shell 习题91 部署MySQL主从

用shell脚本实现，部署MySQL主从，假设两台机器上已经安装了MySQL，并且当前无新库。

核心要点

主从步骤

1. 主上更改配置文件，打开bin-log，设定server-id，设定ignore-db(忽略同步的库)，重启服务，授权用户，锁表，show master status
2. 从上修改配置文件，设定server-id，重启服务，stop slave，change master，start slave
3. 主上解开锁表
   思路：先在主上把1步骤完成再把2步骤逻辑写入到slave.sh再使用expect发送到从机器和执行slave.sh

代码内容

#!/bin/bash    
#    
#program:    
#    部署MySQL主从
#    
#history:    
#2020/02/27    kun    V1.0  

master_ip=192.168.100.12
slave_ip=192.168.100.13
mysqlc="mysql -uroot -ptest"

## 检测上一条命令是否执行成功的函数
check_ok()
{
    if [ $? -ne 0 ]
    then
        echo "$1 出错了。"
        exit 1
    fi
}

## 修改文件名字函数
f_exist()
{
    d=`date +%F%T`
    if [ -f $1 ]
    then
        mv $1 $1_$d
    fi
}

## 设置主mysql配置
if ! grep '^server-id' /etc/my.cnf
then
    ## 在[mysql]下一行添加server-id = 1001
    sed -i '/^\[mysqld\]$/a\server-id = 1001' /etc/my.cnf
fi

if ! grep '^log-bin.*=.*' /etc/my.cnf
then
    sed -i '/^\[mysqld\]$/a\log-bin = test' /etc/my.cnf
fi

sed -i '/^log-bin.*/a\binlog-ignore-db = mysql ' /etc/my.cnf

/etc/init.d/mysqld restart
check_ok "主上重启mysql"

## 登录mysql，授权用户、锁表以及show master status。
$mysqlc <<EOF
    grant replication slave on *.* to 'repl'@$slave_ip identified by 'yourpassword';
    flush tables with read lock;
EOF
$mysqlc -e "show master status" > /tmp/master.log
file=`tail -1 /tmp/master.log|awk '{print $1}'`
pos=`tail -1 /tmp/master.log|awk '{print $2}'`

## 创建在从上配置和操作的脚本
f_exist /tmp/slave.sh

## slave.sh发送到从上执行的脚本
cat > /tmp/slave.sh << EOF
#!/bin/bash
if ! grep '^server-id' /etc/my.cnf
then
    sed -i '/^\[mysqld\]$/a\server-id = 1002' /etc/my.cnf
fi

/etc/init.d/mysqld restart
check_ok "从上重启mysql"

$mysqlc  <<KUN
    stop slave;
    change master to master_host="$master_ip", master_user="repl", master_password="yourpassword", master_log_file="$file", master_log_pos=$pos;
    start slave;
KUN
EOF

## 创建传输slave.sh的expect脚本
f_exist /tmp/rs_slave.expect

## rs_slave.expect脚本把slave.sh发送从上
cat > /tmp/rs_slave.expect <<EOF
#!/usr/bin/expect
set passwd "root1234"
spawn rsync -a /tmp/slave.sh root@$slave_ip:/tmp/slave.sh
expect {
    "yes/no" { send "yes\r"}
    "password:" { send "\$passwd\r" }
}
expect eof
EOF

## 执行expect脚本
chmod +x /tmp/rs_slave.expect
/tmp/rs_slave.expect
check_ok "传输slave.sh"

## 创建远程执行命令的expect脚本
f_exist /tmp/exe.expect

##  exe.expect脚本远程执行从上的slave.sh
cat > /tmp/exe.expect <<EOF
#!/usr/bin/expect
set passwd "root1234"
spawn ssh root@$slave_ip
expect {
    "yes/no" { send "yes\r"}
    "password:" { send "\$passwd\r" }
}
expect "]*"
send "/bin/bash /tmp/slave.sh\r"
expect "]*"
send "exit\r"
EOF

## 执行expect脚本
chmod +x /tmp/exe.expect
/tmp/exe.expect
check_ok "远程执行slave.sh"

## 主上解锁表
$mysqlc -e "unlock tables"