Kubernetes 经过statefulset部署redis cluster集群

时间 2019-11-07

标签 kubernetes 经过 statefulset 部署 redis cluster 集群栏目 Redis 繁體版

原文原文链接

Kubernetes 经过statefulset部署redis cluster集群

做者: 张首富
时间: 2019-02-19
我的博客地址: https://www.zhangshoufu.com
QQ群: 895291458
须要有redis基础

Redis集群架构图

每一个Mater 均可以拥有多个slave.当Master掉线后,redis cluster集群会从多个Slave中选举出来一个新的Matser做为代替,而旧的Master从新上线后变成 Master 的Slave.html

部署redis集群方式的选择

Statefulset
Service&depolyment

对于redis,mysql这种有状态的服务,咱们使用statefulset方式为首选.咱们这边主要就是介绍statefulset这种方式node

ps:
statefulset 的设计原理模型:
    拓扑状态.应用的多个实例之间不是彻底对等的关系,这个应用实例的启动必须按照某些顺序启动,好比应用的
    主节点 A 要先于从节点 B 启动。而若是你把 A 和 B 两个Pod删除掉,他们再次被建立出来是也必须严格按
    照这个顺序才行,而且,新建立出来的Pod,必须和原来的Pod的网络标识同样,这样原先的访问者才能使用一样
    的方法,访问到这个新的Pod

    存储状态:应用的多个实例分别绑定了不一样的存储数据.对于这些应用实例来讲,Pod A第一次读取到的数据,和
    隔了十分钟以后再次读取到的数据,应该是同一份,哪怕在此期间Pod A被从新建立过.一个数据库应用的多个
    存储实例

statefulset 部署redis的架构图

不管是Master 仍是 slave都做为statefulset的一个副本,经过pv/pvc进行持久化,对外暴露一个service 接受客户端请求mysql

部署

安装NFS(共享存储)

由于k8s上pod是飘忽不定的,因此咱们确定须要用一个共享存储来提供存储,这样无论pod漂移到哪一个节点都能访问这个共享的数据卷.我这个地方先使用NFS来作共享存储,后期能够选择别的替换redis

yum -y install nfs-utils rpcbind
vim /etc/exports
/usr/local/kubernetes/redis/pv1 0.0.0.0/0(rw,all_squash)
/usr/local/kubernetes/redis/pv2 0.0.0.0/0(rw,all_squash)
/usr/local/kubernetes/redis/pv3 0.0.0.0/0(rw,all_squash)
/usr/local/kubernetes/redis/pv4 0.0.0.0/0(rw,all_squash)
/usr/local/kubernetes/redis/pv5 0.0.0.0/0(rw,all_squash)
/usr/local/kubernetes/redis/pv6 0.0.0.0/0(rw,all_squash)
mkdir -p /usr/local/kubernetes/redis/pv{1..6}
chmod 777 /usr/local/kubernetes/redis/pv{1..6}

后期咱们能够写成域名通配符sql

启动服务
systemctl enable nfs 
systemctl enable rpcbind
systemctl start nfs
systemctl start rpcbind

建立pv

建立6个pv 一会供pvc挂载使用docker

vim pv.yaml
apiVersion: v1
kind: PersistentVolume
metadata:
  name: nfs-pv1
spec:
  capacity:
    storage: 200M      #磁盘大小200M
  accessModes:
    - ReadWriteMany    #多客户可读写
  nfs:
    server: NFS服务器地址
    path: "/usr/local/kubernetes/redis/pv1"

---
apiVersion: v1
kind: PersistentVolume
metadata:
  name: nfs-vp2
spec:
  capacity:
    storage: 200M
  accessModes:
    - ReadWriteMany
  nfs:
    server: NFS服务器地址
    path: "/usr/local/kubernetes/redis/pv2"

---
apiVersion: v1
kind: PersistentVolume
metadata:
  name: nfs-pv3
spec:
  capacity:
    storage: 200M
  accessModes:
    - ReadWriteMany
  nfs:
    server: NFS服务器地址
    path: "/usr/local/kubernetes/redis/pv3"

