让普通用户可以sudo,并且不需要输入密码
[root@hadoop13 bin]# visudo
## Allow root to run any commands anywhere
root ALL=(ALL) ALL
hui ALL=NOPASSWD: ALL
必须先配置好ssh
图2-40 免密登陆原理
(2)生成公钥和私钥:
[atguigu@hadoop102 .ssh]$ ssh-keygen -t rsa
然后敲(三个回车),就会生成两个文件id_rsa(私钥)、id_rsa.pub(公钥)
(3)将公钥拷贝到要免密登录的目标机器上
[atguigu@hadoop102 .ssh]$ ssh-copy-id hadoop102
[atguigu@hadoop102 .ssh]$ ssh-copy-id hadoop103
[atguigu@hadoop102 .ssh]$ ssh-copy-id hadoop104
ssh hadoop103 看看是否能连上,且不用密码
3. .ssh文件夹下(~/.ssh)的文件功能解释
启动zookeeper集群脚本
#/bin/bash
echo '=======================start zookeeper======================='
for host in hadoop11 hadoop12 hadoop13
do
ssh $host "source /etc/profile;/opt/module/zookeeper-3.4.13/bin/zkServer.sh start"
if [$? -ne 0 ];then
echo "$host zookeeper 启动失败"
else
echo "$host zookeeper 启动成功"
fi
done