redis是一款基于BSD协议，开源的非关系型数据库（nosql数据库），作者是意大利开发者Salvatore Sanfilippo在2009年发布，使用C语言编写；redis是基于内存存储，而且是目前比较流行的键值数据库（key-value database），它提供将内存通过网络远程共享的一种服务，提供类似功能的还有memcache，但相比 memcache，redis 还提供了易扩展、高性能、具备数据持久性等功能。主要的应用场景有session共享，常用于web集群中的tomcat或PHP中多web服务器的session共享；消息队列，ELK的日志缓存，部分业务的订阅发布系统；计数器，常用于访问排行榜，商品浏览数等和次数相关的数值统计场景；缓存，常用于数据查询、电商网站商品信息、新闻内容等；相对memcache，redis支持数据的持久化，可以将内存的数据保存在磁盘中，重启redis服务或者服务器之后可以从备份文件中恢复数据到内存继续使用；

(相关资料图)

由于redis的数据（主要是redis快照）都存放在存储系统中，即便redis pod挂掉，对应数据都不会丢；因为在k8s上部署redis单机，redis pod挂了，k8s会将对应pod重建，重建时会把对应pvc挂载至pod中，加载快照，从而使得redis的数据不被pod的挂掉而丢数据；

root@k8s-master01:~/k8s-data/dockerfile/web/magedu/redis# lltotal 1784drwxr-xr-x  2 root root    4096 Jun  5 15:22 ./drwxr-xr-x 11 root root    4096 Aug  9  2022 ../-rw-r--r--  1 root root     717 Jun  5 15:20 Dockerfile-rwxr-xr-x  1 root root     235 Jun  5 15:21 build-command.sh*-rw-r--r--  1 root root 1740967 Jun 22  2021 redis-4.0.14.tar.gz-rw-r--r--  1 root root   58783 Jun 22  2021 redis.conf-rwxr-xr-x  1 root root      84 Jun  5 15:21 run_redis.sh*root@k8s-master01:~/k8s-data/dockerfile/web/magedu/redis# cat Dockerfile #Redis Image# 导入自定义centos基础镜像FROM harbor.ik8s.cc/baseimages/magedu-centos-base:7.9.2009 # 添加redis源码包至/usr/local/srcADD redis-4.0.14.tar.gz /usr/local/src# 编译安装redisRUN ln -sv /usr/local/src/redis-4.0.14 /usr/local/redis && cd /usr/local/redis && make && cp src/redis-cli /usr/sbin/ && cp src/redis-server  /usr/sbin/ && mkdir -pv /data/redis-data # 添加redis配置文件ADD redis.conf /usr/local/redis/redis.conf # 暴露redis服务端口EXPOSE 6379#ADD run_redis.sh /usr/local/redis/run_redis.sh#CMD ["/usr/local/redis/run_redis.sh"]# 添加启动脚本ADD run_redis.sh /usr/local/redis/entrypoint.sh# 启动redisENTRYPOINT ["/usr/local/redis/entrypoint.sh"]root@k8s-master01:~/k8s-data/dockerfile/web/magedu/redis# cat build-command.sh #!/bin/bashTAG=$1#docker build -t harbor.ik8s.cc/magedu/redis:${TAG} .#sleep 3#docker push  harbor.ik8s.cc/magedu/redis:${TAG}nerdctl build -t  harbor.ik8s.cc/magedu/redis:${TAG} .nerdctl push harbor.ik8s.cc/magedu/redis:${TAG}root@k8s-master01:~/k8s-data/dockerfile/web/magedu/redis# cat run_redis.sh #!/bin/bash# Redis启动命令/usr/sbin/redis-server /usr/local/redis/redis.conf# 使用tail -f 在pod内部构建守护进程tail -f  /etc/hostsroot@k8s-master01:~/k8s-data/dockerfile/web/magedu/redis# grep -v "^#\|^$" redis.conf bind 0.0.0.0protected-mode yesport 6379tcp-backlog 511timeout 0tcp-keepalive 300daemonize yessupervised nopidfile /var/run/redis_6379.pidloglevel noticelogfile ""databases 16always-show-logo yessave 900 1save 5 1save 300 10save 60 10000stop-writes-on-bgsave-error nordbcompression yesrdbchecksum yesdbfilename dump.rdbdir /data/redis-dataslave-serve-stale-data yesslave-read-only yesrepl-diskless-sync norepl-diskless-sync-delay 5repl-disable-tcp-nodelay noslave-priority 100requirepass 123456lazyfree-lazy-eviction nolazyfree-lazy-expire nolazyfree-lazy-server-del noslave-lazy-flush noappendonly noappendfilename "appendonly.aof"appendfsync everysecno-appendfsync-on-rewrite noauto-aof-rewrite-percentage 100auto-aof-rewrite-min-size 64mbaof-load-truncated yesaof-use-rdb-preamble nolua-time-limit 5000slowlog-log-slower-than 10000slowlog-max-len 128latency-monitor-threshold 0notify-keyspace-events ""hash-max-ziplist-entries 512hash-max-ziplist-value 64list-max-ziplist-size -2list-compress-depth 0set-max-intset-entries 512zset-max-ziplist-entries 128zset-max-ziplist-value 64hll-sparse-max-bytes 3000activerehashing yesclient-output-buffer-limit normal 0 0 0client-output-buffer-limit slave 256mb 64mb 60client-output-buffer-limit pubsub 32mb 8mb 60hz 10aof-rewrite-incremental-fsync yesroot@k8s-master01:~/k8s-data/dockerfile/web/magedu/redis# 