---
apiVersion: v1
kind: PersistentVolume
metadata:
  name: nfs-pv4
spec:
  capacity:
    storage: 200M
  accessModes:
    - ReadWriteMany
  nfs:
    server: NFS服务器地址
    path: "/usr/local/kubernetes/redis/pv4"

---
apiVersion: v1
kind: PersistentVolume
metadata:
  name: nfs-pv5
spec:
  capacity:
    storage: 200M
  accessModes:
    - ReadWriteMany
  nfs:
    server: NFS服务器地址
    path: "/usr/local/kubernetes/redis/pv5"

---
apiVersion: v1
kind: PersistentVolume
metadata:
  name: nfs-pv6
spec:
  capacity:
    storage: 200M
  accessModes:
    - ReadWriteMany
  nfs:
    server: NFS服务器地址
    path: "/usr/local/kubernetes/redis/pv6"

字段说明:
apiversion: api版本
kind: 这个yaml是生成pv的
metadata: 元数据
spec.capacity: 进行资源限制的
spec.accessmodes: 访问模式(读写模式)
spec.nfs: 这个pv卷名是经过nfs提供的数据库

建立pvvim

kubectl create -f pv.yaml
kubectl get pv   #查看建立的pv

建立configmap,用来存放redis的配置文件

由于redis的配置文件里面可能会改变,因此咱们使用configmap这种方式给配置文件弄出来,咱们后期改的时候就不须要没改次配置文件就重新生成一个docker images包了centos

appendonly yes                      #开启Redis的AOF持久化
cluster-enabled yes                 #集群模式打开
cluster-config-file /var/lib/redis/nodes.conf  #下面说明
cluster-node-timeout 5000           #节点超时时间
dir /var/lib/redis                  #AOF持久化文件存在的位置
port 6379                           #开启的端口

cluster-conf-file: 选项设定了保存节点配置文件的路径,若是这个配置文件不存在,每一个节点在启动的时候都为他自身指定了一个新的ID存档到这个文件中,实例会一直使用同一个ID,在集群中保持一个独一无二的(Unique)名字.每一个节点都是用ID而不是IP或者端口号来记录其余节点,由于在k8s中,IP地址是不固定的,而这个独一无二的标识符(Identifier)则会在节点的整个生命周期中一直保持不变,咱们这个文件里面存放的是节点IDapi

建立名为redis-conf的Configmap：

kubectl create configmap redis-conf --from-file=redis.conf

查看:

[root@rke ~]# kubectl get cm
NAME         DATA   AGE
redis-conf   1      22h
[root@rke ~]# kubectl describe cm redis-conf
Name:         redis-conf
Namespace:    default
Labels:       <none>
Annotations:  <none>

Data
====
redis.conf:
----
appendonly yes
cluster-enabled yes
cluster-config-file /var/lib/redis/nodes.conf
cluster-node-timeout 5000
dir /var/lib/redis
port 6379

Events:  <none>

建立headless service

Headless service是StatefulSet实现稳定网络标识的基础，咱们须要提早建立。准备文件headless-service.yml以下：

apiVersion: v1
kind: Service
metadata:
  name: redis-service
  labels:
    app: redis
spec:
  ports:
  - name: redis-port
    port: 6379
  clusterIP: None
  selector:
    app: redis
    appCluster: redis-cluster

建立：

kubectl create -f headless-service.yml

查看：

[root@k8s-node1 redis]# kubectl get svc redis-service
NAME            TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)    AGE
redis-service   ClusterIP   None         <none>        6379/TCP   53s

