Docker MySQL master-slave replication

MySQL 8.0 master-slave replication with using Docker. Slave will be in super read only mode.

Run

Create 3 MySQL containers with master-slave row-based replication

This will create 3 MySQL containers with master-slave replication. The master will be running on port 20306 and the slaves will be running on port 20307 and 20308.

> [!info]
> The default password and database name could be change in env file in each database config folder. The current config is set to allow empty password.

```bash
./build.sh

Test

Make changes to master

docker exec mysql_master sh -c "export MYSQL_PWD=111; mysql -u root mydb -e 'create table code(code int); insert into code values (100), (200)'"

Read changes from slave

docker exec mysql_slave_1 sh -c "export MYSQL_PWD=111; mysql -u root mydb -e 'select * from code \G'"
docker exec mysql_slave_2 sh -c "export MYSQL_PWD=111; mysql -u root mydb -e 'select * from code \G'"

Troubleshooting

Check Logs

docker-compose logs

Check running containers

docker-compose ps

Clean data dir

sudo rm -rf ./master/data/*
sudo rm -rf ./slave-1/data/*
sudo rm -rf ./slave-2/data/*

Run command inside "mysql_master"

docker exec mysql_master sh -c 'mysql -u root -p111 -e "SHOW MASTER STATUS \G"'

Run command inside "mysql_slave"

docker exec mysql_slave_1 sh -c 'mysql -u root -p111 -e "SHOW SLAVE STATUS \G"'
docker exec mysql_slave_2 sh -c 'mysql -u root -p111 -e "SHOW SLAVE STATUS \G"'

Enter into "mysql_master"

docker exec -it mysql_master bash

Enter into "mysql_slave"

docker exec -it mysql_slave_1 bash
docker exec -it mysql_slave_2 bash