能够将redis镜像运行为容器，并且能够通过远程主机连接至redis进行数据读写，说明我们构建的reids镜像没有问题；

root@harbor:~# mkdir -pv /data/k8sdata/magedu/redis-datadir-1mkdir: created directory "/data/k8sdata/magedu/redis-datadir-1"root@harbor:~# cat /etc/exports# /etc/exports: the access control list for filesystems which may be exported#               to NFS clients.  See exports(5).## Example for NFSv2 and NFSv3:# /srv/homes       hostname1(rw,sync,no_subtree_check) hostname2(ro,sync,no_subtree_check)## Example for NFSv4:# /srv/nfs4        gss/krb5i(rw,sync,fsid=0,crossmnt,no_subtree_check)# /srv/nfs4/homes  gss/krb5i(rw,sync,no_subtree_check)#/data/k8sdata/kuboard *(rw,no_root_squash)/data/volumes *(rw,no_root_squash)/pod-vol *(rw,no_root_squash)/data/k8sdata/myserver *(rw,no_root_squash)/data/k8sdata/mysite *(rw,no_root_squash)/data/k8sdata/magedu/images *(rw,no_root_squash)/data/k8sdata/magedu/static *(rw,no_root_squash)/data/k8sdata/magedu/zookeeper-datadir-1 *(rw,no_root_squash)/data/k8sdata/magedu/zookeeper-datadir-2 *(rw,no_root_squash)/data/k8sdata/magedu/zookeeper-datadir-3 *(rw,no_root_squash)/data/k8sdata/magedu/redis-datadir-1 *(rw,no_root_squash) root@harbor:~# exportfs -avexportfs: /etc/exports [1]: Neither "subtree_check" or "no_subtree_check" specified for export "*:/data/k8sdata/kuboard".  Assuming default behaviour ("no_subtree_check").  NOTE: this default has changed since nfs-utils version 1.0.xexportfs: /etc/exports [2]: Neither "subtree_check" or "no_subtree_check" specified for export "*:/data/volumes".  Assuming default behaviour ("no_subtree_check").  NOTE: this default has changed since nfs-utils version 1.0.xexportfs: /etc/exports [3]: Neither "subtree_check" or "no_subtree_check" specified for export "*:/pod-vol".  Assuming default behaviour ("no_subtree_check").  NOTE: this default has changed since nfs-utils version 1.0.xexportfs: /etc/exports [4]: Neither "subtree_check" or "no_subtree_check" specified for export "*:/data/k8sdata/myserver".  Assuming default behaviour ("no_subtree_check").  NOTE: this default has changed since nfs-utils version 1.0.xexportfs: /etc/exports [5]: Neither "subtree_check" or "no_subtree_check" specified for export "*:/data/k8sdata/mysite".  Assuming default behaviour ("no_subtree_check").  NOTE: this default has changed since nfs-utils version 1.0.xexportfs: /etc/exports [7]: Neither "subtree_check" or "no_subtree_check" specified for export "*:/data/k8sdata/magedu/images".  Assuming default behaviour ("no_subtree_check").  NOTE: this default has changed since nfs-utils version 1.0.xexportfs: /etc/exports [8]: Neither "subtree_check" or "no_subtree_check" specified for export "*:/data/k8sdata/magedu/static".  Assuming default behaviour ("no_subtree_check").  NOTE: this default has changed since nfs-utils version 1.0.xexportfs: /etc/exports [11]: Neither "subtree_check" or "no_subtree_check" specified for export "*:/data/k8sdata/magedu/zookeeper-datadir-1".  Assuming default behaviour ("no_subtree_check").  NOTE: this default has changed since nfs-utils version 1.0.xexportfs: /etc/exports [12]: Neither "subtree_check" or "no_subtree_check" specified for export "*:/data/k8sdata/magedu/zookeeper-datadir-2".  Assuming default behaviour ("no_subtree_check").  NOTE: this default has changed since nfs-utils version 1.0.xexportfs: /etc/exports [13]: Neither "subtree_check" or "no_subtree_check" specified for export "*:/data/k8sdata/magedu/zookeeper-datadir-3".  Assuming default behaviour ("no_subtree_check").  NOTE: this default has changed since nfs-utils version 1.0.xexportfs: /etc/exports [16]: Neither "subtree_check" or "no_subtree_check" specified for export "*:/data/k8sdata/magedu/redis-datadir-1".  Assuming default behaviour ("no_subtree_check").  NOTE: this default has changed since nfs-utils version 1.0.xexporting *:/data/k8sdata/magedu/redis-datadir-1exporting *:/data/k8sdata/magedu/zookeeper-datadir-3exporting *:/data/k8sdata/magedu/zookeeper-datadir-2exporting *:/data/k8sdata/magedu/zookeeper-datadir-1exporting *:/data/k8sdata/magedu/staticexporting *:/data/k8sdata/magedu/imagesexporting *:/data/k8sdata/mysiteexporting *:/data/k8sdata/myserverexporting *:/pod-volexporting *:/data/volumesexporting *:/data/k8sdata/kuboardroot@harbor:~# 