能够看到，服务名称为redis-service，其CLUSTER-IP为None，表示这是一个“无头”服务。

建立redis集群节点

这是本文的核心内容,建立redis.yaml文件

[root@rke ~]# cat /home/docker/redis/redis.yml
apiVersion: apps/v1beta1
kind: StatefulSet
metadata:
  name: redis-app
spec:
  serviceName: "redis-service"
  replicas: 6
  template:
    metadata:
      labels:
        app: redis
        appCluster: redis-cluster
    spec:
      terminationGracePeriodSeconds: 20
      affinity:
        podAntiAffinity:
          preferredDuringSchedulingIgnoredDuringExecution:
          - weight: 100
            podAffinityTerm:
              labelSelector:
                matchExpressions:
                - key: app
                  operator: In
                  values:
                  - redis
              topologyKey: kubernetes.io/hostname
      containers:
      - name: redis
        image: "redis"
        command:
          - "redis-server"                  #redis启动命令
        args:
          - "/etc/redis/redis.conf"         #redis-server后面跟的参数,换行表明空格
          - "--protected-mode"              #容许外网访问
          - "no"
        # command: redis-server /etc/redis/redis.conf --protected-mode no
        resources:                          #资源
          requests:                         #请求的资源
            cpu: "100m"                     #m表明千分之,至关于0.1 个cpu资源
            memory: "100Mi"                 #内存100m大小
        ports:
            - name: redis
              containerPort: 6379
              protocol: "TCP"
            - name: cluster
              containerPort: 16379
              protocol: "TCP"
        volumeMounts:
          - name: "redis-conf"              #挂载configmap生成的文件
            mountPath: "/etc/redis"         #挂载到哪一个路径下
          - name: "redis-data"              #挂载持久卷的路径
            mountPath: "/var/lib/redis"
      volumes:
      - name: "redis-conf"                  #引用configMap卷
        configMap:
          name: "redis-conf"
          items:
            - key: "redis.conf"             #建立configMap指定的名称
              path: "redis.conf"            #里面的那个文件--from-file参数后面的文件
  volumeClaimTemplates:                     #进行pvc持久卷声明,
  - metadata:
      name: redis-data
    spec:
      accessModes:
      - ReadWriteMany
      resources:
        requests:
          storage: 200M

PodAntiAffinity:表示反亲和性，其决定了某个pod不能够和哪些Pod部署在同一拓扑域，能够用于将一个服务的POD分散在不一样的主机或者拓扑域中，提升服务自己的稳定性。
matchExpressions:规定了Redis Pod要尽可能不要调度到包含app为redis的Node上，也便是说已经存在Redis的Node上尽可能不要再分配Redis Pod了.
另外，根据StatefulSet的规则，咱们生成的Redis的6个Pod的hostname会被依次命名为$(statefulset名称)-$(序号)，以下图所示：

[root@rke ~]# kubectl get pods -o wide
NAME                                     READY   STATUS    RESTARTS   AGE   IP           NODE            NOMINATED NODE
redis-app-0                              1/1     Running   0          40m   10.42.2.17   192.168.1.21    <none>
redis-app-1                              1/1     Running   0          40m   10.42.0.15   192.168.1.114   <none>
redis-app-2                              1/1     Running   0          40m   10.42.1.13   192.168.1.20    <none>
redis-app-3                              1/1     Running   0          40m   10.42.2.18   192.168.1.21    <none>
redis-app-4                              1/1     Running   0          40m   10.42.0.16   192.168.1.114   <none>
redis-app-5                              1/1     Running   0          40m   10.42.1.14   192.168.1.20    <none>

如上，能够看到这些Pods在部署时是以{0..N-1}的顺序依次建立的。注意，直到redis-app-0状态启动后达到Running状态以后，redis-app-1 才开始启动。
同时，每一个Pod都会获得集群内的一个DNS域名，格式为$(podname).$(service name).$(namespace).svc.cluster.local，也便是：

redis-app-0.redis-service.default.svc.cluster.local
redis-app-1.redis-service.default.svc.cluster.local
...以此类推...

