docker中的mysql主从复制

binghai03

　　源码地址：https://github.com/twang2218/mysql-replica
　　

　　node: 脚本及yml均来自大桥下的蜗牛。
　　

　　dockerfile:
　　---------------------------------------------------------------------------
　　FROM mysql:5.7
　　MAINTAINER Tao Wang <twang2218@gmail.com>
　　COPY replica.sh /docker-entrypoint-initdb.d/
　　----------------------------------------------------------------------------
　　replica.sh
　　-----------------------------------------
　　(官网dockerfile并没什么难点，反而起到重要作用的是entrypoint.sh脚本，此初始化主从复制的脚本也是参考entrypoint.sh脚本。）
　　-----------------------------------------------------------------------------
　　#!/bin/bash
　　

　　# Most of the code are copied from ioggstream's PR, docker-library/mysql#43:
　　# <https://github.com/docker-library/mysql/pull/43/files>
　　#
　　# Supported environment variables for this replica.sh:
　　#  - MYSQL_REPLICA_USER: create the given user on the intended master host
　　#  - MYSQL_REPLICA_PASS
　　#  - MYSQL_MASTER_SERVER: change master on this location on the intended slave
　　#  - MYSQL_MASTER_PORT: optional, by default 3306
　　#  - MYSQL_MASTER_WAIT_TIME: seconds to wait for the master to come up
　　

　　#
　　# A replication user (actually created on both master and slaves)
　　#
　　if [ "$MYSQL_REPLICA_USER" ]; then
　　if [ -z "$MYSQL_REPLICA_PASS" ]; then
　　echo >&2 'error: MYSQL_REPLICA_USER set, but MYSQL_REPLICA_PASS not set'
　　exit 1
　　fi
　　echo "CREATE USER '$MYSQL_REPLICA_USER'@'%' IDENTIFIED BY '$MYSQL_REPLICA_PASS'; " | "${mysql[@]}"
　　echo "GRANT REPLICATION SLAVE ON *.* TO '$MYSQL_REPLICA_USER'@'%'; " | "${mysql[@]}"
　　# REPLICATION CLIENT privileges are required to get master position
　　echo "GRANT REPLICATION CLIENT ON *.* TO '$MYSQL_REPLICA_USER'@'%'; " | "${mysql[@]}"
　　fi
　　

　　#
　　# On the slave: point to a master server
　　#
　　if [ "$MYSQL_MASTER_SERVER" ]; then
　　MYSQL_MASTER_PORT=${MYSQL_MASTER_PORT:-3306}
　　MYSQL_MASTER_WAIT_TIME=${MYSQL_MASTER_WAIT_TIME:-3}
　　

　　if [ -z "$MYSQL_REPLICA_USER" ]; then
　　echo >&2 'error: MYSQL_REPLICA_USER not set'
　　exit 1
　　fi
　　if [ -z "$MYSQL_REPLICA_PASS" ]; then
　　echo >&2 'error: MYSQL_REPLICA_PASS not set'
　　exit 1
　　fi
　　

　　# Wait for eg. 10 seconds for the master to come up
　　# do at least one iteration
　　for i in $(seq $((MYSQL_MASTER_WAIT_TIME + 1))); do
　　if ! mysql "-u$MYSQL_REPLICA_USER" "-p$MYSQL_REPLICA_PASS" "-h$MYSQL_MASTER_SERVER" -e 'select 1;' |grep -q 1; then
　　echo >&2 "Waiting for $MYSQL_REPLICA_USER@$MYSQL_MASTER_SERVER"
　　sleep 1
　　else
　　break
　　fi
　　done
　　

　　if [ "$i" -gt "$MYSQL_MASTER_WAIT_TIME" ]; then
　　echo 2>&1 "Master is not reachable"
　　exit 1
　　fi
　　

　　# Get master position and set it on the slave. NB: MASTER_PORT and MASTER_LOG_POS must not be quoted
　　MasterPosition=$(mysql "-u$MYSQL_REPLICA_USER" "-p$MYSQL_REPLICA_PASS" "-h$MYSQL_MASTER_SERVER" -e "show master status \G" | awk '/Position/ {print $2}')
　　MasterFile=$(mysql  "-u$MYSQL_REPLICA_USER" "-p$MYSQL_REPLICA_PASS" "-h$MYSQL_MASTER_SERVER"   -e "show master status \G"     | awk '/File/ {print $2}')
　　echo "CHANGE MASTER TO MASTER_HOST='$MYSQL_MASTER_SERVER', MASTER_PORT=$MYSQL_MASTER_PORT, MASTER_USER='$MYSQL_REPLICA_USER', MASTER_PASSWORD='$MYSQL_REPLICA_PASS', MASTER_LOG_FILE='$MasterFile', MASTER_LOG_POS=$MasterPosition;"  | "${mysql[@]}"
　　

　　echo "START SLAVE;"  | "${mysql[@]}"
　　fi
　　----------------------------------------------------------------
　　docker-compose.yml
　　-------------------------
　　version: '2'
　　services:
　　master:
　　image: twang2218/mysql:5.7-replica
　　build: .
　　ports:
　　- 3308:3306
　　environment:
　　- MYSQL_ROOT_PASSWORD=Passw0rd
　　- MYSQL_REPLICA_USER=backup
　　- MYSQL_REPLICA_PASS=123
　　command: ["mysqld", "--log-bin=mysql-bin", "--server-id=1"]
　　slave:
　　image: twang2218/mysql:5.7-replica
　　ports:
　　- 3309:3306
　　environment:
　　- MYSQL_ROOT_PASSWORD=Passw0rd
　　- MYSQL_REPLICA_USER=backup
　　- MYSQL_REPLICA_PASS=123
　　- MYSQL_MASTER_SERVER=master
　　- MYSQL_MASTER_WAIT_TIME=10
　　command: ["mysqld", "--log-bin=mysql-bin", "--server-id=2"]