全球看點：k8s實戰案例之部署redis單機和redis cluster
發布時間：2023-06-07 07:45:25
文章來源：博客園
redis是一款基于BSD協議，開源的非關系型數據庫（nosql數據庫），作者
1、在k8s上部署redis單機1.1、redis簡介
redis是一款基于BSD協議，開源的非關系型數據庫（nosql數據庫），作者是意大利開發者Salvatore Sanfilippo在2009年發布，使用C語言編寫；redis是基于內存存儲，而且是目前比較流行的鍵值數據庫（key-value database），它提供將內存通過網絡遠程共享的一種服務，提供類似功能的還有memcache，但相比 memcache，redis 還提供了易擴展、高性能、具備數據持久性等功能。主要的應用場景有session共享，常用于web集群中的tomcat或PHP中多web服務器的session共享；消息隊列，ELK的日志緩存，部分業務的訂閱發布系統；計數器，常用于訪問排行榜，商品瀏覽數等和次數相關的數值統計場景；緩存，常用于數據查詢、電商網站商品信息、新聞內容等；相對memcache，redis支持數據的持久化，可以將內存的數據保存在磁盤中，重啟redis服務或者服務器之后可以從備份文件中恢復數據到內存繼續使用；
(資料圖片僅供參考)
1.3、構建redis鏡像由于redis的數據（主要是redis快照）都存放在存儲系統中，即便redis pod掛掉，對應數據都不會丟；因為在k8s上部署redis單機，redis pod掛了，k8s會將對應pod重建，重建時會把對應pvc掛載至pod中，加載快照，從而使得redis的數據不被pod的掛掉而丟數據；
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# 導入自定義centos基礎鏡像FROM harbor.ik8s.cc/baseimages/magedu-centos-base:7.9.2009 # 添加redis源碼包至/usr/local/srcADD redis-4.0.14.tar.gz /usr/local/src# 編譯安裝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服務端口EXPOSE 6379#ADD run_redis.sh /usr/local/redis/run_redis.sh#CMD ["/usr/local/redis/run_redis.sh"]# 添加啟動腳本ADD run_redis.sh /usr/local/redis/entrypoint.sh# 啟動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:${TAG}root@k8s-master01:~/k8s-data/dockerfile/web/magedu/redis# cat run_redis.sh #!/bin/bash# Redis啟動命令/usr/sbin/redis-server /usr/local/redis/redis.conf# 使用tail -f 在pod內部構建守護進程tail -f /etc/hostsroot@k8s-master01:~/k8s-data/dockerfile/web/magedu/redis# grep -v "^#\|^$" 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# 1.5、創建PV和PVC1.5.1、在nfs服務器上準備redis數據存儲目錄能夠將redis鏡像運行為容器，并且能夠通過遠程主機連接至redis進行數據讀寫，說明我們構建的reids鏡像沒有問題；
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# 1.6.1、修改nodeport端口范圍上述報錯說我們的服務端口超出范圍，這是因為我們在初始化k8s集群時指定的服務端口范圍；
1.6.2、重載kube-apiserver.service,重啟kube-apiserver編輯/etc/systemd/system/kube-apiserver.service,將其--service-node-port-range選項指定的值修改即可；其他兩個master節點也需要修改哦
root@k8s-master01:~# systemctl daemon-reload root@k8s-master01:~# systemctl restart kube-apiserver.serviceroot@k8s-master01:~# 再次部署redis
1.7、驗證redis數據讀寫1.7.1、連接k8s任意節點的36376端口，測試redis讀寫數據1.8、驗證redis pod 重建對應數據是否丟失？1.8.1、查看redis快照文件是否存儲到存儲上呢？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:~# 1.8.2、刪除redis pod 等待k8s重建redis pod1.8.3、驗證重建后的redis pod數據可以看到剛才我們向redis寫入數據，對應redis在規定時間內發現key的變化就做了快照，因為redis數據目錄時通過pv/pvc掛載的nfs，所以我們在nfs對應目錄里時可以正常看到這個快照文件的；
2、在k8s上部署redis集群2.1、PV/PVC及Redis Cluster-StatefulSet可以看到k8s重建后的redis pod 還保留著原有pod的數據；這說明k8s重建時掛載了前一個pod的pvc;
2.2、創建PV2.2.1、在nfs上準備redis cluster 數據目錄redis cluster相比redis單機要稍微復雜一點，我們也是通過pv/pvc將redis cluster數據存放在存儲系統中，不同于redis單機，redis cluster對存入的數據會做crc16計算，然后和16384做取模計算，得出一個數字，這個數字就是存入redis cluster的一個槽位；即redis cluster將16384個槽位，平均分配給集群所有master節點，每個master節點存放整個集群數據的一部分；這樣一來就存在一個問題，如果master宕機，那么對應槽位的數據也就不可用，為了防止master單點故障，我們還需要對master做高可用，即專門用一個slave節點對master做備份，master宕機的情況下，對應slave會接管master繼續向集群提供服務，從而實現redis cluster master的高可用；如上圖所示，我們使用3主3從的redis cluster，redis0,1,2為master，那么3，4，5就對應為0，1，2的slave，負責備份各自對應的master的數據；這六個pod都是通過k8s集群的pv/pvc將數據存放在存儲系統中；