在K8S集群内部，这些Pod就能够利用该域名互相通讯。咱们可使用busybox镜像的nslookup检验这些域名:

[root@k8s-node1 ~]# kubectl run -i --tty --image busybox dns-test --restart=Never --rm /bin/sh 
If you don't see a command prompt, try pressing enter.
/ # nslookup redis-app-1.redis-service.default.svc.cluster.local
Server:     10.43.0.10
Address:    10.43.0.10:53

Name:   redis-app-1.redis-service.default.svc.cluster.local
Address: 10.42.0.15

*** Can't find redis-app-1.redis-service.default.svc.cluster.local: No answer

/ # nslookup redis-app-0.redis-service.default.svc.cluster.local
Server:     10.43.0.10
Address:    10.43.0.10:53

Name:   redis-app-0.redis-service.default.svc.cluster.local
Address: 10.42.2.17

能够看到， redis-app-0的IP为10.42.2.17。固然，若Redis Pod迁移或是重启（咱们能够手动删除掉一个Redis Pod来测试），则IP是会改变的，但Pod的域名、SRV records、A record都不会改变。
另外能够发现，咱们以前建立的pv都被成功绑定了：

[root@k8s-node1 ~]# kubectl get pv
NAME      CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS    CLAIM                            STORAGECLASS   REASON    AGE
nfs-pv1   200M       RWX            Retain           Bound     default/redis-data-redis-app-2                            1h
nfs-pv2   200M       RWX            Retain           Bound     default/redis-data-redis-app-3                            1h
nfs-pv3   200M       RWX            Retain           Bound     default/redis-data-redis-app-4                            1h
nfs-pv4   200M       RWX            Retain           Bound     default/redis-data-redis-app-5                            1h
nfs-pv5   200M       RWX            Retain           Bound     default/redis-data-redis-app-0                            1h
nfs-pv6   200M       RWX            Retain           Bound     default/redis-data-redis-app-1                            1h

初始化redis集群

建立好6个Redis Pod后，咱们还须要利用经常使用的Redis-tribe工具进行集群的初始化。

建立centos容器

因为Redis集群必须在全部节点启动后才能进行初始化，而若是将初始化逻辑写入Statefulset中，则是一件很是复杂并且低效的行为。这里，本人不得不称赞一下原项目做者的思路，值得学习。也就是说，咱们能够在K8S上建立一个额外的容器，专门用于进行K8S集群内部某些服务的管理控制。
这里，咱们专门启动一个Ubuntu的容器，能够在该容器中安装Redis-tribe，进而初始化Redis集群，执行：

kubectl run -i --tty centos --image=centos --restart=Never /bin/bash

成功后，咱们能够进入centos容器中，原项目要求执行以下命令安装基本的软件环境:

cat >> /etc/yum.repo.d/epel.repo<<'EOF'
[epel]
name=Extra Packages for Enterprise Linux 7 - $basearch
baseurl=https://mirrors.tuna.tsinghua.edu.cn/epel/7/$basearch
#mirrorlist=https://mirrors.fedoraproject.org/metalink?repo=epel-7&arch=$basearch
failovermethod=priority
enabled=1
gpgcheck=0
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL-7
EOF

初始化redis集群
首先，咱们须要安装redis-trib(redis集群命令行工具)：

yum -y install redis-trib.noarch bind-utils-9.9.4-72.el7.x86_64

而后建立一主一从的集群节点信息：

redis-trib create --replicas 1 \
`dig +short redis-app-0.redis-service.default.svc.cluster.local`:6379 \
`dig +short redis-app-1.redis-service.default.svc.cluster.local`:6379 \
`dig +short redis-app-2.redis-service.default.svc.cluster.local`:6379 \
`dig +short redis-app-3.redis-service.default.svc.cluster.local`:6379 \
`dig +short redis-app-4.redis-service.default.svc.cluster.local`:6379 \
`dig +short redis-app-5.redis-service.default.svc.cluster.local`:6379

#create: 建立一个新的集群
#--replicas 1 : 建立的集群中每一个主节点分配一个从节点,达到3主3从
#后面跟的就是redis实例所在的位置

如上，命令dig +short redis-app-0.redis-service.default.svc.cluster.local用于将Pod的域名转化为IP，这是由于redis-trib不支持域名来建立集群。
执行完成后redis-trib会打印一份预配置文件给你查看,若是没问题输入yes,redis-trib就会把这份配置文件应用到集群中