root@k8s-master01:~/k8s-data/yaml/magedu/redis/pv# cat redis-persistentvolume.yaml     ---apiVersion: v1kind: PersistentVolumemetadata:  name: redis-datadir-pv-1spec:  capacity:    storage: 10Gi  accessModes:    - ReadWriteOnce  nfs:    path: /data/k8sdata/magedu/redis-datadir-1     server: 192.168.0.42root@k8s-master01:~/k8s-data/yaml/magedu/redis/pv# 

root@k8s-master01:~/k8s-data/yaml/magedu/redis/pv# cat redis-persistentvolumeclaim.yaml ---apiVersion: v1kind: PersistentVolumeClaimmetadata:  name: redis-datadir-pvc-1   namespace: mageduspec:  volumeName: redis-datadir-pv-1   accessModes:    - ReadWriteOnce  resources:    requests:      storage: 10Giroot@k8s-master01:~/k8s-data/yaml/magedu/redis/pv# 

root@k8s-master01:~/k8s-data/yaml/magedu/redis# cat redis.yamlkind: Deployment#apiVersion: extensions/v1beta1apiVersion: apps/v1metadata:  labels:    app: devops-redis   name: deploy-devops-redis  namespace: mageduspec:  replicas: 1   selector:    matchLabels:      app: devops-redis  template:    metadata:      labels:        app: devops-redis    spec:      containers:        - name: redis-container          image: harbor.ik8s.cc/magedu/redis:v4.0.14           imagePullPolicy: Always          volumeMounts:          - mountPath: "/data/redis-data/"            name: redis-datadir      volumes:        - name: redis-datadir          persistentVolumeClaim:            claimName: redis-datadir-pvc-1 ---kind: ServiceapiVersion: v1metadata:  labels:    app: devops-redis  name: srv-devops-redis  namespace: mageduspec:  type: NodePort  ports:  - name: http    port: 6379     targetPort: 6379    nodePort: 36379   selector:    app: devops-redis  sessionAffinity: ClientIP  sessionAffinityConfig:    clientIP:      timeoutSeconds: 10800root@k8s-master01:~/k8s-data/yaml/magedu/redis# 

上述报错说我们的服务端口超出范围，这是因为我们在初始化k8s集群时指定的服务端口范围；

编辑/etc/systemd/system/kube-apiserver.service,将其--service-node-port-range选项指定的值修改即可；其他两个master节点也需要修改哦

root@k8s-master01:~# systemctl daemon-reload                 root@k8s-master01:~# systemctl restart kube-apiserver.serviceroot@k8s-master01:~# 

再次部署redis

root@harbor:~# ll /data/k8sdata/magedu/redis-datadir-1total 12drwxr-xr-x 2 root root 4096 Jun  5 16:29 ./drwxr-xr-x 8 root root 4096 Jun  5 15:53 ../-rw-r--r-- 1 root root  116 Jun  5 16:29 dump.rdbroot@harbor:~# 

可以看到刚才我们向redis写入数据，对应redis在规定时间内发现key的变化就做了快照，因为redis数据目录时通过pv/pvc挂载的nfs，所以我们在nfs对应目录里时可以正常看到这个快照文件的；

