AWS将ec2-user改为root用户登录

本次登录使用的ec2-user用户，如果使用root登录会提示：
Please login as the user "ec2-user" rather than the user "root".

解决此问题方法：

a、为root用户创建密码

[ec2-user@hostname ~]$ sudo passwd root
Changing password for user root.
New password: 
BAD PASSWORD: The password is shorter than 8 characters
Retype new password: 
passwd: all authentication tokens updated successfully.

b、为ec2-user用户创建密码

[ec2-user@hostname ~]$ su - root
Password: 
Last login: Sun Jun 12 02:42:00 EDT 2016 from 211.157.159.11 on pts/1
[root@hostname ~]# passwd ec2-user
Changing password for user ec2-user.
New password: 
BAD PASSWORD: The password is shorter than 8 characters
Retype new password: 
passwd: all authentication tokens updated successfully.

c、修改ssh配置文件

[root@hostname ~]# vi /etc/ssh/sshd_config 
PasswordAuthentication yes
PermitRootLogin yes
UsePAM no
(退出保存:i或o进入编辑, Esc退出编辑, :wq保存退出vim)

d、修改authorized_keys文件

sed -ri 's/^/#/;s/sleep 10"\s+/&\n/' /root/.ssh/authorized_keys

e、重启sshd服务

service sshd restart            ##linux 7之前的版本通常使用
systemctl restart sshd.service  ##linux 7之后使用(替代service、chkconfig)