详解centos系统安装mysql8一、准备工作 1、更新包 2、查看是否已经安装过mysql 3、删除mysql 4、

一、准备工作

1、更新包
```
yum update   
```
2、查看是否已经安装过mysql
```
rpm -qa | grep -i mysql
```
3、删除mysql
```
yum -y remove MySQL-*
```
4、删除配置文件
```
rm -rf /etc/my.cnf
```
5、删除默认密码
```
rm -rf /root/.mysql_sercret
```

二、安装`mysql`

1、进入usr目录并且创建目录
```
cd /usr
mkdir soft
```

2、配置mysql的安装源

sudo rpm -Uvh https://dev.mysql.com/get/mysql80-community-release-el7-3.noarch.rpm

3、安装mysql

sudo yum --enablerepo=mysql80-community install mysql-community-server

4、启动mysql
```
sudo service mysqld start
```

5、查看状态

service mysqld status

[root@iZwz9et2qekjwu8mwmxgxhZ usr]# service mysqld status
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 Thu 2021-07-01 16:23:53 CST; 8s ago
     Docs: man:mysqld(8)
           http://dev.mysql.com/doc/refman/en/using-systemd.html
  Process: 1171 ExecStartPre=/usr/bin/mysqld_pre_systemd (code=exited, status=0/SUCCESS)
 Main PID: 1252 (mysqld)
   Status: "Server is operational"
   CGroup: /system.slice/mysqld.service
           └─1252 /usr/sbin/mysqld

Jul 01 16:23:44 iZwz9et2qekjwu8mwmxgxhZ systemd[1]: Starting MySQL Server...
Jul 01 16:23:53 iZwz9et2qekjwu8mwmxgxhZ systemd[1]: Started MySQL Server.
[root@iZwz9et2qekjwu8mwmxgxhZ usr]#

三、修改密码和远程登录配置

1、查看临时密码

grep "A temporary password" /var/log/mysqld.log

2、使用临时密码登录
```
mysql -uroot -p
```

3、修改数据库密码(直接修改这样的简单密码会报错的，因为密码策略的问题，必须包括:[大小写字母+数据+符号])

# 简单密码
ALTER USER 'root'@'localhost' IDENTIFIED BY '123456';
# 符合标准的密码
ALTER USER 'root'@'localhost' IDENTIFIED BY 'Aa@123456';

4、查看密码策略(要先修改密码才能执行)

SHOW VARIABLES LIKE 'validate_password.%';

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)

validate_password.length 是密码的最小长度，默认是8，我们把它改成6
```
set global validate_password.length=6;
```
validate_password.policy 验证密码的复杂程度，我们把它改成0
```
set global validate_password.policy=0;
```
validate_password.check_user_name 用户名检查，用户名和密码不能相同，我们也把它关掉
```
set global validate_password.check_user_name=off;
```

5、这时候可以修改为简单密码了(简单密码只适合玩玩的数据库密码，不适合生产项目)

6、配置远程可以登录

CREATE USER 'root'@'%' IDENTIFIED BY '123456';

7、刷新配置
```
FLUSH PRIVILEGES
```
8、直接在远程使用navicat连接

9、赋权限

# mysql8之前是这样的
GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' IDENTIFIED BY '123456' WITH GRANT OPTION;
# mysql8之后是这样的
grant all privileges on *.* to root@'%' with grant option;

10、补充内容，设置mysql开机启动

systemctl start mysqld
systemctl enable mysqld
systemctl daemon-reload

11、停止mysql

systemctl stop mysqld
# or 
service mysqld stop

四、使用`docker`安装`mysql8`

1、下载mysql
```
docker pull mysql
```

2、查看已经安装的mysql版本

docker image inspect mysql:latest | grep -i version

3、在宿主机创建放置mysql的配置文件的目录和数据目录，并且进行授权
```
mkdir -p /usr/mysql/conf /usr/mysql/data
chmod -R 755 /usr/mysql/
```

4、创建配置文件

vim /usr/mysql/conf/my.cnf

[client]

#socket = /usr/mysql/mysqld.sock

default-character-set = utf8mb4

[mysqld]

#pid-file        = /var/run/mysqld/mysqld.pid

#socket          = /var/run/mysqld/mysqld.sock

#datadir         = /var/lib/mysql

#socket = /usr/mysql/mysqld.sock

#pid-file = /usr/mysql/mysqld.pid

datadir = /usr/mysql/data

character_set_server = utf8mb4

collation_server = utf8mb4_bin

secure-file-priv= NULL

# Disabling symbolic-links is recommended to prevent assorted security risks

symbolic-links=0

# Custom config should go here

!includedir /etc/mysql/conf.d/

5、启动容器(注意是一行的)

docker run --restart=unless-stopped -d --name mysql -v /usr/mysql/conf/my.cnf:/etc/mysql/my.cnf -v 
/usr/mysql/data:/var/lib/mysql -p 3306:3306 -e MYSQL_ROOT_PASSWORD=123456 mysql

6、查看启动的容器
```
docker ps -a
```

7、进入容器中赋权远程连接

# 进入容器
docker exec -it mysql /bin/bash
# 进入mysql
mysql -uroot -p
# 修改权限
grant all privileges on *.* to root@'%' with grant option;
# 最后别忘记刷新
FLUSH PRIVILEGES

8、在容器中创建一个数据库，在客户端连接是否可以看到新的数据库
```
create database docker_test;
```

详解centos系统安装mysql8

一、准备工作

二、安装mysql

三、修改密码和远程登录配置

四、使用docker安装mysql8

二、安装`mysql`

四、使用`docker`安装`mysql8`