> 本文作者：丁辉

# 部署Mysql主从

## 基础准备

创建命名空间

```bash
kubectl create ns mysql
```

## 开始部署

### 主节点配置

1. 编辑 mysql 配置文件

   ```bash
   vi my.cnf
   ```

   内容如下

   ```bash
   [mysqld]
   pid-file        = /var/run/mysqld/mysqld.pid
   socket          = /var/run/mysqld/mysqld.sock
   datadir         = /var/lib/mysql
   secure-file-priv= NULL
   # Disabling symbolic-links is recommended to prevent assorted security risks
   symbolic-links=0
   # 服务端默认utf8编码
   character-set-server=utf8mb4
   # 默认存储引擎
   default-storage-engine=INNODB
   
   # 主从配置
   log-bin=binlog
   server-id=121
   gtid-mode=on
   enforce-gtid-consistency=on
   log-slave-updates=on
   expire_logs_days=14
   
   # Compatible with versions before 8.0
   default_authentication_plugin=mysql_native_password
   skip-host-cache
   skip-name-resolve
   
   [client]
   #设置客户端编码
   default-character-set=utf8mb4
   [mysql]
   # 设置mysql客户端默认编码
   default-character-set=utf8mb4
   
   # Custom config should go here
   !includedir /etc/mysql/conf.d/
   # Custom config should go here
   !includedir /etc/mysql/conf.d/
   ```

2. 创建 configmap

   ```bash
   kubectl create configmap mysql-master-conf --from-file=./my.cnf -n mysql
   ```

3. 编辑 Yaml

   ```bash
   vi mysql-master.yaml
   ```

   内容如下

   ```yaml
   apiVersion: apps/v1
   kind: StatefulSet
   metadata:
     namespace: mysql
     name: mysql-master
   spec:
     replicas: 1
     serviceName: mysql-master-service
     selector:
       matchLabels:
         app: mysql-master
     template:
       metadata:
         labels:
           app: mysql-master
       spec:
         containers:
         - name: mysql-master
           image: mysql:8.0
           env:
           - name: MYSQL_ROOT_PASSWORD
             value: password
           volumeMounts:
           - mountPath: /var/lib/mysql
             name: data
           - name: file
             mountPath: /etc/mysql/my.cnf
             subPath: my.cnf
           ports:
           - containerPort: 3306
             protocol: TCP
           livenessProbe:
              exec:
                command:
                  - mysql
                  - --user=root
                  - --password=password
                  - --execute=SELECT 1
              initialDelaySeconds: 10 #启动后等待10秒开始检测
              periodSeconds: 10 #每隔10秒检测一次
         nodeName: #node1
         volumes:
         - name: data
           hostPath:
             path: /opt/mysql/data
         - name: file
           configMap:
             name: mysql-master-conf
   ---
   apiVersion: v1
   kind: Service
   metadata:
     namespace: mysql
     name: mysql-master-service
   spec:
     selector:
       app: mysql-master
     ports:
     - port: 3306
       targetPort: 3306
       protocol: TCP
     type: ClusterIP
   ```

4. 部署数据库主

   ```bash
   kubectl apply -f mysql-master.yaml
   ```

### 从节点配置

1. 编辑 mysql 配置文件

   ```bash
   vi my.cnf
   ```

   内容如下

   ```bash
   [mysqld]
   pid-file        = /var/run/mysqld/mysqld.pid
   socket          = /var/run/mysqld/mysqld.sock
   datadir         = /var/lib/mysql
   secure-file-priv= NULL
   # Disabling symbolic-links is recommended to prevent assorted security risks
   symbolic-links=0
   # 服务端默认utf8编码
   character-set-server=utf8mb4
   # 默认存储引擎
   default-storage-engine=INNODB
   
   # 主从配置
   server-id=122
   gtid-mode=on
   enforce-gtid-consistency=on
   log-slave-updates=on
   expire_logs_days=14
   
   # Compatible with versions before 8.0
   default_authentication_plugin=mysql_native_password
   skip-host-cache
   skip-name-resolve
   
   [client]
   #设置客户端编码
   default-character-set=utf8mb4
   [mysql]
   # 设置mysql客户端默认编码
   default-character-set=utf8mb4
   
   # Custom config should go here
   !includedir /etc/mysql/conf.d/
   # Custom config should go here
   !includedir /etc/mysql/conf.d/
   ```

2. 创建 configmap

   ```bash
   kubectl create configmap mysql-slave-conf --from-file=./my.cnf -n mysql
   ```

3. 编辑 Yaml

   ```bash
   vi mysql-slave.yaml
   ```

   内容如下

   ```yaml
   apiVersion: apps/v1
   kind: StatefulSet
   metadata:
     namespace: mysql
     name: mysql-slave
   spec:
     replicas: 1
     serviceName: mysql-slave-service
     selector:
       matchLabels:
         app: mysql-slave
     template:
       metadata:
         labels:
           app: mysql-slave
       spec:
         containers:
         - name: mysql-slave
           image: mysql:8.0
           env:
           - name: MYSQL_ROOT_PASSWORD
             value: password
           volumeMounts:
           - mountPath: /var/lib/mysql
             name: data
           - name: file
             mountPath: /etc/mysql/my.cnf
             subPath: my.cnf
           ports:
           - containerPort: 3306
             protocol: TCP
           livenessProbe:
              exec:
                command:
                  - mysql
                  - --user=root
                  - --password=password
                  - --execute=SELECT 1
              initialDelaySeconds: 10 #启动后等待10秒开始检测
              periodSeconds: 10 #每隔10秒检测一次
         nodeName: #node2
         volumes:
         - name: data
           hostPath:
             path: /opt/mysql/data
         - name: file
           configMap:
             name: mysql-slave-conf
   ---
   apiVersion: v1
   kind: Service
   metadata:
     namespace: mysql
     name: mysql-slave-service
   spec:
     selector:
       app: mysql-slave
     ports:
     - port: 3306
       targetPort: 3306
       protocol: TCP
     type: ClusterIP
   ```

4. 部署数据库从

   ```bash
   kubectl apply -f mysql-slave.yaml
   ```

### 配置主从同步

1. 登录主节点

   ```bash
   kubectl exec -it mysql-master-0 -n mysql bash
   ```

2. 登录数据库

   ```bash
   mysql -u root -ppassword
   ```

3. 配置

   ```bash
   CREATE USER 'slave'@'%' IDENTIFIED WITH mysql_native_password BY 'slave';
   GRANT REPLICATION SLAVE ON *.* TO 'slave'@'%';
   flush privileges;
   SHOW MASTER STATUS;
   ```

4. 登录从节点

   ```bash
   kubectl exec -it mysql-slave-0 -n mysql bash
   ```

5. 登录数据库

   ```bash
   mysql -u root -ppassword
   ```

6. 配置

   ```bash
   CHANGE MASTER TO
   MASTER_HOST='IP',
   MASTER_USER='slave',
   MASTER_PASSWORD='slave',
   MASTER_PORT=3306,
   MASTER_LOG_FILE='binlog.00000*',   #列：binlog.000001
   MASTER_LOG_POS=***;   #列：868
   ```

7. 开启主从同步

   ```bash
   start slave;
   ```

8. 查看同步状态

   ```bash
   show slave status\G;
   ```

   > 查看到这两个参数为 Yes 则代表配置成功

   - Slave_IO_Running: Yes
   - Slave_SQL_Running: Yes

9. 登录主节点，创建数据库

   ```bash
   create database console;
   create database region;
   ```

   > 从节点查看仓库是否已同步