一、環境介紹
Mysql版本：5.7

Mysql master節點：
主機名：vm1
IP地址：192.168.115.5/24

Mysql slave節點：
主機名：vm2
IP地址：192.168.115.6/24

NFS節點：
主機名：vm2
IP地址：192.168.115.6/24
共享目錄：/home/mysql_master、/home/mysql_slave

二、準備mysql主從的鏡像環境
dockerfile、docker-entrypoint.sh 文件下載地址如下
https://github.com/docker-library/mysql/tree/master/5.7

準備master的鏡像
將Dockerfile, docker-entrypoint.sh復制一份用於build master鏡像文件。
在Dockerfile中添加如下內容，將mysql master的server-id設置為1

RUN sed -i ‘/\[mysqld\]/a server-id=1\nlog-bin‘ /etc/mysql/mysql.conf.d/mysqld.cnf

在docker-entrypoint.sh中添加如下內容，創建一個復制用戶並賦權限，刷新系統權限表

echo "CREATE USER ‘$MYSQL_REPLICATION_USER‘@‘%‘ IDENTIFIED BY ‘$MYSQL_REPLICATION_PASSWORD‘ ;" | "${mysql[@]}" 
echo "GRANT REPLICATION SLAVE ON *.* TO ‘$MYSQL_REPLICATION_USER‘@‘%‘ IDENTIFIED BY ‘$MYSQL_REPLICATION_PASSWORD‘ ;" | "${mysql[@]}" 
echo ‘FLUSH PRIVILEGES ;‘ | "${mysql[@]}"

準備slave的鏡像
將Dockerfile, docker-entrypoint.sh復制一份用於build slave鏡像文件。

RUN RAND="$(date +%s | rev | cut -c 1-2)$(echo ${RANDOM})" && sed -i ‘/\[mysqld\]/a server-id=‘$RAND‘\nlog-bin‘ /etc/mysql/mysql.conf.d/mysqld.cnf

在docker-entrypoint.sh中添加如下內容，配置連接master主機的host、user、password等參數，並啟動復制進程。

echo "STOP SLAVE;" | "${mysql[@]}" echo "CHANGE MASTER TO master_host=‘$MYSQL_MASTER_SERVICE_HOST‘, master_user=‘$MYSQL_REPLICATION_USER‘, master_password=‘$MYSQL_REPLICATION_PASSWORD‘ ;" | "${mysql[@]}" echo "START SLAVE;" | "${mysql[@]}"

三、開始使用修改好的dockerfile創建mysql master和slave鏡像

# cd /root/kubernetes/lnmp/mysql/Dockerfiles/Master
# docker build -t registry.fjhb.cn/mysql-master:0.1 .
# cd /root/kubernetes/lnmp/mysql/Dockerfiles/Slave
# docker build -t registry.fjhb.cn/mysql-slave:0.1 .
# docker push registry.fjhb.cn/mysql-master:0.1
# docker push registry.fjhb.cn/mysql-slave:0.1

四、創建pv和pvc，用於mysql主從存儲持久化數據
在nfs服務器上把目錄創建出來

# cd /home/
# mkdir mysql_master mysql_slave

通過yaml文件創建出兩組pv和pvc

# cd /root/kubernetes/lnmp/mysql/Storage
# cat nfs-pv-master.yaml
apiVersion: v1
kind: PersistentVolume
metadata:
  name: pv-nfs-mysql-master
spec:
  capacity:
    storage: 5Gi 
  accessModes:
  - ReadWriteOnce
  nfs: 
    path: /home/mysql_master
    server: 192.168.115.6
  persistentVolumeReclaimPolicy: Recycle 

# cat nfs-pvc-master.yaml
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: pv-nfs-mysql-master
spec:
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 5Gi
# cat nfs-pv-slave.yaml 
apiVersion: v1
kind: PersistentVolume
metadata:
  name: pv-nfs-mysql-slave
spec:
  capacity:
    storage: 6Gi 
  accessModes:
  - ReadWriteOnce
  nfs: 
    path: /home/mysql_slave
    server: 192.168.115.6
  persistentVolumeReclaimPolicy: Recycle 

# cat nfs-pvc-slave.yaml 
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: pv-nfs-mysql-slave
spec:
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 6Gi

