突然發現mysql都有8.0了，且效能提升比較明顯，就自己裝來玩玩。

centos的yum源中預設是沒有mysql的，所以我們需要先去官網下載mysql的repo源並安裝；

#yum repolist all | grep mysql

mysql-connectors-community/x86_64 MySQL Connectors Community         啟用:    24
mysql-connectors-community-source MySQL Connectors Community - Sourc 禁用
mysql-tools-community/x86_64      MySQL Tools Community              啟用:    38
mysql-tools-community-source      MySQL Tools Community - Source     禁用
mysql-tools-preview/x86_64        MySQL Tools Preview                禁用
mysql-tools-preview-source        MySQL Tools Preview - Source       禁用
mysql55-community/x86_64          MySQL 5.5 Community Server         禁用
mysql55-community-source          MySQL 5.5 Community Server - Sourc 禁用
mysql56-community/x86_64          MySQL 5.6 Community Server         禁用
mysql56-community-source          MySQL 5.6 Community Server - Sourc 禁用
mysql57-community/x86_64          MySQL 5.7 Community Server         啟用:   267
mysql57-community-source          MySQL 5.7 Community Server - Sourc 禁用
mysql80-community/x86_64          MySQL 8.0 Community Server         禁用
mysql80-community-source          MySQL 8.0 Community Server - Sourc 禁用
 

這裡顯示的是5.7的包，我們可以修改原始檔，禁用5.7，啟用8.0

#/etc/yum.repos.d/mysql-community.repo

把8.0enabled改為1就可以了，其他的版本改為0

[mysql-connectors-community]
name=MySQL Connectors Community
baseurl=http://repo.mysql.com/yum/mysql-connectors-community/el/7/$basearch/
enabled=1
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-mysql

[mysql-tools-community]
name=MySQL Tools Community
baseurl=http:
 
//repo.mysql.com/yum/mysql-tools-community/el/7/$basearch/
enabled=1
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-mysql

# Enable to use MySQL 5.5
[mysql55-community]
name=MySQL 5.5 Community Server
baseurl=http://repo.mysql.com/yum/mysql-5.5-community/el/7/$basearch/
enabled=0
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-mysql

# Enable to use MySQL 5.6
 

[mysql56-community]
name=MySQL 5.6 Community Server
baseurl=http://repo.mysql.com/yum/mysql-5.6-community/el/7/$basearch/
enabled=0
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-mysql

[mysql57-community]
name=MySQL 5.7 Community Server
baseurl=http://repo.mysql.com/yum/mysql-5.7-community/el/7/$basearch/
enabled=0
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-mysql

[mysql80-community]
name=MySQL 8.0 Community Server
baseurl=http://repo.mysql.com/yum/mysql-8.0-community/el/7/$basearch/
enabled=1
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-mysql

[mysql-tools-preview]
name=MySQL Tools Preview
baseurl=http://repo.mysql.com/yum/mysql-tools-preview/el/7/$basearch/
enabled=0
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-mysql

修改完成之後檢視可用的版本

#yum repolist enabled | grep mysql

mysql-connectors-community/x86_64 MySQL Connectors Community                  24
mysql-tools-community/x86_64      MySQL Tools Community                       38
mysql57-community/x86_64          MySQL 8.0 Community Server                 146

如果看到8.0版本啟用了之後就可以安裝MySql了

#yum install -y mysql-community-server  (過程會稍微有些慢，耐心等待）

安裝完成之後，就可以啟動mysql了

#systemctl start mysqld

檢視MySql的啟動狀態

#systemctl status mysqld

Redirecting to /bin/systemctl status  mysqld.service
● mysqld.service - MySQL Server
   Loaded: loaded (/usr/lib/systemd/system/mysqld.service; enabled; vendor preset: disabled)
   Active: active (running) since Fri 2018-05-11 23:34:51 CST; 11s ago
     Docs: man:mysqld(8)
           http://dev.mysql.com/doc/refman/en/using-systemd.html
  Process: 12421 ExecStartPre=/usr/bin/mysqld_pre_systemd (code=exited, status=0/SUCCESS)
 Main PID: 12661 (mysqld)
   Status: "SERVER_OPERATING"
   CGroup: /system.slice/mysqld.service
           └─12661 /usr/sbin/mysqld


May 11 23:34:42 VM_0_7_centos systemd[1]: Starting MySQL Server...
May 11 23:34:51 VM_0_7_centos systemd[1]: Started MySQL Server.

開機啟動設定

#systemctl enable mysqld
#systemctl daemon-reload

MySql安裝完成之後會在LOG檔案(/var/log/mysqld.log)中生成一個root的預設密碼

#grep 'temporary password' /var/log/mysqld.log 

2018-05-11T15:34:46.440387Z 5 [Note] [MY-010454] [Server] A temporary password is generated for [email protected]: hqm8r1xXy3<r

登入MySql並修改root密碼

#mysql -uroot -p
mysql>ALTER USER 'root'@'localhost' IDENTIFIED BY 'new psd'; 

#密碼強度預設為中等，大小寫字母、數字、特殊符號，只有修改成功後才能修改配置再設定更簡單的密碼

擴充套件閱讀：mysql的密碼策略

mysql>show variables like '%validate_password%';

+---------------------------------------+--------+
| Variable_name                         | Value  |
+---------------------------------------+--------+
| validate_password_check_user_name     | ON     |
| validate_password_dictionary_file     |        |
| validate_password_length              | 8      |
| validate_password_mixed_case_count    | 1      |
| validate_password_number_count        | 1      |
| validate_password_policy              | MEDIUM |
| validate_password_special_char_count  | 1      |
+---------------------------------------+--------+
7 rows in set (0.01 sec)

預設的密碼策略

validate_password_policy：密碼策略，預設為MEDIUM策略 
validate_password_dictionary_file：密碼策略檔案，策略為STRONG才需要 
validate_password_length：密碼最少長度 
validate_password_mixed_case_count：大小寫字元長度，至少1個 
validate_password_number_count ：數字至少1個 
validate_password_special_char_count：特殊字元至少1個 

修改密碼策略
在/etc/my.cnf檔案新增validate_password_policy配置：

# 選擇0（LOW），1（MEDIUM），2（STRONG）其中一種，選擇2需要提供密碼字典檔案
validate_password_policy=0或者set global validate_password.policy=0;

修改預設編碼
在/etc/my.cnf配置檔案的[mysqld]下新增編碼配置：

[mysqld]
character_set_server=utf8
init_connect='SET NAMES utf8'

重啟mysql，是修改生效

#systemctl restart mysqld

遠端登入使用者新增

mysql> GRANT ALL PRIVILEGES ON . TO 'admin'@'%' IDENTIFIED BY '*****' WITH GRANT OPTION;
mysql> FLUSH PRIVILEGES;

檢視使用者

mysql> select host,user from mysql.user;

+-----------+------------------+
| host      | user             |
+-----------+------------------+
| localhost | mysql.infoschema |
| localhost | mysql.session    |
| localhost | mysql.sys        |
| localhost | root             |
+-----------+------------------+
4 rows in set (0.00 sec)

搞定~

我的系統SELinux預設是disable的，所以就不管了。

vim /etc/selinux/config,把SELINUX改為disable即可。

增加3306埠：vim /etc/sysconfig/iptables新增-A INPUT -p tcp -m state --state NEW -m tcp --dport 3306 -j ACCEPT