要求
脚本实现在A机器，远程安装软件package到B机器
思路
将需要安装的软件包package从A拷贝到B，然后从A机器ssh到B远程执行安装脚本
为了用户能更方便的安装xx服务，决定用shell写一个工具，实现在本地远程安装服务包，限时1天，由于之前shell写得少，实现过程中遇到很多比较基础的问题，记录一下
实现version1
业务相关信息用xxx param4等屏蔽
#!/bin/bash
function help()
{
#usage
cat << HELP
------------------------------------------------------------------------------
please input 4 parameters in order:
1st: path of xxx package,
2nd: ip of the host which xxx will install
3rd: root's paasword of the host you inputted just now(2nd parameter)
4th: param4
Example:
/opt/test/xx.zip 192.168.0.2 YourPaasWord param4
HELP
}
function install()
{
read -a array
echo ${array[*]}
scp ${array[0]} root@${array[1]}:/
echo "bash setup.sh -param ${array[3]}"
ssh root@${array[1]} "mkdir -p /opt/test && \
cd /opt/test && \
cp /xx-*.zip ./ && \
unzip xx-*.zip && \
cd /opt/test/bin && \
bash setup.sh -param ${array[3]} "
# bash setup.sh -param ${array[3]} >/dev/null 2>&1 &"
################################################
# ssh root@${array[1]} 'mkdir -p /opt/test && \
# cd /opt/test && \
# cp /xx-*.zip ./ && \
# unzip xx-*.zip && \
# cd /opt/test/bin && \
# bash setup.sh -param ${array[3]} '
################################################
}
while [ 1 ]
do
help
install
sleep 1
done
问题记录
-
shell语言中&& & ; 区别
If previous command failed with ; the second one will run.
But with && the second one will not run.This is a "lazy" logical "AND" operand between operations.
If a command is terminated by the control operator &, the shell executes the command in the background in a subshell. The shell does not wait for the command to finish, and the return status is 0.
-
传参接收不到
按照被注释调ssh写法，即
################################################
# ssh root@${array[1]} 'mkdir -p /opt/test && \
# cd /opt/test && \
# cp /xx-*.zip ./ && \
# unzip xx-*.zip && \
# cd /opt/test/bin && \
# bash setup.sh -param ${array[3]} '
################################################
ssh执行bash setup.sh -param ${array[3]}命令时，${array[3]}值一直为空，不管怎么样都传递不进去。
中间google了很多答案，都没解决，后来抱着解决问题优先的态度，打算先把变量值写到远端主机的一个临时文件里，用的时候再读取（用tempvar=$(cat /opt/test/bin/temp.txt)或tempvar=$(< /opt/test/bin/temp.txt)读取到变量tempvar，再使用），试了也不行；
后来折腾了一个多小时，发现是低级错误（初学者的代价啊cry），将ssh需要执行的命令用"引起了（而非'）就好了，即ssh root@${array[1]} 'mkdir -p /opt/test && \ mkdir前的'以及最后的'换成"
贴一个区分单引号、双引号、反引号的链接：
http://www.cnblogs.com/gx-303841541/archive/2012/10/25/2740333.html
-
ssh登陆到远端主机执行的命令怎么能不显示
使用>/dev/null 2>&1重定向（源码中被注释掉了# bash setup.sh -param ${array[3]} >/dev/null 2>&1 &"）
>/dev/null 2>&1是什么鬼？
>is for redirect
/dev/null is a black hole where any data sent, will be discarded
2 is the file descriptor for Standard Error
> is for redirect
& is the symbol for file descriptor (without it, the following 1 would be considered a filename)
1 is the file descriptor for Standard Out
Therefore >/dev/null 2>&1 is redirect the output of your program to /dev/null. Include both the Standard Error and Standard Out.
Reference
https://stackoverflow.com/questions/6152659/bash-sh-difference-between-and
https://stackoverflow.com/questions/13338870/what-does-at-the-end-of-a-linux-command-mean
https://stackoverflow.com/questions/3314660/passing-variables-in-remote-ssh-command
https://unix.stackexchange.com/questions/163352/what-does-dev-null-21-mean-in-this-article-of-crontab-basics