>>> Creating cluster
>>> Performing hash slots allocation on 6 nodes...
Using 3 masters:
10.42.2.17:6379
10.42.0.15:6379
10.42.1.13:6379
Adding replica 10.42.2.18:6379 to 10.42.2.17:6379
Adding replica 10.42.0.16:6379 to 10.42.0.15:6379
Adding replica 10.42.1.14:6379 to 10.42.1.13:6379
M: 4676f8913cdcd1e256db432531c80591ae6c5fc3 10.42.2.17:6379
   slots:0-5460 (5461 slots) master
M: 505f3e126882c0c5115885e54f9b361bc7e74b97 10.42.0.15:6379
   slots:5461-10922 (5462 slots) master
M: 589b4f4f908a04f56d2ab9cd6fd0fd25ea14bb8f 10.42.1.13:6379
   slots:10923-16383 (5461 slots) master
S: 366abbba45d3200329a5c6305fbcec9e29b50c80 10.42.2.18:6379
   replicates 4676f8913cdcd1e256db432531c80591ae6c5fc3
S: cee3a27cc27635da54d94f16f6375cd4acfe6c30 10.42.0.16:6379
   replicates 505f3e126882c0c5115885e54f9b361bc7e74b97
S: e9f1f704ff7c8f060d6b39e23be9cd8e55cb2e46 10.42.1.14:6379
   replicates 589b4f4f908a04f56d2ab9cd6fd0fd25ea14bb8f
Can I set the above configuration? (type 'yes' to accept):

输入yes后开始建立集群

>>> Nodes configuration updated
>>> Assign a different config epoch to each node
>>> Sending CLUSTER MEET messages to join the cluster
Waiting for the cluster to join...
>>> Performing Cluster Check (using node 10.42.2.17:6379)
M: 4676f8913cdcd1e256db432531c80591ae6c5fc3 10.42.2.17:6379
   slots:0-5460 (5461 slots) master
   1 additional replica(s)
M: 589b4f4f908a04f56d2ab9cd6fd0fd25ea14bb8f 10.42.1.13:6379@16379
   slots:10923-16383 (5461 slots) master
   1 additional replica(s)
S: e9f1f704ff7c8f060d6b39e23be9cd8e55cb2e46 10.42.1.14:6379@16379
   slots: (0 slots) slave
   replicates 589b4f4f908a04f56d2ab9cd6fd0fd25ea14bb8f
S: 366abbba45d3200329a5c6305fbcec9e29b50c80 10.42.2.18:6379@16379
   slots: (0 slots) slave
   replicates 4676f8913cdcd1e256db432531c80591ae6c5fc3
M: 505f3e126882c0c5115885e54f9b361bc7e74b97 10.42.0.15:6379@16379
   slots:5461-10922 (5462 slots) master
   1 additional replica(s)
S: cee3a27cc27635da54d94f16f6375cd4acfe6c30 10.42.0.16:6379@16379
   slots: (0 slots) slave
   replicates 505f3e126882c0c5115885e54f9b361bc7e74b97
[OK] All nodes agree about slots configuration.
>>> Check for open slots...
>>> Check slots coverage...
[OK] All 16384 slots covered.

最后一句表示集群中的16384个槽都有至少一个主节点在处理，集群运做正常.

至此，咱们的Redis集群就真正建立完毕了，连到任意一个Redis Pod中检验一下：

root@k8s-node1 ~]# kubectl exec -it redis-app-2 /bin/bash
root@redis-app-2:/data# /usr/local/bin/redis-cli -c
127.0.0.1:6379> cluster info
cluster_state:ok
cluster_slots_assigned:16384
cluster_slots_ok:16384
cluster_slots_pfail:0
cluster_slots_fail:0
cluster_known_nodes:6
cluster_size:3
cluster_current_epoch:6
cluster_my_epoch:1
cluster_stats_messages_ping_sent:186
cluster_stats_messages_pong_sent:199
cluster_stats_messages_sent:385
cluster_stats_messages_ping_received:194
cluster_stats_messages_pong_received:186
cluster_stats_messages_meet_received:5
cluster_stats_messages_received:385

