云原生MySQLonk8s环境部署

　　一、概述
　　MySQL  是一个关系型数据库管理系统，由瑞典MySQL AB 公司开发，属于 Oracle 旗下产品。MySQL 是最流行的关系型数据库管理系统之一，在 WEB 应用方面，MySQL是最好的 RDBMS (Relational Database Management System，关系数据库管理系统) 应用软件之一。这里主要讲mysql部署在k8s上，mysql部署在k8s上的优势主要有以下几点：资源隔离 动态弹性扩缩容 环境一致性 运维方便
　　官方文档：https://docs.oracle.com/en-us/iaas/mysql-database/doc/getting-started.html
　　MySQL 原理介绍也可以参考我这篇文章：MySQL原理介绍
　　二、开始部署（一主两从）
　　1）添加源helm repo add bitnami https://charts.bitnami.com/bitnami helm pull bitnami/mysql tar -xf mysql-9.3.3.tgz2）修改配置修改 mysql/values.yaml  ...  image:   registry: myharbor.com   repository: bigdata/mysql   tag: 8.0.30-debian-11-r15  ...  architecture: replication  ...  primary:   persistence:     enabled: true     size: 10Gi     storageClass: ＂mysql-local-storage＂     # 目录需要提前在宿主机上创建     local:     - name: mysql-0       host: ＂local-168-182-110＂       path: ＂/opt/bigdata/servers/mysql/data/data1＂   service:     type: NodePort     nodePorts:       mysql: ＂30306＂  secondary:   replicaCount: 2   persistence:     enabled: true     size: 10Gi     storageClass: ＂mysql-local-storage＂     # 目录需要提前在宿主机上创建     local:     - name: mysql-1       host: ＂local-168-182-111＂       path: ＂/opt/bigdata/servers/mysql/data/data1＂     - name: mysql-2       host: ＂local-168-182-112＂       path: ＂/opt/bigdata/servers/mysql/data/data1＂   service:     type: NodePort     nodePorts:       mysql: ＂30307＂  ...  metrics:   ## @param metrics.enabled Start a side-car prometheus exporter   ##   enabled: true   image:     registry: myharbor.com     repository: bigdata/mysqld-exporter     tag: 0.14.0-debian-11-r33添加 mysql/templates/pv.yaml  {{- range .Values.primary.persistence.local }} --- apiVersion: v1 kind: PersistentVolume metadata:   name: {{ .name }}   labels:     name: {{ .name }} spec:   storageClassName: {{ $.Values.primary.persistence.storageClass }}   capacity:     storage: {{ $.Values.primary.persistence.size }}   accessModes:     - ReadWriteOnce   local:     path: {{ .path }}   nodeAffinity:     required:       nodeSelectorTerms:         - matchExpressions:             - key: kubernetes.io/hostname               operator: In               values:                 - {{ .host }} --- {{- end }}  {{- range .Values.secondary.persistence.local }} --- apiVersion: v1 kind: PersistentVolume metadata:   name: {{ .name }}   labels:     name: {{ .name }} spec:   storageClassName: {{ $.Values.secondary.persistence.storageClass }}   capacity:     storage: {{ $.Values.secondary.persistence.size }}   accessModes:     - ReadWriteOnce   local:     path: {{ .path }}   nodeAffinity:     required:       nodeSelectorTerms:         - matchExpressions:             - key: kubernetes.io/hostname               operator: In               values:                 - {{ .host }} --- {{- end }}添加 mysql/templates/storage-class.yaml  kind: StorageClass apiVersion: storage.k8s.io/v1 metadata:   name: {{ .Values.primary.persistence.storageClass }} provisioner: kubernetes.io/no-provisioner3）开始安装# 创建持久化目录 mkdir -p /opt/bigdata/servers/mysql/data/data1  # 先准备好镜像 docker pull docker.io/bitnami/mysql:8.0.30-debian-11-r15 