本實驗完成以下測試需求：
需求一：驗證'%'是否包含'localhost'
需求二：驗證localhost和127.0.0.1分別使用的連線協議
版本：mariadb 10.1.12


一.驗證'%'是否包含'localhost'
先建立帳號和授權:
MariaDB [(none)]> grant all privileges on *.* to 'avapps'@'%' identified by "av166apps";
Query OK, 0 rows affected (0.00 sec)


MariaDB [(none)]> flush privileges;
Query OK, 0 rows affected (0.00 sec)


MariaDB [(none)]> exit
Bye
[

[email protected] ~]$ mysql -uavapps -pav166apps  --socket=/tmp/mysql3306.sock
ERROR 1045 (28000): Access denied for user 'avapps'@'localhost' (using password: YES)
當只有'avapps'@'%'有許可權時，無法登入。
MariaDB [(none)]> select user,host from mysql.user;
+---------+-----------+
| user    | host      |
+---------+-----------+
| avapps | %         |
| root    | 127.0.0.1 |
| root    | ::1       |
|         | localhost |
| root    | localhost |
|         | m2972  |
| root    | m2972  |
+---------+-----------+
7 rows in set (0.00 sec)


再增加

[email protected]'localhost'使用者：
MariaDB [(none)]> grant all privileges on *.* to [email protected]'localhost' identified by 'av166apps';
Query OK, 0 rows affected (0.00 sec)
MariaDB [(none)]> select user,host from mysql.user;
+---------+-----------+
| user    | host      |
+---------+-----------+
| avapps | %         |
| root    | 127.0.0.1 |
| root    | ::1       |
|         | localhost |
| avapps | localhost |
| root    | localhost |
|         | m2972  |
| root    | m2972  |
+---------+-----------+
[

[email protected] ~]$ mysql -uavapps -pav166apps  --socket=/tmp/mysql3306.sock
Welcome to the MariaDB monitor.  Commands end with ; or \g.
Your MariaDB connection id is 28
Server version: 10.1.12-MariaDB MariaDB Server


Copyright (c) 2000, 2016, Oracle, MariaDB Corporation Ab and others.


Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.


MariaDB [(none)]>


現在能正常登入。
說明'%'是不包含'localhost'


二.驗證localhost和127.0.0.1分別使用的連線協議


1.在skip_name_resolve為開啟狀態下：
MariaDB [(none)]> show variables like 'skip%';
+---------------------------+-------+
| Variable_name             | Value |
+---------------------------+-------+
| skip_external_locking     | ON    |
| skip_name_resolve         | ON    |
| skip_networking           | OFF   |
| skip_parallel_replication | OFF   |
| skip_replication          | OFF   |
| skip_show_database        | OFF   |


先drop使用者'avapps'@'%'
MariaDB [(none)]> drop user 'avapps'@'%';
Query OK, 0 rows affected (0.00 sec)


MariaDB [(none)]> exit
Bye
[[email protected] ~]$ mysql -uavapps -pav166apps -h 127.0.0.1
ERROR 1045 (28000): Access denied for user 'avapps'@'127.0.0.1' (using password: YES)


 


mysql -uavapps -pav166apps -h 127.0.0.1


通過127.0.0.1連線時使用TCP/IP協議：
[[email protected] ~]$ mysql -uavapps -pav166apps -h 127.0.0.1
Welcome to the MariaDB monitor.  Commands end with ; or \g.
Your MariaDB connection id is 34
Server version: 10.1.12-MariaDB MariaDB Server


Copyright (c) 2000, 2016, Oracle, MariaDB Corporation Ab and others.


Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.


MariaDB [(none)]> \s
--------------
mysql  Ver 15.1 Distrib 10.1.12-MariaDB, for Linux (x86_64) using readline 5.1


Connection id:          34
Current database:
Current user:           [email protected]
SSL:                    Not in use
Current pager:          stdout
Using outfile:          ''
Using delimiter:        ;
Server:                 MariaDB
Server version:         10.1.12-MariaDB MariaDB Server
Protocol version:       10
Connection:             127.0.0.1 via TCP/IP
Server characterset:    utf8
Db     characterset:    utf8
Client characterset:    utf8
Conn.  characterset:    utf8
TCP port:               3306
Uptime:                 1 day 22 hours 14 min 17 sec


Threads: 2  Questions: 68  Slow queries: 0  Opens: 0  Flush tables: 1  Open tables: 11  Queries per second avg: 0.000


不加127.0.0.1時，預設連線使用socket協議:
[[email protected] ~]$ mysql -uavapps -pav166apps
Welcome to the MariaDB monitor.  Commands end with ; or \g.
Your MariaDB connection id is 35
Server version: 10.1.12-MariaDB MariaDB Server


Copyright (c) 2000, 2016, Oracle, MariaDB Corporation Ab and others.


Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.


MariaDB [(none)]> \s
--------------
mysql  Ver 15.1 Distrib 10.1.12-MariaDB, for Linux (x86_64) using readline 5.1


Connection id:          35
Current database:
Current user:           [email protected]
SSL:                    Not in use
Current pager:          stdout
Using outfile:          ''
Using delimiter:        ;
Server:                 MariaDB
Server version:         10.1.12-MariaDB MariaDB Server
Protocol version:       10
Connection:             Localhost via UNIX socket
Server characterset:    utf8
Db     characterset:    utf8
Client characterset:    utf8
Conn.  characterset:    utf8
UNIX socket:            /tmp/mysql3306.sock
Uptime:                 1 day 22 hours 14 min 54 sec


Threads: 2  Questions: 72  Slow queries: 0  Opens: 0  Flush tables: 1  Open tables: 11  Queries per second avg: 0.000


加localhost連線使用socket協議:
[[email protected] ~]$ mysql -uavapps -pav166apps -h localhost
Welcome to the MariaDB monitor.  Commands end with ; or \g.
Your MariaDB connection id is 59
Server version: 10.1.12-MariaDB MariaDB Server


Copyright (c) 2000, 2016, Oracle, MariaDB Corporation Ab and others.


Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.


MariaDB [(none)]> \s
--------------
mysql  Ver 15.1 Distrib 10.1.12-MariaDB, for Linux (x86_64) using readline 5.1


Connection id:          59
Current database:
Current user:           [email protected]
SSL:                    Not in use
Current pager:          stdout
Using outfile:          ''
Using delimiter:        ;
Server:                 MariaDB
Server version:         10.1.12-MariaDB MariaDB Server
Protocol version:       10
Connection:             Localhost via UNIX socket
Server characterset:    utf8
Db     characterset:    utf8
Client characterset:    utf8
Conn.  characterset:    utf8
UNIX socket:            /tmp/mysql3306.sock
Uptime:                 1 day 22 hours 26 min 16 sec


Threads: 4  Questions: 371  Slow queries: 0  Opens: 0  Flush tables: 1  Open tables: 11  Queries per second avg: 0.002




2.在skip_name_resolve為停用狀態下：
更改配置檔案中skip_name_resolve為off，並重啟mysql.
MariaDB [(none)]> show variables like 'skip%';
+---------------------------+-------+
| Variable_name             | Value |
+---------------------------+-------+
| skip_external_locking     | ON    |
| skip_name_resolve         | OFF    |
| skip_networking           | OFF   |
| skip_parallel_replication | OFF   |
| skip_replication          | OFF   |
| skip_show_database        | OFF   |


停掉skip_name_resolve後，用127.0.0.1登入轉變成了localhost，用[email protected]'127.0.0.1'的密碼無法登入:
-bash-4.1$ mysql -uavapps -p -h 127.0.0.1 -P 3306
Enter password: 
ERROR 1045 (28000): Access denied for user 'avapps'@'localhost' (using password: YES)


-bash-4.1$ mysql -uavapps -p -h 127.0.0.1
Enter password: 
ERROR 1045 (28000): Access denied for user 'avapps'@'localhost' (using password: YES)


而用[email protected]'localhost'登入才成功，並且使用TCP/IPt協議：
-bash-4.1$ mysql -uavapps -p -h localhost
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
MariaDB [(none)]>


實驗總結：
1.授權中的'%'不包含'localhost';
2.skip_name_resolve開啟情況下，127.0.0.1連線時用'avapps'@'%'帳號使用TCP/IP協義，而預設或用localhost連線時使用socket協議;
3.skip_name_resolve關閉情況下，127.0.0.1連線會轉換成用'avapps'@'localhost'帳號使用TCP/IP協義，而預設或用localhost連線時使用socket協議;