127.0.0.1:6379> cluster nodes
589b4f4f908a04f56d2ab9cd6fd0fd25ea14bb8f 10.42.1.13:6379@16379 master - 0 1550555011000 3 connected 10923-16383
e9f1f704ff7c8f060d6b39e23be9cd8e55cb2e46 10.42.1.14:6379@16379 slave 589b4f4f908a04f56d2ab9cd6fd0fd25ea14bb8f 0 1550555011512 6 connected
366abbba45d3200329a5c6305fbcec9e29b50c80 10.42.2.18:6379@16379 slave 4676f8913cdcd1e256db432531c80591ae6c5fc3 0 1550555010507 4 connected
505f3e126882c0c5115885e54f9b361bc7e74b97 10.42.0.15:6379@16379 master - 0 1550555011000 2 connected 5461-10922
cee3a27cc27635da54d94f16f6375cd4acfe6c30 10.42.0.16:6379@16379 slave 505f3e126882c0c5115885e54f9b361bc7e74b97 0 1550555011713 5 connected
4676f8913cdcd1e256db432531c80591ae6c5fc3 10.42.2.17:6379@16379 myself,master - 0 1550555010000 1 connected 0-5460

另外，还能够在NFS上查看Redis挂载的数据：

[root@rke ~]# tree /usr/local/kubernetes/redis/
/usr/local/kubernetes/redis/
├── pv1
│   ├── appendonly.aof
│   ├── dump.rdb
│   └── nodes.conf
├── pv2
│   ├── appendonly.aof
│   ├── dump.rdb
│   └── nodes.conf
├── pv3
│   ├── appendonly.aof
│   ├── dump.rdb
│   └── nodes.conf
├── pv4
│   ├── appendonly.aof
│   ├── dump.rdb
│   └── nodes.conf
├── pv5
│   ├── appendonly.aof
│   ├── dump.rdb
│   └── nodes.conf
└── pv6
    ├── appendonly.aof
    ├── dump.rdb
    └── nodes.conf

6 directories, 18 files

建立用于访问service

前面咱们建立了用于实现statefulset的headless service,但该service没有cluster IP,所以不能用于外界访问.因此咱们还须要建立一个service,专用于为Redis集群提供访问和负载均衡:

piVersion: v1
kind: Service
metadata:
  name: redis-access-service
  labels:
    app: redis
spec:
  ports:
  - name: redis-port
    protocol: "TCP"
    port: 6379
    targetPort: 6379
  selector:
    app: redis
    appCluster: redis-cluster

如上，该Service名称为 redis-access-service，在K8S集群中暴露6379端口，而且会对labels name为app: redis或appCluster: redis-cluster的pod进行负载均衡。
建立后查看：

[root@rke ~]# kubectl get svc redis-access-service -o wide
NAME                   TYPE        CLUSTER-IP    EXTERNAL-IP   PORT(S)    AGE   SELECTOR
redis-access-service   ClusterIP   10.43.40.62   <none>        6379/TCP   47m   app=redis,appCluster=redis-cluster

如上,在k8s集群中,全部应用均可以经过10.43.40.62:6379来访问redis集群,固然，为了方便测试，咱们也能够为Service添加一个NodePort映射到物理机上，待测试。

测试主从切换

在K8S上搭建无缺Redis集群后，咱们最关心的就是其原有的高可用机制是否正常。这里，咱们能够任意挑选一个Master的Pod来测试集群的主从切换机制，如redis-app-2：

[root@rke ~]# kubectl get pods redis-app-2 -o wide
NAME          READY   STATUS    RESTARTS   AGE   IP           NODE           NOMINATED NODE
redis-app-2   1/1     Running   0          1h    10.42.1.13   192.168.1.20   <none>

进入redis-app-2查看：

[root@rke ~]# kubectl exec -it redis-app-2 /bin/bash
root@redis-app-2:/data# redis-cli
127.0.0.1:6379> role
1) "master"
2) (integer) 9478
3) 1) 1) "10.42.1.14"
      2) "6379"
      3) "9478"

