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

脚本启动zookeeper集群-LMLPHP

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
06-03 14:32