# kubectl create -f nfs-pv-master.yaml
# kubectl create -f nfs-pvc-master.yaml
# kubectl create -f nfs-pv-slave.yaml 
# kubectl create -f nfs-pvc-slave.yaml 

五、根據yaml文件創建mysql master ReplicationController和services

# cat mysql-master-rc.yaml 
apiVersion: v1
kind: ReplicationController
metadata:
 name: mysql-master
 labels:
  name: mysql-master
spec:
  replicas: 1
  selector:
   name: mysql-master
  template:
   metadata:
    labels:
     name: mysql-master
   spec:
    containers:
    - name: mysql-master
      image: registry.fjhb.cn/mysql-master:0.1
      volumeMounts:
        - mountPath: /var/lib/mysql
          name: mysql-master-data
      ports:
      - containerPort: 3306
      env:
      - name: MYSQL_ROOT_PASSWORD
        value: "12345678"
      - name: MYSQL_REPLICATION_USER
        value: "repl"
      - name: MYSQL_REPLICAITON_PASSWORD
        value: "12345678"
    volumes:
     - name: mysql-master-data
       persistentVolumeClaim:
        claimName: pv-nfs-mysql-master

# cat mysql-master-svc.yaml 
apiVersion: v1
kind: Service
metadata:
  name: mysql-master
  labels:
   name: mysql-master
spec:
  type: NodePort
  ports:
  - port: 3306
    targetPort: 3306
    name: http
    nodePort: 30066
  selector:
    name: mysql-master

# kubectl create -f mysql-master-rc.yaml 
# kubectl create -f mysql-master-svc.yaml

使用mysql客戶端連接master測試

六、根據yaml文件創建mysql slave ReplicationController和services

# cat mysql-slave-rc.yaml 
apiVersion: v1
kind: ReplicationController
metadata:
 name: mysql-slave
 labels:
  name: mysql-slave
spec:
  replicas: 1
  selector:
   name: mysql-slave
  template:
   metadata:
    labels:
     name: mysql-slave
   spec:
    containers:
    - name: mysql-slave
      image: registry.fjhb.cn/mysql-slave:0.1
      volumeMounts:
        - mountPath: /var/lib/mysql
          name: mysql-slave-data
      ports:
      - containerPort: 3306
      env:
      - name: MYSQL_ROOT_PASSWORD
        value: "12345678"
      - name: MYSQL_REPLICATION_USER
        value: "repl"
      - name: MYSQL_REPLICAITON_PASSWORD
        value: "12345678"
    volumes:
     - name: mysql-slave-data
       persistentVolumeClaim:
        claimName: pv-nfs-mysql-slave

# cat mysql-slave-svc.yaml 
apiVersion: v1
kind: Service
metadata:
  name: mysql-slave
  labels:
   name: mysql-slave
spec:
  type: NodePort
  ports:
  - port: 3306
    targetPort: 3306
    name: http
    nodePort: 30067
  selector:
    name: mysql-slave

# kubectl create -f mysql-slave-rc.yaml 
# kubectl create -f mysql-slave-svc.yaml 

七、測試與排錯
通過mysql命令行連接slave查看復制的狀態，發現狀態是connecting

使用slave 容器連接master,發現使用root賬號可以正常連接，而使用repl賬號無法正常連接，提示access deny

修改master上的repl用戶密碼

mysql> alter user repl@‘%‘ identified by "12345678";
Query OK, 0 rows affected (0.00 sec)
mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)

完成上述修改後在slave上進行驗證一下，repl賬號可以正常連接

在slave上進行change master操作，因為創建鏡像的時候並未配置GTID參數，所以這裏不能使用MASTER_AUTO_POSITION=1參數，如果要開啟，需要去修改Dockerfile，重新生成鏡像。

mysql> stop slave;
mysql> set global sql_slave_skip_counter=1;
CHANGE MASTER TO MASTER_HOST=‘mysql-master‘, MASTER_USER=‘repl‘, MASTER_PASSWORD=‘12345678‘;
mysql> start slave;

參考文檔：
https://www.jianshu.com/p/509b65e9a4f5

在kubernetes集群中部署mysql主從