如上能够看到，其为master，slave为10.42.1.14即redis-app-5。

接着，咱们手动删除redis-app-2：

[root@rke ~]# kubectl delete pods redis-app-2
pod "redis-app-2" deleted
[root@rke ~]# kubectl get pods redis-app-2 -o wide
NAME          READY   STATUS    RESTARTS   AGE   IP           NODE           NOMINATED NODE
redis-app-2   1/1     Running   0          19s   10.42.1.15   192.168.1.20   <none>

如上，IP改变为10.42.1.15。咱们再进入redis-app-2内部查看：

[root@rke ~]# kubectl exec -it redis-app-2 /bin/bash
root@redis-app-2:/data# redis-cli
127.0.0.1:6379> ROLE
1) "slave"
2) "10.42.1.14"
3) (integer) 6379
4) "connected"
5) (integer) 9688

如上，redis-app-2变成了slave，从属于它以前的从节点10.42.1.14即redis-app-5。

redis动态扩容

咱们如今这个集群中有6个节点三主三从,我如今添加两个pod节点,达到4主4从

添加nfs共享目录

cat >> /etc/exports <<'EOF'
/usr/local/kubernetes/redis/pv7 192.168.0.0/16(rw,all_squash)
/usr/local/kubernetes/redis/pv8 192.168.0.0/16(rw,all_squash)
EOF
systemctl restart nfs rpcbind
[root@rke ~]# mkdir /usr/local/kubernetes/redis/pv{7..8}
[root@rke ~]# chmod 777 /usr/local/kubernetes/redis/*

更新pv的yml文件,也能够本身在从新建立一个,这边选择本身新建

[root@rke redis]# cat pv_add.yml
---
apiVersion: v1
kind: PersistentVolume
metadata:
  name: nfs-pv7
spec:
  capacity:
    storage: 200M
  accessModes:
    - ReadWriteMany
  nfs:
    server: 192.168.1.253
    path: "/usr/local/kubernetes/redis/pv7"

---
apiVersion: v1
kind: PersistentVolume
metadata:
  name: nfs-pv8
spec:
  capacity:
    storage: 200M
  accessModes:
    - ReadWriteMany
  nfs:
    server: 192.168.1.253
    path: "/usr/local/kubernetes/redis/pv8"

建立查看pv:

[root@rke redis]# kubectl create -f pv_add.yml
persistentvolume/nfs-pv7 created
persistentvolume/nfs-pv8 created
[root@rke redis]# kubectl get pv
NAME          CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS      CLAIM                            STORAGECLASS   REASON   AGE
nfs-pv1       200M       RWX            Retain           Bound       default/redis-data-redis-app-1                           2h
nfs-pv2       200M       RWX            Retain           Bound       default/redis-data-redis-app-2                           2h
nfs-pv3       200M       RWX            Retain           Bound       default/redis-data-redis-app-4                           2h
nfs-pv4       200M       RWX            Retain           Bound       default/redis-data-redis-app-5                           2h
nfs-pv5       200M       RWX            Retain           Bound       default/redis-data-redis-app-0                           2h
nfs-pv6       200M       RWX            Retain           Bound       default/redis-data-redis-app-3                           2h
nfs-pv7       200M       RWX            Retain           Available                                                            7s
nfs-pv8       200M       RWX            Retain           Available                                                            7s

添加redis节点

更改redis的yml文件里面的replicas:字段,把这个字段改成8,而后升级运行

[root@rke redis]# kubectl apply -f redis.yml
Warning: kubectl apply should be used on resource created by either kubectl create --save-config or kubectl apply
statefulset.apps/redis-app configured

[root@rke redis]# kubectl get  pods
NAME                                     READY   STATUS    RESTARTS   AGE
redis-app-0                              1/1     Running   0          2h
redis-app-1                              1/1     Running   0          2h
redis-app-2                              1/1     Running   0          19m
redis-app-3                              1/1     Running   0          2h
redis-app-4                              1/1     Running   0          2h
redis-app-5                              1/1     Running   0          2h
redis-app-6                              1/1     Running   0          57s
redis-app-7                              1/1     Running   0          30s

