MySQL5.7初始化后5种密码重置方法

前言：由于好几次安装MySQL5.7后一直被重置密码所困扰,因此特意整理重置的方法

安装MySQL5.7

[root@node1 db]# ll  以下的rpm安装包可以随处下载
total 402356
-rw-r--r-- 1 root root      24744 Nov 25  2015 libaio-0.3.109-13.el7.x86_64.rpm
-rw-r--r-- 1 7155 31415  25106088 Mar  5 10:24 mysql-community-client-5.7.22-1.el7.x86_64.rpm
-rw-r--r-- 1 7155 31415   3781636 Mar  5 10:24 mysql-community-devel-5.7.22-1.el7.x86_64.rpm
-rw-r--r-- 1 7155 31415   2239868 Mar  5 10:24 mysql-community-libs-5.7.22-1.el7.x86_64.rpm
-rw-r--r-- 1 7155 31415 172992596 Mar  5 10:25 mysql-community-server-5.7.22-1.el7.x86_64.rpm
[root@node1 db]#
[root@node1 db]# rpm -ivh *.rpm --nodeps --force
warning: mysql-community-client-5.7.22-1.el7.x86_64.rpm: Header V3 DSA/SHA1 Signature, key ID 5072e1f5: NOKEY
Preparing...                          ################################# [100%]
Updating / installing...
   1:mysql-community-libs-5.7.22-1.el7################################# [ 20%]
   2:mysql-community-client-5.7.22-1.e################################# [ 40%]
   3:libaio-0.3.109-13.el7            ################################# [ 60%]
   4:mysql-community-server-5.7.22-1.e################################# [ 80%]
   5:mysql-community-devel-5.7.22-1.el################################# [100%]

启动mysql
[root@node1 db]# systemctl start mysqld

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
Server version: 5.7.22
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.

登录后并不能任何操作
mysql> show databases;
ERROR 1820 (HY000): Unknown error 1820
mysql> select * from mysql;
ERROR 1046 (3D000):

方法1：使用alter修改

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。

方法2：使用set password

mysql> SET PASSWORD FOR 'root'@'localhost' = PASSWORD('Gerk087@&#@');  #第一次也要符合密友复杂度
Query OK, 0 rows affected, 1 warning (0.00 sec)

mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)

方法3：使用update

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)

方法4：使用mysql_secure_installation

[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!

方法5：跳过授权列表skip-grant-tables

[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)

Summary
a. mysql5.7安装好后会在/var/log/mysql.log中产随机密码,而且不修改密码不能执行任何操作
b. mysql5.7的user表中的password字串修改为authentication_string
c. 修改密码的Policy转变是1(中级),因此设置时要符合规则
d. 跳过授权列时,同时也不受密码policy影响