【全网最全最详细】K8s部署Mysql 8主从复制+读写分离

短命女 2022-11-09 12:53 886阅读 0赞

*本文使用静态存储卷实现(非存储类)，目的是比较简单易入门。*  
部署mysql5.7集群的请看[这篇文章][Link 1]

<table> 
 <thead> 
  <tr> 
   <th>软件</th> 
   <th>版本</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td>mysql</td> 
   <td>8.0.18</td> 
  </tr> 
  <tr> 
   <td>xtrabackup</td> 
   <td>8.0.9</td> 
  </tr> 
 </tbody> 
</table>

**0、制作xtrabackup镜像(`该步可跳过，可直接使用作者现成镜像`)**  
\[root@localhost ~\]$ vi Dockerfile

FROM paigeeworld/centos7:latest
    
    MAINTAINER jstang <389634070@qq.com>
    
    RUN rpm --rebuilddb && \
        yum -y install wget hostname mariadb && \
        wget https://downloads.percona.com/downloads/Percona-XtraBackup-LATEST/Percona-XtraBackup-8.0.9/binary/redhat/7/x86_64/percona-xtrabackup-80-8.0.9-1.el7.x86_64.rpm && \
    	yum -y localinstall percona-xtrabackup-80-8.0.9-1.el7.x86_64.rpm
    
    RUN rm percona-xtrabackup-80-8.0.9-1.el7.x86_64.rpm -rf
    
    EXPOSE 3307

\[root@localhost ~\]$ docker build -t jstang/xtrabackup:2.3  
\[root@localhost ~\]$ docker login  
\[root@localhost ~\]$ docker push jstang/xtrabackup:2.3  
`这个是构建镜像和把镜像上传到作者的dockerHub的jstang账户上`

**1、准备NFS服务,查看NFS服务器IP为192.168.1.11，准备三个持久化磁盘(块)**

[root@m-nfs~]# yum install nfs-utils
    [root@m-nfs~]# mkdir -p /net/mysql-0 /net/mysql-1 /net/mysql-2
    [root@m-nfs~]# ifconfig | head -2| tail -1|awk '{print $2}'
    192.168.1.11 # 查看nfs服务器IP
    [root@m-nfs~]# echo '/net/mysql-0 *(rw,no_root_squash)' >> /etc/exports
    [root@m-nfs~]# echo '/net/mysql-1 *(rw,no_root_squash)' >> /etc/exports
    [root@m-nfs~]# echo '/net/mysql-2 *(rw,no_root_squash)' >> /etc/exports
    [root@m-nfs~]# systemctl restart nfs-server
    [root@m-nfs~]# showmount -e 本机IP # 验证

**2、创建三个持久卷(mysql-0、mysql-1、mysql-2)**

apiVersion: v1
      kind: PersistentVolume
      metadata:
        name: pv-a|pv-b|pv-c
      spec:
        capacity:
          storage: 1Gi
        accessModes: 
        - ReadWriteOnce
        - ReadOnlyMany
       #persistentVolumeReclaimPolicy: Retain # 当声明被释放，pv将保留(不清理和删除)
        persistentVolumeReclaimPolicy: Recycle # 当声明被释放，空间将回收再利用
        nfs:
          server: 192.168.1.11
          path: /net/mysql-0 | /net/mysql-1 | /net/mysql-2

**3、创建configMap配置字典**

apiVersion: v1
    kind: ConfigMap
    metadata:
      name: mysql
      labels:
        app: mysql
    data:
      master.cnf: | # Apply this config only on the master. [mysqld] log-bin
      slave.cnf: | # Apply this config only on slaves. [mysqld] super-read-only

**4、部署headless服务，有状态服务都需要，让服务旗下的Pod彼此发现**

apiVersion: v1
    kind: Service
    metadata:
      name: mysql-headless
      labels:
        app: mysql
    spec:
      ports:
      - name: mysql
        port: 3306
      clusterIP: None
      selector:
        app: mysql