添加集群节点

[root@rke redis]#kubectl exec -it centos /bin/bash
[root@centos /]# redis-trib add-node \
`dig +short redis-app-6.redis-service.default.svc.cluster.local`:6379 \
`dig +short redis-app-0.redis-service.default.svc.cluster.local`:6379

[root@centos /]# redis-trib add-node \
`dig +short redis-app-7.redis-service.default.svc.cluster.local`:6379 \
`dig +short redis-app-0.redis-service.default.svc.cluster.local`:6379

add-node后面跟的是新节点的信息,后面是之前集群中的任意一个节点

查看添加redis节点是否正常

[root@rke redis]# kubectl exec -it redis-app-0 bash
root@redis-app-0:/data# redis-cli
127.0.0.1:6379> cluster nodes
589b4f4f908a04f56d2ab9cd6fd0fd25ea14bb8f 10.42.1.15:6379@16379 slave e9f1f704ff7c8f060d6b39e23be9cd8e55cb2e46 0 1550564776000 7 connected
e9f1f704ff7c8f060d6b39e23be9cd8e55cb2e46 10.42.1.14:6379@16379 master - 0 1550564776000 7 connected 10923-16383
366abbba45d3200329a5c6305fbcec9e29b50c80 10.42.2.18:6379@16379 slave 4676f8913cdcd1e256db432531c80591ae6c5fc3 0 1550564777051 4 connected
505f3e126882c0c5115885e54f9b361bc7e74b97 10.42.0.15:6379@16379 master - 0 1550564776851 2 connected 5461-10922
cee3a27cc27635da54d94f16f6375cd4acfe6c30 10.42.0.16:6379@16379 slave 505f3e126882c0c5115885e54f9b361bc7e74b97 0 1550564775000 5 connected
e4697a7ba460ae2979692116b95fbe1f2c8be018 10.42.0.20:6379@16379 master - 0 1550564776549 0 connected
246c79682e6cc78b4c2c28d0e7166baf47ecb265 10.42.2.23:6379@16379 master - 0 1550564776548 8 connected
4676f8913cdcd1e256db432531c80591ae6c5fc3 10.42.2.17:6379@16379 myself,master - 0 1550564775000 1 connected 0-5460

从新分配哈希槽

redis-trib.rb reshard `dig +short redis-app-0.redis-service.default.svc.cluster.local`:6379
## 输入要移动的哈希槽
## 移动到哪一个新的master节点(ID)
## all 是从全部master节点上移动

查看对应的节点信息

127.0.0.1:6379> cluster nodes
589b4f4f908a04f56d2ab9cd6fd0fd25ea14bb8f 10.42.1.15:6379@16379 slave e9f1f704ff7c8f060d6b39e23be9cd8e55cb2e46 0 1550566162000 7 connected
e9f1f704ff7c8f060d6b39e23be9cd8e55cb2e46 10.42.1.14:6379@16379 master - 0 1550566162909 7 connected 11377-16383
366abbba45d3200329a5c6305fbcec9e29b50c80 10.42.2.18:6379@16379 slave 4676f8913cdcd1e256db432531c80591ae6c5fc3 0 1550566161600 4 connected
505f3e126882c0c5115885e54f9b361bc7e74b97 10.42.0.15:6379@16379 master - 0 1550566161902 2 connected 5917-10922
cee3a27cc27635da54d94f16f6375cd4acfe6c30 10.42.0.16:6379@16379 slave 505f3e126882c0c5115885e54f9b361bc7e74b97 0 1550566162506 5 connected
246c79682e6cc78b4c2c28d0e7166baf47ecb265 10.42.2.23:6379@16379 master - 0 1550566161600 8 connected 0-453 5461-5916 10923-11376
4676f8913cdcd1e256db432531c80591ae6c5fc3 10.42.2.17:6379@16379 myself,master - 0 1550566162000 1 connected 454-5460

对redis的相关操做能够查看:http://redisdoc.com/topic/cluster-tutorial.html#id10