1. 配置CentOS 7的防火墙

• CentOS 7 默认使用的防火墙是firewall，开启TCP端口80:
  [root@localhost ~]# firewall-cmd --zone=public --add-port=80/tcp --permanent
• 重新启动防火墙让更改立刻生效:
  [root@localhost ~]# firewall-cmd --reload
• 检查端口是否开放：
  [root@localhost ~]# firewall-cmd --list-all
• 查看firewall服务状态:
  [root@localhost ~]# firewall-cmd --state

补充：

• systemctl --failed :检查加载失败的服务
• systemctl status network :查看网络服务状态
• systemctl stop firewalld.service : 关闭firewalld防火墙
• systemctl disable firewalld.service : 禁止firewalld开机启动
• systemctl start firewalld.service : 开启firewalld防火墙
• systemctl restart firewalld.service : 重启firewalld防火墙

2.使用links来浏览网站

• 安装links工具: yum install links 安装过程中，遇到选项，一路y即可。

  如：links localhost 或者 links www.baidu.com

3.安装Apache HTTP服务器

• 安装 Apache HTTP # yum install httpd

• 允许HTTP服务通过防火墙

  # firewall-cmd --add-service=http

• 永久添加HTTP服务配置

  # firewall-cmd --add-service=http --permanent

• 重新加载防火墙

  # firewall-cmd --reload

• 重启Apache HTTP服务器

  # systemctl restart httpd.service

  将Apache服务添加到系统，随系统自动启动
  # systemctl start httpd.service
# systemctl enable httpd.service

• 通过links 命令验证Apache HTTP 服务器

  # links 127.0.0.1

Ctrl+z 退出界面

4.安装mysql

1) [root@localhost ~]# yum install mysql-server

Loaded plugins: fastestmirrorLoading mirror speeds from cached hostfile* hase: mirrors.sina.cn* extras: mirrors.sina.cn* updates: mirrors.sina.cn
No package mysql-server available.
Error: Nothing to do

经查CentOS 7 版本将MySQL数据库软件从默认的程序列表中移除，用mariadb代替了。

MariaDB 是 MySQL 的一个分支。RHEL 以及它的衍生版已经从 MySQL 迁移到 MariaDB。这是一个主流的数据库管理系统。在最小化安装的 CentOS 上安装 MariaDB，如下所示:
[root@localhost ~]# yum install mariadb-server mariadb

mariadb数据库的相关命令是：
systemctl start mariadb  #启动MariaDB
systemctl stop mariadb  #停止MariaDB
systemctl restart mariadb  #重启MariaDB
systemctl enable mariadb  #设置开机启动
所以先启动数据库
[root@localhost ~]# systemctl start mariadb

然后就可以正常使用mysql了

[root@localhost ~]# mysql -u root -p
Enter password:
Welcome to the MariaDB monitor.  Commands end with ; or \g.
Your MariaDB connection id is 3
Server version: 5.5.41-MariaDB MariaDB Server  Copyright (c) 2000, 2014, Oracle, MariaDB Corporation Ab and others.  Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.  MariaDB [(none)]> show databases;
+--------------------+
| Database   |
+--------------------+
| information_schema |
| mysql  |
| performance_schema |
| test   |
+--------------------+
4 rows in set (0.00 sec)  MariaDB [(none)]>  

2) 下载mysql进行安装

# wget http://dev.mysql.com/get/mysql-community-release-el7-5.noarch.rpm
# rpm -ivh mysql-community-release-el7-5.noarch.rpm
# yum install mysql-community-server

安装成功后重启mysql服务。
# service mysqld restart
初次安装mysql，root账户没有密码。

[root@yl-web yl]# mysql -u root
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 3
Server version: 5.6.37 MySQL Community Server (GPL)Copyright (c) 2000, 2017, 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> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
+--------------------+
3 rows in set (0.01 sec)mysql> 

设置密码

mysql> set password for 'root'@'localhost' =password('password');
Query OK, 0 rows affected (0.00 sec)mysql> 

不需要重启数据库即可生效。

查看mysql字符集配置：

mysql>show variables like 'character%'

mysql配置文件为/etc/my.cnf
最后加上编码配置

[mysqld]
character_set_server = utf8

字符编码必须和/usr/share/mysql/charsets/Index.xml中保持一致。

把在所有数据库的所有表的所有权限赋值给位于所有IP地址的root用户。

mysql> grant all privileges on *.* to root@'%'identified by 'password';

如果不是root用户，则要先新建用户

mysql>create user 'username'@'%' identified by 'password';

查看安装的软件：

[root@localhost ~]# yum list installed | grep mysql

[root@localhost ~]# rpm -qa | grep -i mysql