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:

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FROM mysql:5.7

MAINTAINER Tao Wang <twang2218@gmail.com>

COPY replica.sh /docker-entrypoint-initdb.d/

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replica.sh 

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(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。)

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#!/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

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docker-compose.yml

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version: '2'

services:

    master:

        p_w_picpath: 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:

        p_w_picpath: 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"]