How to Quickly Build a MySQL Master‑Slave Cluster with Docker

Container technology is becoming ubiquitous, and mastering Docker and Kubernetes is essential for backend developers. This article explains how to quickly set up a MySQL master‑slave architecture using Docker.

Environment Preparation

CentOS 7

Docker 18.09.0

MySQL 5.7

Environment Setup

1. Search for and pull the MySQL 5.7 image.

docker search mysql
docker pull mysql:5.7

2. Create a master folder and add my.cnf to enable binary logging and set a unique server‑id.

mkdir master && vi ./master/my.cnf
[mysqld]
log-bin = mysql-bin
server-id = 3310

3. Run the master container.

docker run -d -e MYSQL_ROOT_PASSWORD=123456 --name master -v $PWD/master:/etc/mysql/conf.d -p 3310:3306 mysql:5.7

Check the container status:

docker ps mysql

4. Connect to the master container.

docker exec -it master bash
mysql -uroot -p

5. Verify the master status and that binary logging is enabled.

6. Repeat steps 2‑4 for the slave container, using a different port and server‑id.

mkdir slave && vi ./slave/my.cnf
docker run -d -e MYSQL_ROOT_PASSWORD=123456 --name slave -v $PWD/slave:/etc/mysql/conf.d -p 3311:3306 mysql:5.7

7. Configure the slave to replicate from the master.

change master to master_host='localhost', master_user='root', master_password='123456', master_port=3310, master_log_file='mysql-bin.000003', master_log_pos=154, master_connect_retry=60;

8. Start replication and check its status.

start slave
show slave status

Result Verification

9. Connect to the master container and create a test database.

docker exec -it master bash
mysql -uroot -p123456
create database test;

10. Connect to the slave container and list databases to confirm the new database appears.

docker exec -it slave bash
mysql -uroot -p123456
show databases;

When both SlaveIORunning and SlaveSQLRunning show Yes, replication is successful, confirming that the Docker‑based MySQL master‑slave setup is complete.