一下pv和pvc对象资源

[root@k8s-01 manifests]# kubectl get pv -n monitoring|grep prom
pvc-5ee985bb-62cd-11ea-b6d7-000c29eeccce   10Gi       RWO            Delete           Bound    monitoring/prometheus-k8s-db-prometheus-k8s-0   prometheus-data-db             2m36s
pvc-5f0d05c0-62cd-11ea-b6d7-000c29eeccce   10Gi       RWO            Delete           Bound    monitoring/prometheus-k8s-db-prometheus-k8s-1   prometheus-data-db             2m45s
[root@k8s-01 manifests]# kubectl get pvc -n monitoring
NAME                                 STATUS   VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS         AGE
prometheus-k8s-db-prometheus-k8s-0   Bound    pvc-5ee985bb-62cd-11ea-b6d7-000c29eeccce   10Gi       RWO            prometheus-data-db   2m49s
prometheus-k8s-db-prometheus-k8s-1   Bound    pvc-5f0d05c0-62cd-11ea-b6d7-000c29eeccce   10Gi       RWO            prometheus-data-db   2m48s
[root@k8s-01 manifests]#

接下来可以测试一下Pod删除之后数据是否丢失

记录删除点

删除Pod

[root@k8s-01 manifests]# kubectl delete pod -n monitoring prometheus-k8s-0
pod "prometheus-k8s-0" deleted
[root@k8s-01 manifests]# kubectl delete pod -n monitoring prometheus-k8s-1
pod "prometheus-k8s-1" deleted

等新Pod启动查看结果

可以看到数据没有丢失