可以看到k8s重建后的redis pod 还保留着原有pod的数据；这说明k8s重建时挂载了前一个pod的pvc;

redis cluster相比redis单机要稍微复杂一点，我们也是通过pv/pvc将redis cluster数据存放在存储系统中，不同于redis单机，redis cluster对存入的数据会做crc16计算，然后和16384做取模计算，得出一个数字，这个数字就是存入redis cluster的一个槽位；即redis cluster将16384个槽位，平均分配给集群所有master节点，每个master节点存放整个集群数据的一部分；这样一来就存在一个问题，如果master宕机，那么对应槽位的数据也就不可用，为了防止master单点故障，我们还需要对master做高可用，即专门用一个slave节点对master做备份，master宕机的情况下，对应slave会接管master继续向集群提供服务，从而实现redis cluster master的高可用；如上图所示，我们使用3主3从的redis cluster，redis0,1,2为master，那么3，4，5就对应为0，1，2的slave，负责备份各自对应的master的数据；这六个pod都是通过k8s集群的pv/pvc将数据存放在存储系统中；

root@harbor:~# mkdir -pv /data/k8sdata/magedu/redis{0,1,2,3,4,5}mkdir: created directory "/data/k8sdata/magedu/redis0"mkdir: created directory "/data/k8sdata/magedu/redis1"mkdir: created directory "/data/k8sdata/magedu/redis2"mkdir: created directory "/data/k8sdata/magedu/redis3"mkdir: created directory "/data/k8sdata/magedu/redis4"mkdir: created directory "/data/k8sdata/magedu/redis5"root@harbor:~# tail -6 /etc/exports /data/k8sdata/magedu/redis0 *(rw,no_root_squash)/data/k8sdata/magedu/redis1 *(rw,no_root_squash)/data/k8sdata/magedu/redis2 *(rw,no_root_squash)/data/k8sdata/magedu/redis3 *(rw,no_root_squash)/data/k8sdata/magedu/redis4 *(rw,no_root_squash)/data/k8sdata/magedu/redis5 *(rw,no_root_squash)root@harbor:~# exportfs  -avexportfs: /etc/exports [1]: Neither "subtree_check" or "no_subtree_check" specified for export "*:/data/k8sdata/kuboard".  Assuming default behaviour ("no_subtree_check").  NOTE: this default has changed since nfs-utils version 1.0.xexportfs: /etc/exports [2]: Neither "subtree_check" or "no_subtree_check" specified for export "*:/data/volumes".  Assuming default behaviour ("no_subtree_check").  NOTE: this default has changed since nfs-utils version 1.0.xexportfs: /etc/exports [3]: Neither "subtree_check" or "no_subtree_check" specified for export "*:/pod-vol".  Assuming default behaviour ("no_subtree_check").  NOTE: this default has changed since nfs-utils version 1.0.xexportfs: /etc/exports [4]: Neither "subtree_check" or "no_subtree_check" specified for export "*:/data/k8sdata/myserver".  Assuming default behaviour ("no_subtree_check").  NOTE: this default has changed since nfs-utils version 1.0.xexportfs: /etc/exports [5]: Neither "subtree_check" or "no_subtree_check" specified for export "*:/data/k8sdata/mysite".  Assuming default behaviour ("no_subtree_check").  NOTE: this default has changed since nfs-utils version 1.0.xexportfs: /etc/exports [7]: Neither "subtree_check" or "no_subtree_check" specified for export "*:/data/k8sdata/magedu/images".  Assuming default behaviour ("no_subtree_check").  NOTE: this default has changed since nfs-utils version 1.0.xexportfs: /etc/exports [8]: Neither "subtree_check" or "no_subtree_check" specified for export "*:/data/k8sdata/magedu/static".  Assuming default behaviour ("no_subtree_check").  NOTE: this default has changed since nfs-utils version 1.0.xexportfs: /etc/exports [11]: Neither "subtree_check" or "no_subtree_check" specified for export "*:/data/k8sdata/magedu/zookeeper-datadir-1".  Assuming default behaviour ("no_subtree_check").  NOTE: this default has changed since nfs-utils version 1.0.xexportfs: /etc/exports [12]: Neither "subtree_check" or "no_subtree_check" specified for export "*:/data/k8sdata/magedu/zookeeper-datadir-2".  Assuming default behaviour ("no_subtree_check").  NOTE: this default has changed since nfs-utils version 1.0.xexportfs: /etc/exports [13]: Neither "subtree_check" or "no_subtree_check" specified for export "*:/data/k8sdata/magedu/zookeeper-datadir-3".  Assuming default behaviour ("no_subtree_check").  NOTE: this default has changed since nfs-utils version 1.0.xexportfs: /etc/exports [16]: Neither "subtree_check" or "no_subtree_check" specified for export "*:/data/k8sdata/magedu/redis-datadir-1".  Assuming default behaviour ("no_subtree_check").  NOTE: this default has changed since nfs-utils version 1.0.xexportfs: /etc/exports [18]: Neither "subtree_check" or "no_subtree_check" specified for export "*:/data/k8sdata/magedu/redis0".  Assuming default behaviour ("no_subtree_check").  NOTE: this default has changed since nfs-utils version 1.0.xexportfs: /etc/exports [19]: Neither "subtree_check" or "no_subtree_check" specified for export "*:/data/k8sdata/magedu/redis1".  Assuming default behaviour ("no_subtree_check").  NOTE: this default has changed since nfs-utils version 1.0.xexportfs: /etc/exports [20]: Neither "subtree_check" or "no_subtree_check" specified for export "*:/data/k8sdata/magedu/redis2".  Assuming default behaviour ("no_subtree_check").  NOTE: this default has changed since nfs-utils version 1.0.xexportfs: /etc/exports [21]: Neither "subtree_check" or "no_subtree_check" specified for export "*:/data/k8sdata/magedu/redis3".  Assuming default behaviour ("no_subtree_check").  NOTE: this default has changed since nfs-utils version 1.0.xexportfs: /etc/exports [22]: Neither "subtree_check" or "no_subtree_check" specified for export "*:/data/k8sdata/magedu/redis4".  Assuming default behaviour ("no_subtree_check").  NOTE: this default has changed since nfs-utils version 1.0.xexportfs: /etc/exports [23]: Neither "subtree_check" or "no_subtree_check" specified for export "*:/data/k8sdata/magedu/redis5".  Assuming default behaviour ("no_subtree_check").  NOTE: this default has changed since nfs-utils version 1.0.xexporting *:/data/k8sdata/magedu/redis5exporting *:/data/k8sdata/magedu/redis4exporting *:/data/k8sdata/magedu/redis3exporting *:/data/k8sdata/magedu/redis2exporting *:/data/k8sdata/magedu/redis1exporting *:/data/k8sdata/magedu/redis0exporting *:/data/k8sdata/magedu/redis-datadir-1exporting *:/data/k8sdata/magedu/zookeeper-datadir-3exporting *:/data/k8sdata/magedu/zookeeper-datadir-2exporting *:/data/k8sdata/magedu/zookeeper-datadir-1exporting *:/data/k8sdata/magedu/staticexporting *:/data/k8sdata/magedu/imagesexporting *:/data/k8sdata/mysiteexporting *:/data/k8sdata/myserverexporting *:/pod-volexporting *:/data/volumesexporting *:/data/k8sdata/kuboardroot@harbor:~# 

