阿铭Linux

shell习题-自动增加公钥

写一个shell脚本，当我们执行时，提示要输入对方的ip和root密码，然后可以自动把本机的公钥增加到对方机器上，从而实现密钥认证。

参考答案：

#!/bin/bash

read -p "Input IP: " ip
ping $ip -w 2 -c 2 >> /dev/null

## 查看ip是否可用
while [ $? -ne 0 ]
do
    read -p "your ip may not useable, Please Input your IP: " ip
    ping $ip -w 2 -c 2 >> /dev/null
done
read -p "Input root\'s password of this host: " password

## 检查命令子函数

check_ok() {
if [ $? != 0 ]
then
    echo "Error!."
    exit 1
fi
}

## yum需要用到的包
myyum() {
if ! rpm -qa |grep -q "$1"
then
    yum install -y $1
    check_ok
else
    echo $1  already installed
fi
}

for p in openssh-clients openssh expect
do
    myyum $p
done

## 在主机A上创建密钥对

if [ ! -f ~/.ssh/id_rsa ] || [ ! -f ~/.ssh/id_rsa.pub ]
then
    if [ -d ~/.ssh ]
    then
        mv ~/.ssh/  ~/.ssh_old
    fi
    echo -e "\n" | ssh-keygen -t rsa -P ''
    check_ok
fi

## 传私钥给主机B

if [ ! -d /usr/local/sbin/rsync_keys ]
then
    mkdir /usr/local/sbin/rsync_keys
fi
cd /usr/local/sbin/rsync_keys
if [ -f rsync.expect ]
then
    d=`date +%F-%T`
    mv rsync.expect $d.expect
fi

#创建远程同步的expect文件

cat >  rsync.expect <<EOF
#!/usr/bin/expect
set host [lindex \$argv 0]
#主机B的密码
set passwd [lindex \$argv 1]
spawn rsync -av /root/.ssh/id_rsa.pub root@\$host:/tmp/tmp.txt
expect {
"yes/no" { send "yes\r"; exp_continue}
"password:" { send "\$passwd\r" }
}
expect eof
spawn ssh root@\$host
expect {
"password:" { send "\$passwd\r" }
}
expect "]*"                         
send "\[ -f /root/.ssh/authorized_keys \] && cat /tmp/tmp.txt >>/root/.ssh/authorized_keys \r"
expect "]*"
send "\[ -f /root/.ssh/authorized_keys \] || mkdir -p /root/.ssh/ \r"            
send "\[ -f /root/.ssh/authorized_keys \] || mv /tmp/tmp.txt /root/.ssh/authorized_keys\r"            
expect "]*"
send "chmod 700 /root/.ssh; chmod 600 /root/.ssh/authorized_keys\r"
expect "]*"
send "exit\r"
EOF

check_ok
/usr/bin/expect /usr/local/sbin/rsync_keys/rsync.expect $ip $password
echo "OK,this script is successful. ssh $ip  to test it"