**5. 部署SatefulSet应用**

apiVersion: apps/v1
    kind: StatefulSet
    metadata:
      name: mysql-ss
    spec: 
      selector: 
        matchLabels: 
          app: mysql 
      serviceName: mysql-headless
      replicas: 1
      template: 
        metadata:
          labels:
            app: mysql 
        spec:
          initContainers:
          - name: init-mysql
            image: mysql:8.0.18
            command:
            - bash
            - "-c"
            - | set ex # 从hostname中获取索引，比如(mysql-1)会获取(1) [[ `hostname` =~ -([0-9]+)$ ]] || exit 1 ordinal=${BASH_REMATCH[1]} echo [mysqld] > /mnt/conf.d/server-id.cnf # 为了不让server-id=0而增加偏移量 echo server-id=$((100 + $ordinal)) >> /mnt/conf.d/server-id.cnf # 拷贝对应的文件到/mnt/conf.d/文件夹中 if [[ $ordinal -eq 0 ]]; then cp /mnt/config-map/master.cnf /mnt/conf.d/ else cp /mnt/config-map/slave.cnf /mnt/conf.d/ fi
            volumeMounts:
            - name: conf
              mountPath: /mnt/conf.d
            - name: config-map
              mountPath: /mnt/config-map
          - name: clone-mysql
            image: jstang/xtrabackup:2.3
            command:
            - bash
            - "-c"
            - | set -ex # 整体意思: # 1.如果是主mysql中的xtrabackup,就不需要克隆自己了,直接退出 # 2.如果是从mysql中的xtrabackup,先判断是否是第一次创建，因为第二次重启本地就有数据库，无需克隆。若是第一次创建(通过/var/lib/mysql/mysql文件是否存在判断),就需要克隆数据库到本地。 # 如果有数据不必克隆数据，直接退出() [[ -d /var/lib/mysql/mysql ]] && exit 0 # 如果是master数据也不必克隆 [[ `hostname` =~ -([0-9]+)$ ]] || exit 1 ordinal=${BASH_REMATCH[1]} [[ $ordinal -eq 0 ]] && exit 0 # 从序列号比自己小一的数据库克隆数据，比如mysql-2会从mysql-1处克隆数据 ncat --recv-only mysql-ss-$(($ordinal-1)).mysql-headless 3307 | xbstream -x -C /var/lib/mysql # 比较数据 xtrabackup --prepare --target-dir=/var/lib/mysql
            volumeMounts:
            - name: data
              mountPath: /var/lib/mysql
              subPath: mysql
            - name: conf
              mountPath: /etc/mysql/conf.d
          containers:
          - name: mysql
            image: mysql:8.0.18
            args: ["--default-authentication-plugin=mysql_native_password"]
            env:
            - name: MYSQL_ALLOW_EMPTY_PASSWORD
              value: "1"
            ports:
            - name: mysql
              containerPort: 3306
            volumeMounts:
            - name: data
              mountPath: /var/lib/mysql
              subPath: mysql
            - name: conf
              mountPath: /etc/mysql/conf.d
            resources:
              requests:
                cpu: 50m
                memory: 50Mi
            livenessProbe:
              exec:
                command: ["mysqladmin", "ping"]
              initialDelaySeconds: 30
              periodSeconds: 10
              timeoutSeconds: 5
            readinessProbe:
              exec:
                command: ["mysql", "-h", "127.0.0.1", "-e", "SELECT 1"]
              initialDelaySeconds: 5
              periodSeconds: 2
              timeoutSeconds: 1
          - name: xtrabackup
            image: jstang/xtrabackup:2.3
            ports:
            - name: xtrabackup
              containerPort: 3307
            command:
            - bash
            - "-c"
            - | set -ex # 确定binlog 克隆数据位置(如果binlog存在的话). cd /var/lib/mysql # 如果存在该文件，则该xrabackup是从现有的从节点克隆出来的。 if [[ -s xtrabackup_slave_info ]]; then mv xtrabackup_slave_info change_master_to.sql.in rm -f xtrabackup_binlog_info elif [[ -f xtrabackup_binlog_info ]]; then [[ `cat xtrabackup_binlog_info` =~ ^(.*?)[[:space:]]+(.*?)$ ]] || exit 1 rm xtrabackup_binlog_info echo "CHANGE MASTER TO MASTER_LOG_FILE='${BASH_REMATCH[1]}',\ MASTER_LOG_POS=${BASH_REMATCH[2]}" > change_master_to.sql.in fi if [[ -f change_master_to.sql.in ]]; then echo "Waiting for mysqld to be ready (accepting connections)" until mysql -h 127.0.0.1 -e "SELECT 1"; do sleep 1; done echo "Initializing replication from clone position" mv change_master_to.sql.in change_master_to.sql.orig mysql -h 127.0.0.1 <<EOF $(<change_master_to.sql.orig), MASTER_HOST='mysql-ss-0.mysql-headless', MASTER_USER='root', MASTER_PASSWORD='', MASTER_CONNECT_RETRY=10; START SLAVE; EOF fi exec ncat --listen --keep-open --send-only --max-conns=1 3307 -c \ "xtrabackup --backup --slave-info --stream=xbstream --host=127.0.0.1 --user=root"
            volumeMounts:
            - name: data
              mountPath: /var/lib/mysql
              subPath: mysql
            - name: conf
              mountPath: /etc/mysql/conf.d
            resources:
              requests:
                cpu: 10m
                memory: 10Mi
          volumes:
          - name: conf
            emptyDir: { }
          - name: config-map
            configMap:
              name: mysql
      volumeClaimTemplates:
      - metadata:
          name: data
        spec:    
          accessModes:
            - ReadWriteOnce
          resources:
            requests:
              storage: 0.1Gi

**5. 查看状态**  
5.1 容器运行情况  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM4OTAwNTY1_size_16_color_FFFFFF_t_70_pic_center]  
5.2 主从复制情况  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM4OTAwNTY1_size_16_color_FFFFFF_t_70_pic_center 1]

**6. 测试**  
6.1 mysql-0创建数据库

create database ui;
    create table ui.user(name varchar(255));
    insert into ui.user(name) values("jstang");

5.2 从数据库查数据(查到就成功了。)

select * from ui.user;

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM4OTAwNTY1_size_16_color_FFFFFF_t_70_pic_center 2]

[Link 1]: https://blog.csdn.net/qq_38900565/article/details/102486100
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