Last blog we installed centos7 on a virtual machine, so let's start installing the lnmp environment.

As before, switch to root privileges using the su command after entering the command line.

Configure the firewall first
CentOS 7.0 uses firewall as a firewall by default
1. Turn off firewall:

    systemctl stop firewalld.service #Stop firewall  
    systemctl disable firewalld.service #Disable firewall startup  

2. Turn off SELINUX:

vi /etc/selinux/config  

#SELINUX=enforcing #comment out  
SELINUX=disabled #increase  
: wq! #Save Exit  
setenforce 0 #Make the configuration take effect immediately

3. Install priorities and wget

yum install yum-priorities -y 
yum -y install wget

1. Install mysql

Download mysql source installation package

wget http://dev.mysql.com/get/mysql57-community-release-el7-8.noarch.rpm

Install mysql source

yum localinstall mysql57-community-release-el7-8.noarch.rpm 

Check that the MySQL source is installed successfully, and note the dots in the command.

yum repolist enabled | grep "mysql.-community."

Install mysql

yum install mysql-community-server

Start the mysql service, which may be slower due to different computer configurations.

systemctl start mysqld 

View MySQL startup status

 systemctl status mysqld

Start Up

systemctl enable mysqld 
systemctl daemon-reload

Look at the root local login password (this command will find out the default random password set by mysql, as shown below, my random password is t3E4woyyi=:Y)

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

Login to mysql with a random password (random passwords are more difficult to recognize, more than a few times, when I logged in I tried it twice because I read the wrong password)

mysql -u root -p 

Modify MySQL login password (be careful not to miss the semicolon, this is mysql's statement, use exit to exit after modification and login again)

SET PASSWORD FOR 'root'@'localhost'="Chen123456.";
exit;

Note: mysql5.7 installs the password security checking plug-in (validate_password) by default, and the default password checking policy requires that passwords must contain uppercase and lowercase letters, numbers, and special symbols, and must not be less than 8 digits in length.Otherwise ERROR 1819 (HY000) will be prompted: Your password does not satisfy the current policy requirements error, as follows:

ALTER USER 'root'@'localhost' IDENTIFIED BY 'MyNewPass4!'; 
set password for 'root'@'localhost'=password('MyNewPass4!'); 
The msyql environment variable allows you to view information about password policies:
mysql> show variables like '%password%'; 

If the above cannot be modified, the root can be modified using the following security mode:
Close Service
systemctl stop mysqld.service 
vi /etc/my.cnf 
Add skip-grant-tables under mysqld to save and exit startup service
systemctl start mysqld.service 
Mysql-u root returns without a password
use mysql 
update user set authentication_string=password('Root-123') where User='root' and Host='localhost'; 
flush privileges; 
exit; 
Vi/etc/my.cnf deletes a skip-grant-tables sentence, saves it, exits the mysql service and restarts it
systemctl restart mysqld.service 
Sign in again
mysql -u root -pRoot-123

If the following prompt appears for the operation:
You must reset your password using ALTER USER statement before executing this statement. 
Set the password again
set password = password('Root-123'); 

Open port 3306 (allow connection to mysql server from any host using user name root password Root-123456)

mysql>grant all on root.* to root@'%' identified by 'vmroot!@#456VMROOT';
mysql>FLUSH PRIVILEGES; 
mysql>exit; 

Open external access to firewall mysql 3306 port

firewall-cmd --zone=public --add-port=3306/tcp --permanent
firewall-cmd --reload

Configure the default encoding to utf8

vi /etc/my.cnf

Modify the /etc/my.cnf configuration file to add the encoding configuration under [mysqld], as follows:
[mysqld] 
character_set_server=utf8 
init_connect='SET NAMES utf8'

Default profile path:
Configuration file: /etc/my.cnf
Log file: /var/log//var/log/mysqld.log
Service startup script: /usr/lib/systemd/system/mysqld.service
socket file: /var/run/mysqld/mysqld.pid

If you want to use a firewall, the following methods are recommended:

Turn off firewall:

Install iptables firewall:

From the command line, enter the following to open the selinux configuration file:

sudo vi /etc/selinux/config

The modifications are as follows

cd /etc/nginx/conf.d/  

vim default.conf  

Change listen 80 to listen 81 

Then restart nginx