root@k8s-master01:~/k8s-data/yaml/magedu/redis-cluster# cat pv/redis-cluster-pv.yaml apiVersion: v1kind: PersistentVolumemetadata:  name: redis-cluster-pv0spec:  capacity:    storage: 5Gi  accessModes:    - ReadWriteOnce  nfs:    server: 192.168.0.42    path: /data/k8sdata/magedu/redis0 ---apiVersion: v1kind: PersistentVolumemetadata:  name: redis-cluster-pv1spec:  capacity:    storage: 5Gi  accessModes:    - ReadWriteOnce  nfs:    server: 192.168.0.42    path: /data/k8sdata/magedu/redis1 ---apiVersion: v1kind: PersistentVolumemetadata:  name: redis-cluster-pv2spec:  capacity:    storage: 5Gi  accessModes:    - ReadWriteOnce  nfs:    server: 192.168.0.42    path: /data/k8sdata/magedu/redis2 ---apiVersion: v1kind: PersistentVolumemetadata:  name: redis-cluster-pv3spec:  capacity:    storage: 5Gi  accessModes:    - ReadWriteOnce  nfs:    server: 192.168.0.42    path: /data/k8sdata/magedu/redis3 ---apiVersion: v1kind: PersistentVolumemetadata:  name: redis-cluster-pv4spec:  capacity:    storage: 5Gi  accessModes:    - ReadWriteOnce  nfs:    server: 192.168.0.42    path: /data/k8sdata/magedu/redis4 ---apiVersion: v1kind: PersistentVolumemetadata:  name: redis-cluster-pv5spec:  capacity:    storage: 5Gi  accessModes:    - ReadWriteOnce  nfs:    server: 192.168.0.42    path: /data/k8sdata/magedu/redis5 root@k8s-master01:~/k8s-data/yaml/magedu/redis-cluster# 

root@k8s-master01:~/k8s-data/yaml/magedu/redis-cluster# cat redis.conf appendonly yescluster-enabled yescluster-config-file /var/lib/redis/nodes.confcluster-node-timeout 5000dir /var/lib/redisport 6379root@k8s-master01:~/k8s-data/yaml/magedu/redis-cluster# 