docker tag docker.io/bitnami/mysql:8.0.30-debian-11-r15 myharbor.com/bigdata/mysql:8.0.30-debian-11-r15 docker push myharbor.com/bigdata/mysql:8.0.30-debian-11-r15  # mysqld-exporter docker pull docker.io/bitnami/mysqld-exporter:0.14.0-debian-11-r33 docker tag docker.io/bitnami/mysqld-exporter:0.14.0-debian-11-r33 myharbor.com/bigdata/mysqld-exporter:0.14.0-debian-11-r33 docker push myharbor.com/bigdata/mysqld-exporter:0.14.0-debian-11-r33  # 开始安装 helm install mysql ./mysql -n mysql --create-namespace
　　NOTES NAME: mysql LAST DEPLOYED: Mon Sep 19 23:57:18 2022 NAMESPACE: mysql STATUS: deployed REVISION: 1 TEST SUITE: None NOTES: CHART NAME: mysql CHART VERSION: 9.3.3 APP VERSION: 8.0.30  ** Please be patient while the chart is being deployed **  Tip:    Watch the deployment status using the command: kubectl get pods -w --namespace mysql  Services:    echo Primary: mysql-primary.mysql.svc.cluster.local:3306   echo Secondary: mysql-secondary.mysql.svc.cluster.local:3306  Execute the following to get the administrator credentials:    echo Username: root   MYSQL_ROOT_PASSWORD=$(kubectl get secret --namespace mysql mysql -o jsonpath=＂{.data.mysql-root-password}＂ | base64 -d)  To connect to your database:    1. Run a pod that you can use as a client:        kubectl run mysql-client --rm --tty -i --restart=＂Never＂ --image  myharbor.com/bigdata/mysql:8.0.30-debian-11-r15 --namespace mysql --env MYSQL_ROOT_PASSWORD=$MYSQL_ROOT_PASSWORD --command -- bash    2. To connect to primary service (read/write):        mysql -h mysql-primary.mysql.svc.cluster.local -uroot -p＂$MYSQL_ROOT_PASSWORD＂    3. To connect to secondary service (read-only):        mysql -h mysql-secondary.mysql.svc.cluster.local -uroot -p＂$MYSQL_ROOT_PASSWORD＂    To access the MySQL Prometheus metrics from outside the cluster execute the following commands:      kubectl port-forward --namespace mysql svc/mysql-metrics 9104:9104 &     curl http://127.0.0.1:9104/metrics
　　查看pod状态 kubectl get pods,svc -n mysql -owide
　　4）测试验证
　　【温馨提示】从库（slave）是只读的。就是简单的读写测试，还有就是pod挂了，能否正常拉起等等。这个测试验证比较简单。这里就不一步步的演示了。 5）Prometheus监控
　　Prometheus：https://prometheus.k8s.local/targets?search=mysql
　　可以通过命令查看采集数据 kubectl get --raw http://10.244.0.74:9104/metrics kubectl get --raw http://10.244.1.125:9104/metrics kubectl get --raw http://10.244.2.178:9104/metrics
　　Grafana：https://grafana.k8s.local/
　　账号： admin  ，密码通过下面命令获取kubectl get secret --namespace grafana grafana -o jsonpath=＂{.data.admin-password}＂ | base64 --decode ; echo
　　导入grafana模板，集群资源监控： 7362
　　官方模块下载地址：https://grafana.com/grafana/dashboards/
　　6）卸载helm uninstall mysql -n mysql   kubectl delete pod -n mysql `kubectl get pod -n mysql |awk ＂NR>1{print $1}＂` --force kubectl patch ns mysql -p ＂{＂metadata＂:{＂finalizers＂:null}}＂ kubectl delete ns mysql --force
　　这里只是实现了mysql 的主从，没有实现高可用，官方目前没有出mysql ok k8s高可用的实现方案，虽然网上也有高可用的实现方案，但是我们公司没真正去落地使用，所以不予评价网上的高可用的方案，有兴趣的小伙伴可以去试试，其实mysql在大数据领域一般只是作为元数据存储，主挂了，影响不是很大。目前也在研究mysql on k8s 的高可用实现方案，如果后期有mysql on k8s高可用真正落地到生产环境中使用，到时候再来分享一下。MySQL on k8s 环境部署就先这里了，有疑问的小伙伴欢迎给我留言~