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# 上述配置清單，主要用sts控制器創建了6個pod副本，每個副本都使用configmap中的配置文件作為redis配置文件，使用pvc模板指定pod在k8s上自動關聯pv，并在magedu名稱空間創建pvc,即只要k8s上有空余的pv，對應pod就會在magedu這個名稱空間按pvc模板信息創建pvc；當然我們可以使用存儲類自動創建pvc，也可以提前創建好pvc，一般情況下使用sts控制器，我們可以使用pvc模板的方式來指定pod自動創建pvc(前提是k8s有足夠的pv可用)；
應用配置清單部署redis cluster
2.4、初始化redis cluster2.4.1、在k8s上創建臨時容器,安裝redis cluster 初始化工具使用sts控制器創建pod，pod名稱是sts控制器的名稱-id，使用pvc模板創建pvc的名稱為pvc模板名稱-pod名稱,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# 安裝必要工具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安裝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 2.4.3、給master指定slave給redis-0指定slave為 redis-3在k8s上我們使用sts創建pod，對應pod的名稱是固定不變的，所以我們初始化redis 集群就直接使用redis pod名稱就可以直接解析到對應pod的IP地址；在傳統虛擬機或物理機上初始化redis集群，我們可用直接使用IP地址，原因是物理機或虛擬機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`:6379root@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`:6379root@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`:63792.5.3、查看當前節點信息集群節點信息中記錄了master節點id和slave id，其中slave后面會對應master的id，表示該slave備份對應master數據；
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> 2.5.4.2、使用python腳本連接redis cluster 進行數據讀寫手動連接redis 集群master節點進行數據讀寫，存在一個問題就是當我們寫入的key經過crc16計算對16384取模后，對應槽位可能不在當前節點，redis它會告訴我們該key該在哪里去寫；從上面的截圖可用看到，現在redis cluster 是可用正常讀寫數據的
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, # 有密碼要加上密碼哦 decode_responses=True, password="") print("連接成功！！！！！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# 運行腳本，向redis cluster 寫入數據
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# 這里提示沒有找到rediscluster模塊，解決辦法就是通過pip安裝redis-py-cluster模塊即可；
安裝redis-py-cluster模塊運行腳本連接redis cluster進行數據讀寫連接redis pod，驗證數據是否正常寫入？
從上面的截圖可用看到三個reids cluster master pod各自都存放了一部分key,并非全部；說明剛才我們用python腳本把數據正常寫入了redis cluster;
驗證在slave 節點是否可用正常讀取數據？
從上面的截圖可以了解到在slave節點是不可以讀取數據；
到slave對應的master節點讀取數據
2.6、驗證驗證redis cluster高可用2.6.1、在k8s node節點將redis:4.0.14鏡像上傳至本地harbor修改鏡像tag上述驗證說明了redis cluster 只有master可以讀寫數據，slave只是對master數據做備份，不可以在slave上讀寫數據；
root@k8s-node01:~# nerdctl tag redis:4.0.14 harbor.ik8s.cc/redis-cluster/redis:4.0.14root@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:~# 2.6.3、重新apply redis cluster部署清單修改鏡像為本地harbor鏡像和拉取策略是方便我們測試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# 驗證pod是否都正常running?驗證集群狀態和集群關系這里相當于給redis cluster更新，他們之間的集群關系還存在，因為集群關系配置都保存在遠端存儲之上；
2.6.4、停掉本地harbor，刪除redis master pod，看看對應slave是否會提升為master？停止harbor服務不同于之前，這里rdis-0變成了slave ,redis-3變成了master；從上面的截圖我們也發現，在k8s上部署redis cluster pod重建以后（IP地址發生變化），對應集群關系不會發生變化；對應master和salve一對關系始終只是再對應的master和salve兩個pod中切換，這其實就是高可用；
root@harbor:~# systemctl stop harbor2.6.5、恢復harbor服務，看看對應redis-3恢復會議后是否還是redis-0的slave呢？恢復harbor服務驗證redis-3pod是否恢復？可用看到我們把redis-3刪除（相當于master宕機）以后，對應slave提升為master了；
驗證redis-3的主從關系、再次刪除redis-3以后，對應pod正常被重建，并處于running狀態；
可以看到redis-3恢復以后，對應自動加入集群成為redis-0的slave;
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