root@k8s-master01:~/k8s-data/yaml/magedu/redis-cluster# kubectl create cm redis-conf --from-file=./redis.conf -n magedu configmap/redis-conf createdroot@k8s-master01:~/k8s-data/yaml/magedu/redis-cluster# kubectl get cm -n magedu NAME               DATA   AGEkube-root-ca.crt   1      35hredis-conf         1      6sroot@k8s-master01:~/k8s-data/yaml/magedu/redis-cluster# 

root@k8s-master01:~/k8s-data/yaml/magedu/redis-cluster# kubectl describe cm redis-conf -n magedu Name:         redis-confNamespace:    mageduLabels:       Annotations:  Data====redis.conf:----appendonly yescluster-enabled yescluster-config-file /var/lib/redis/nodes.confcluster-node-timeout 5000dir /var/lib/redisport 6379BinaryData====Events:  root@k8s-master01:~/k8s-data/yaml/magedu/redis-cluster#

root@k8s-master01:~/k8s-data/yaml/magedu/redis-cluster# cat redis.yaml apiVersion: v1kind: Servicemetadata:  name: redis  namespace: magedu  labels:    app: redisspec:  selector:    app: redis    appCluster: redis-cluster  ports:  - name: redis    port: 6379  clusterIP: None  ---apiVersion: v1kind: Servicemetadata:  name: redis-access  namespace: magedu  labels:    app: redisspec:  type: NodePort  selector:    app: redis    appCluster: redis-cluster  ports:  - name: redis-access    protocol: TCP    port: 6379    targetPort: 6379    nodePort: 36379---apiVersion: apps/v1kind: StatefulSetmetadata:  name: redis  namespace: mageduspec:  serviceName: redis  replicas: 6  selector:    matchLabels:      app: redis      appCluster: redis-cluster  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:4.0.14        command:          - "redis-server"        args:          - "/etc/redis/redis.conf"          - "--protected-mode"          - "no"        resources:          requests:            cpu: "500m"            memory: "500Mi"        ports:        - containerPort: 6379          name: redis          protocol: TCP        - containerPort: 16379          name: cluster          protocol: TCP        volumeMounts:        - name: conf          mountPath: /etc/redis        - name: data          mountPath: /var/lib/redis      volumes:      - name: conf        configMap:          name: redis-conf          items:          - key: redis.conf            path: redis.conf  volumeClaimTemplates:  - metadata:      name: data      namespace: magedu    spec:      accessModes: [ "ReadWriteOnce" ]      resources:        requests:          storage: 5Giroot@k8s-master01:~/k8s-data/yaml/magedu/redis-cluster# 

上述配置清单，主要用sts控制器创建了6个pod副本，每个副本都使用configmap中的配置文件作为redis配置文件，使用pvc模板指定pod在k8s上自动关联pv，并在magedu名称空间创建pvc,即只要k8s上有空余的pv，对应pod就会在magedu这个名称空间按pvc模板信息创建pvc；当然我们可以使用存储类自动创建pvc，也可以提前创建好pvc，一般情况下使用sts控制器，我们可以使用pvc模板的方式来指定pod自动创建pvc(前提是k8s有足够的pv可用)；

应用配置清单部署redis cluster

使用sts控制器创建pod，pod名称是sts控制器的名称-id，使用pvc模板创建pvc的名称为pvc模板名称-pod名称,即pvc模板名-sts控制器名-id;

root@k8s-master01:~/k8s-data/yaml/magedu/redis-cluster# kubectl run -it ubuntu1804 --image=ubuntu:18.04 --restart=Never -n magedu bashIf you don"t see a command prompt, try pressing enter.root@ubuntu1804:/#root@ubuntu1804:/# apt update# 安装必要工具root@ubuntu1804:/# apt install python2.7 python-pip redis-tools dnsutils iputils-ping net-tools# 更新piproot@ubuntu1804:/# pip install --upgrade pip# 使用pip安装redis cluster初始化工具redis-tribroot@ubuntu1804:/# pip install redis-trib==0.5.1root@ubuntu1804:/#

root@ubuntu1804:/# redis-trib.py create \ `dig +short redis-0.redis.magedu.svc.cluster.local`:6379 \ `dig +short redis-1.redis.magedu.svc.cluster.local`:6379 \ `dig +short redis-2.redis.magedu.svc.cluster.local`:6379 

