MS_STATUS=`docker exec mysql-master sh -c 'export MYSQL_PWD=password; mysql -u root -e "SHOW MASTER STATUS"'`
CURRENT_LOG=`echo $MS_STATUS | awk '{print $6}'`
CURRENT_POS=`echo $MS_STATUS | awk '{print $7}'`

start_slave_stmt="CHANGE MASTER TO MASTER_HOST='mysql-master',MASTER_USER='replication_user',MASTER_PASSWORD='replicationPW',MASTER_LOG_FILE='$CURRENT_LOG',MASTER_LOG_POS=$CURRENT_POS; START SLAVE;"

start_slave_cmd='export MYSQL_PWD=password; mysql -u root -e "'

start_slave_cmd+="$start_slave_stmt"

start_slave_cmd+='"'

docker exec mysql-slave sh -c "$start_slave_cmd"

mysql-slave               | 2018-09-20T20:13:41.547886Z 11 [ERROR] [MY-010584] [Repl] Slave I/O for channel '': error connecting to master 'replication_user@mysql-master:3306' - retry-time: 60  retries: 1, Error_code: MY-002061