从日志中获取随机生成的密码
 
[root@node1 db]# grep password /var/log/mysqld.log
 
2018-07-15T09:01:09.735836Z 1 [Note] A temporary password is generated for root@localhost: ViFg8pWf+,lU
 
[root@node1 db]# mysql -uroot -pViFg8pWf+,lU
 
mysql: [Warning] Using a password on the command line interface can be insecure.
 
Welcome to the MySQL monitor.  Commands end with ; or \g.
 
Your MySQL connection id is 2

mysql> ALTER USER USER() IDENTIFIED BY ‘Reid790!@#$‘;
 
Query OK, 0 rows affected (0.00 sec)
 
 
mysql> ALTER USER ‘root‘@‘localhost‘ IDENTIFIED BY ‘Tom579#$%^&‘;  #针对localhost
 
Query OK, 0 rows affected (0.00 sec)
 
 
 
或者先关闭其密码策略修改
mysql> select @@validate_password_length;
 
ERROR 1820 (HY000): Unknown error 1820
mysql>  ALTER USER USER() IDENTIFIED BY ‘12345678‘;
 
Query OK, 0 rows affected (0.00 sec)
 
 
 
validate_password_policy有以下取值：
 
Policy  Tests Performed
 
0 or LOW    Length
 
1 or MEDIUM Length; numeric, lowercase/uppercase, and special characters
 
2 or STRONG Length; numeric, lowercase/uppercase, and special characters; dictionary file
 
默认是1，即MEDIUM，所以刚开始设置的密码必须符合长度，且必须含有数字，小写或大写字母，特殊字符。

[root@node1 db]# mysql
 
ERROR 1045 (28000): Unknown error 1045
 
[root@node1 db]# vim /etc/my.cnf  #使用完后去掉
 
[mysqld]
 
skip-grant-tables=1
 
 
 
重启mysql,再修改
 
[root@node1 db]# systemctl restart mysqld
 
[root@node1 db]# mysql
 
Welcome to the MySQL monitor.  Commands end with ; or \g.
 
Your MySQL connection id is 2
 
Server version: 5.7.22 MySQL Community Server (GPL)
 
 
 
Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved.
 
 
 
Oracle is a registered trademark of Oracle Corporation and/or its
 
affiliates. Other names may be trademarks of their respective
 
owners.
 
 
 
Type ‘help;‘ or ‘\h‘ for help. Type ‘\c‘ to clear the current input statement.
 
 
 
mysql> set password = PASSWORD(‘Reid4909@%&‘);
 
ERROR 1290 (HY000): Unknown error 1290
 
mysql> ALTER USER ‘root‘@‘localhost‘ IDENTIFIED BY ‘Tom579#$%^&‘;
 
ERROR 1290 (HY000): Unknown error 1290
 
mysql> flush privileges;
 
Query OK, 0 rows affected (0.00 sec)
 
 
 
mysql> set password = PASSWORD(‘Reid4909@%&‘);
 
ERROR 1133 (42000):
 
mysql> ALTER USER ‘root‘@‘localhost‘ IDENTIFIED BY ‘Tom579#$%^&‘;
 
Query OK, 0 rows affected (0.01 sec)
 
 
 
mysql> set password for root@localhost = password(‘123456‘);
 
Query OK, 0 rows affected, 1 warning (0.00 sec)
　　

[root@node1 db]# mysql_secure_installation
 
 
 
Securing the MySQL server deployment.
 
 
 
Enter password for user root: Marry583@&%!
 
The ‘validate_password‘ plugin is installed on the server.
 
The subsequent steps will run with the existing configuration
 
of the plugin.
 
Using existing password for root.
 
 
 
Estimated strength of the password: 100
 
Change the password for root ? ((Press y|Y for Yes, any other key for No) : y
 
 
 
New password: Tom579#$%^&
 
 
 
Re-enter new password: Tom579#$%^&
 
 
 
Estimated strength of the password: 100
 
Do you wish to continue with the password provided?(Press y|Y for Yes, any other key for No) : y
 
By default, a MySQL installation has an anonymous user,
 
allowing anyone to log into MySQL without having to have
 
a user account created for them. This is intended only for
 
testing, and to make the installation go a bit smoother.
 
You should remove them before moving into a production
 
environment.
 
为了安全应该yes
 
Remove anonymous users? (Press y|Y for Yes, any other key for No) : No
 
 
 
 ... skipping.
 
 
 
 
 
Normally, root should only be allowed to connect from
 
‘localhost‘. This ensures that someone cannot guess at
 
the root password from the network.
 
为了安全应该yes
 
Disallow root login remotely? (Press y|Y for Yes, any other key for No) : No
 
 
 
 ... skipping.
 
By default, MySQL comes with a database named ‘test‘ that
 
anyone can access. This is also intended only for testing,
 
and should be removed before moving into a production
 
environment.
 
 
 
为了安全应该yes
 
Remove test database and access to it? (Press y|Y for Yes, any other key for No) : No 
 
 
 
 ... skipping.
 
Reloading the privilege tables will ensure that all changes
 
made so far will take effect immediately.
 
 
 
Reload privilege tables now? (Press y|Y for Yes, any other key for No) : y
 
Success.
 
 
 
All done!

mysql> UPDATE mysql.user SET authentication_string = PASSWORD(‘Marry583@&%!‘), password_expired = ‘N‘ WHERE User = ‘root‘ AND Host = ‘localhost‘;
 
Query OK, 1 row affected, 1 warning (0.00 sec)
 
 
 
mysql> flush privileges;
 
Query OK, 0 rows affected (0.00 sec)

mysql> create user ‘root‘@‘%‘ identified with mysql_native_password by ‘your password‘;
Query OK, 0 rows affected (0.01 sec)

mysql> grant all privileges on *.* to ‘root‘@‘%‘ with grant option;
Query OK, 0 rows affected (0.01 sec)

mysql> flush privileges;
Query OK, 0 rows affected (0.01 sec)