在k8s上我们使用sts创建pod，对应pod的名称是固定不变的，所以我们初始化redis 集群就直接使用redis pod名称就可以直接解析到对应pod的IP地址；在传统虚拟机或物理机上初始化redis集群，我们可用直接使用IP地址，原因是物理机或虚拟机IP地址是固定的，在k8s上pod的IP地址是不固定的；

root@ubuntu1804:/# redis-trib.py replicate \ --master-addr `dig +short redis-0.redis.magedu.svc.cluster.local`:6379 \ --slave-addr `dig +short redis-3.redis.magedu.svc.cluster.local`:6379

root@ubuntu1804:/# redis-trib.py replicate \ --master-addr `dig +short redis-1.redis.magedu.svc.cluster.local`:6379 \ --slave-addr `dig +short redis-4.redis.magedu.svc.cluster.local`:6379

root@ubuntu1804:/# redis-trib.py replicate \--master-addr `dig +short redis-2.redis.magedu.svc.cluster.local`:6379 \--slave-addr `dig +short redis-5.redis.magedu.svc.cluster.local`:6379

集群节点信息中记录了master节点id和slave id，其中slave后面会对应master的id，表示该slave备份对应master数据；

127.0.0.1:6379> info# Serverredis_version:4.0.14redis_git_sha1:00000000redis_git_dirty:0redis_build_id:165c932261a105d7redis_mode:clusteros:Linux 5.15.0-73-generic x86_64arch_bits:64multiplexing_api:epollatomicvar_api:atomic-builtingcc_version:8.3.0process_id:1run_id:aa8ef00d843b4f622374dbb643cf27cdbd4d5ba3tcp_port:6379uptime_in_seconds:4303uptime_in_days:0hz:10lru_clock:8272053executable:/data/redis-serverconfig_file:/etc/redis/redis.conf# Clientsconnected_clients:1client_longest_output_list:0client_biggest_input_buf:0blocked_clients:0# Memoryused_memory:2642336used_memory_human:2.52Mused_memory_rss:5353472used_memory_rss_human:5.11Mused_memory_peak:2682248used_memory_peak_human:2.56Mused_memory_peak_perc:98.51%used_memory_overhead:2559936used_memory_startup:1444856used_memory_dataset:82400used_memory_dataset_perc:6.88%total_system_memory:16740012032total_system_memory_human:15.59Gused_memory_lua:37888used_memory_lua_human:37.00Kmaxmemory:0maxmemory_human:0Bmaxmemory_policy:noevictionmem_fragmentation_ratio:2.03mem_allocator:jemalloc-4.0.3active_defrag_running:0lazyfree_pending_objects:0# Persistenceloading:0rdb_changes_since_last_save:0rdb_bgsave_in_progress:0rdb_last_save_time:1685992849rdb_last_bgsave_status:okrdb_last_bgsave_time_sec:0rdb_current_bgsave_time_sec:-1rdb_last_cow_size:245760aof_enabled:1aof_rewrite_in_progress:0aof_rewrite_scheduled:0aof_last_rewrite_time_sec:-1aof_current_rewrite_time_sec:-1aof_last_bgrewrite_status:okaof_last_write_status:okaof_last_cow_size:0aof_current_size:0aof_base_size:0aof_pending_rewrite:0aof_buffer_length:0aof_rewrite_buffer_length:0aof_pending_bio_fsync:0aof_delayed_fsync:0# Statstotal_connections_received:7total_commands_processed:17223instantaneous_ops_per_sec:1total_net_input_bytes:1530962total_net_output_bytes:108793instantaneous_input_kbps:0.04instantaneous_output_kbps:0.00rejected_connections:0sync_full:1sync_partial_ok:0sync_partial_err:1expired_keys:0expired_stale_perc:0.00expired_time_cap_reached_count:0evicted_keys:0keyspace_hits:0keyspace_misses:0pubsub_channels:0pubsub_patterns:0latest_fork_usec:853migrate_cached_sockets:0slave_expires_tracked_keys:0active_defrag_hits:0active_defrag_misses:0active_defrag_key_hits:0active_defrag_key_misses:0# Replicationrole:masterconnected_slaves:1slave0:ip=10.200.155.175,port=6379,state=online,offset=1120,lag=1master_replid:60381a28fee40b44c409e53eeef49215a9d3b0ffmaster_replid2:0000000000000000000000000000000000000000master_repl_offset:1120second_repl_offset:-1repl_backlog_active:1repl_backlog_size:1048576repl_backlog_first_byte_offset:1repl_backlog_histlen:1120# CPUused_cpu_sys:12.50used_cpu_user:7.51used_cpu_sys_children:0.01used_cpu_user_children:0.00# Clustercluster_enabled:1# Keyspace127.0.0.1:6379> 

