MySQL 8.0权限认证(下)
一.设置MySQL用户资源限制
通过设置全局变量max_user_connections可以限制所有用户在同一时间连接MySQL实例的数量,但此参数无法对每个用户区别对待,
所以 MySQL提供了对每个用户的资源限制管理
MAX_QUERIES_PER_HOUR:一个用户在一个小时内可以执行查询的次数(基本包含所有语句) MAX_UPDATES_PER_HOUR:一个用户在一个小时内可以执行修改的次数(仅包含修改数据库或表的语句) MAX_CONNECTIONS_PER_HOUR:一个用户在一个小时内可以连接 MySQL的时间
MAX_USER_CONNECTIONS:一个用户可以在同一时间连接MySQL实例的数量
从5.0.3版本开始,对用户'user'@'%.example.com'的资源限制是指所有 通过example.com域名主机连接user用户的连接,而不是分别指从 host1.example.com和host2.example.com主机过来的连接
通过执行create user/alter user设置/修改用户的资源限制
mysql> CREATE USER 'francis'@'localhost' IDENTIFIED BY 'frank'
-> WITH MAX_QUERIES_PER_HOUR 20
-> MAX_UPDATES_PER_HOUR 10
-> MAX_CONNECTIONS_PER_HOUR 5
-> MAX_USER_CONNECTIONS 2;
mysql> ALTER USER 'francis'@'localhost' WITH MAX_QUERIES_PER_HOUR 100;
取消某项资源限制既是把原先的值修改成0
mysql> ALTER USER 'francis'@'localhost' WITH MAX_CONNECTIONS_PER_HOUR 0;
当针对某个用户的max_user_connections非0时,则忽略全局系统参数 max_user_connections,反之则全局系统参数生效
二.设置MySQL用户的密码
执行create user创建用户和密码
mysql> CREATE USER 'jeffrey'@'localhost' IDENTIFIED BY 'mypass';
修改用户密码的方式包括:
mysql> ALTER USER 'jeffrey'@'localhost' IDENTIFIED BY 'mypass';
mysql> SET PASSWORD FOR 'jeffrey'@'localhost' = PASSWORD('mypass');
mysql> GRANT USAGE ON *.* TO 'jeffrey'@'localhost' IDENTIFIED BY 'mypass';
shell> mysqladmin -u user_name -h host_name password "new_password"
修改本身用户密码的方式包括:
mysql> ALTER USER USER() IDENTIFIED BY 'mypass';
mysql> SET PASSWORD = PASSWORD('mypass');
三.设置MySQL用户密码过期策略
设置系统参数default_password_lifetime作用于所有的用户账户
default_password_lifetime=180 设置180天过期
default_password_lifetime=0 设置密码不过期
如果为每个用户设置了密码过期策略,则会覆盖上述系统参数
ALTER USER 'jeffrey'@'localhost' PASSWORD EXPIRE INTERVAL 90 DAY;
ALTER USER 'jeffrey'@'localhost' PASSWORD EXPIRE NEVER; 密码不过期
ALTER USER 'jeffrey'@'localhost' PASSWORD EXPIRE DEFAULT; 默认过期策略
手动强制某个用户密码过期
ALTER USER 'jeffrey'@'localhost' PASSWORD EXPIRE;
mysql> SELECT 1;
ERROR 1820 (HY000): You must SET PASSWORD before executing this statement
mysql> ALTER USER USER() IDENTIFIED BY 'new_password';
Query OK, 0 rows affected (0.01 sec)
四.角色(role)和用户(user)
role是8.0的新特性 NEW!
role可以看做一个权限的集合，这个集合有一个统一的名字role名。可以给多个账户统一的某个role的权限权限的修改直接通过修改role来实现，不需要每个账户一个一个的grant权限，方便运维和管理。role可以创建、删除、修改并作用到他管理的账户上。
mysql> create role app_readonly;
Query OK, 0 rows affected (0.09 sec)
#创建一个role叫app_readonly只读
mysql> create user app1@localhost identified by 'mysql';
Query OK, 0 rows affected (0.01 sec)
#创建一个用户app1
mysql> grant select on *.* to app_readonly;
Query OK, 0 rows affected (0.02 sec)
#给app_readonly这个角色一个select权限
mysql> grant app_readonly to app1@localhost;
Query OK, 0 rows affected (0.10 sec)
#把用户和角色绑定
mysql> show grants for app1@localhost;
+------------------------------------------------+
| Grants for app1@localhost |
+------------------------------------------------+
| GRANT USAGE ON *.* TO `app1`@`localhost` |
| GRANT `app_readonly`@`%` TO `app1`@`localhost` |
+------------------------------------------------+
#查询用户的权限
mysql> show grants for app1@localhost using app_readonly;
+------------------------------------------------+
| Grants for app1@localhost |
+------------------------------------------------+
| GRANT SELECT ON *.* TO `app1`@`localhost` |
| GRANT `app_readonly`@`%` TO `app1`@`localhost` |
+------------------------------------------------+
2 rows in set (0.00 sec)
#查询用户的权限
mysql> create role app_readwrite;
Query OK, 0 rows affected (0.04 sec)
mysql> create user app2@localhost identified by 'mysql';
Query OK, 0 rows affected (0.04 sec)
mysql> grant select,insert,delete,update on *.* to app_readwrite;
Query OK, 0 rows affected (0.10 sec)
mysql> grant app_readwrite to app2@localhost;
Query OK, 0 rows affected (0.07 sec)
mysql> show grants for app2@localhost;
+-------------------------------------------------+
| Grants for app2@localhost |
+-------------------------------------------------+
| GRANT USAGE ON *.* TO `app2`@`localhost` |
| GRANT `app_readwrite`@`%` TO `app2`@`localhost` |
+-------------------------------------------------+
2 rows in set (0.00 sec)
mysql> show grants for app2@localhost using app_readwrite;
+-------------------------------------------------------------------+
| Grants for app2@localhost |
+-------------------------------------------------------------------+
| GRANT SELECT, INSERT, UPDATE, DELETE ON *.* TO `app2`@`localhost` |
| GRANT `app_readwrite`@`%` TO `app2`@`localhost` |
+-------------------------------------------------------------------+
2 rows in set (0.00 sec)
mysql> revoke app_readonly from app1@localhost;
Query OK, 0 rows affected (0.10 sec)
#解除绑定关系
mysql> show grants for app1@localhost using app_readonly;
ERROR 3530 (HY000): `app_readonly`@`%` is not granted to `app1`@`localhost`
mysql> show grants for app1@localhost;
+------------------------------------------+
| Grants for app1@localhost |
+------------------------------------------+
| GRANT USAGE ON *.* TO `app1`@`localhost` |
+------------------------------------------+