手动连接redis 集群master节点进行数据读写，存在一个问题就是当我们写入的key经过crc16计算对16384取模后，对应槽位可能不在当前节点，redis它会告诉我们该key该在哪里去写；从上面的截图可用看到，现在redis cluster 是可用正常读写数据的

root@k8s-master01:~/k8s-data/yaml/magedu/redis-cluster# cat redis-client-test.py#!/usr/bin/env python#coding:utf-8#Author:Zhang ShiJie#python 2.7/3.8#pip install redis-py-clusterimport sys,timefrom rediscluster import RedisClusterdef init_redis():    startup_nodes = [        {"host": "192.168.0.34", "port": 36379},        {"host": "192.168.0.35", "port": 36379},        {"host": "192.168.0.36", "port": 36379},        {"host": "192.168.0.34", "port": 36379},        {"host": "192.168.0.35", "port": 36379},        {"host": "192.168.0.36", "port": 36379},    ]    try:        conn = RedisCluster(startup_nodes=startup_nodes,                            # 有密码要加上密码哦                            decode_responses=True, password="")        print("连接成功！！！！！1", conn)        #conn.set("key-cluster","value-cluster")        for i in range(100):            conn.set("key%s" % i, "value%s" % i)            time.sleep(0.1)            data = conn.get("key%s" % i)            print(data)        #return conn    except Exception as e:        print("connect error ", str(e))        sys.exit(1)init_redis()root@k8s-master01:~/k8s-data/yaml/magedu/redis-cluster# 

运行脚本，向redis cluster 写入数据

root@k8s-master01:~/k8s-data/yaml/magedu/redis-cluster# python redis-client-test.pyTraceback (most recent call last):  File "/root/k8s-data/yaml/magedu/redis-cluster/redis-client-test.py", line 8, in     from rediscluster import RedisClusterModuleNotFoundError: No module named "rediscluster"root@k8s-master01:~/k8s-data/yaml/magedu/redis-cluster#

这里提示没有找到rediscluster模块，解决办法就是通过pip安装redis-py-cluster模块即可；

安装redis-py-cluster模块运行脚本连接redis cluster进行数据读写连接redis pod，验证数据是否正常写入？

从上面的截图可用看到三个reids cluster master pod各自都存放了一部分key,并非全部；说明刚才我们用python脚本把数据正常写入了redis cluster;

验证在slave 节点是否可用正常读取数据？

从上面的截图可以了解到在slave节点是不可以读取数据；

到slave对应的master节点读取数据

上述验证说明了redis cluster 只有master可以读写数据，slave只是对master数据做备份，不可以在slave上读写数据；

root@k8s-node01:~# nerdctl tag redis:4.0.14 harbor.ik8s.cc/redis-cluster/redis:4.0.14

root@k8s-node01:~# nerdctl push harbor.ik8s.cc/redis-cluster/redis:4.0.14INFO[0000] pushing as a reduced-platform image (application/vnd.docker.distribution.manifest.list.v2+json, sha256:1ae9e0f790001af4b9f83a2b3d79c593c6f3e9a881b754a99527536259fb6625) WARN[0000] skipping verifying HTTPS certs for "harbor.ik8s.cc" index-sha256:1ae9e0f790001af4b9f83a2b3d79c593c6f3e9a881b754a99527536259fb6625:    done           |++++++++++++++++++++++++++++++++++++++| manifest-sha256:5bd4fe08813b057df2ae55003a75c39d80a4aea9f1a0fbc0fbd7024edf555786: done           |++++++++++++++++++++++++++++++++++++++| config-sha256:191c4017dcdd3370f871a4c6e7e1d55c7d9abed2bebf3005fb3e7d12161262b8:   done           |++++++++++++++++++++++++++++++++++++++| elapsed: 1.4 s                                                                    total:  8.5 Ki (6.1 KiB/s)                                       root@k8s-node01:~# 

修改镜像为本地harbor镜像和拉取策略是方便我们测试redis cluster的高可用；

root@k8s-master01:~/k8s-data/yaml/magedu/redis-cluster# kubectl apply -f redis.yamlservice/redis unchangedservice/redis-access unchangedstatefulset.apps/redis configuredroot@k8s-master01:~/k8s-data/yaml/magedu/redis-cluster# 

这里相当于给redis cluster更新，他们之间的集群关系还存在，因为集群关系配置都保存在远端存储之上；

不同于之前，这里rdis-0变成了slave ,redis-3变成了master；从上面的截图我们也发现，在k8s上部署redis cluster pod重建以后（IP地址发生变化），对应集群关系不会发生变化；对应master和salve一对关系始终只是再对应的master和salve两个pod中切换，这其实就是高可用；

root@harbor:~# systemctl stop harbor

可用看到我们把redis-3删除（相当于master宕机）以后，对应slave提升为master了；

再次删除redis-3以后，对应pod正常被重建，并处于running状态；

可以看到redis-3恢复以后，对应自动加入集群成为redis-0的slave;

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