Centos7 installs MySQL 8 database
(yum, the default interpreter is python2.7, don't change Python soft connection)
mkdir /data mkdir /data/mysql cd /data/mysql wget https://dev.mysql.com/get/mysql80-community-release-el7-2.noarch.rpm yum -y install mysql80-community-release-el7-2.noarch.rpm yum -y install mysql-community-server
If it is centos8, an error will be generated because there is a MySQL module locally. At this time, you can disable the module before trying to install:
yum module disable mysql
MySQL installation acceleration
If Yum - y install MySQL community server installation is extremely slow, you can take the following measures.
Downloaded cache path:
/var/cache/yum/x86_64/7/mysql80-community/packages
Use sftp tool to upload the complete package corresponding to the directory to this path, and then re execute the installation instruction.
Go to the image resource station to download (choose one)
Copy the name in the cache directory, search (usually the largest MySQL community server), download it, and upload it to the cache directory.
MySQL installation error
Note that the following errors generally do not occur. In case of errors, it is recommended to recheck the download package and server.
After downloading, if you encounter errors during installation, the following are reported:
Error: GPG check FAILED
Generally, dnf or yum software installation fails due to source key error.
Try adding the – nogpgcheck suffix to ignore and re execute the installation:
yum -y install mysql-community-server --nogpgcheck
Start database
systemctl start mysqld.service
Modify the initial password of the database
Get initial password:
grep "password" /var/log/mysqld.log
Execute the following instructions and enter the default password to enter mysql
mysql -u root -p
To change the password, take passwd as an example:
ALTER USER 'root'@'localhost' IDENTIFIED BY 'passwd';
Uninstall yum repository
yum -y remove mysql80-community-release-el7-2.noarch
mysql database is open to the public
use mysql; update user set host = '%' where user = 'root'; select host, user from user; flush privileges;
Modify mysql password strength
View password rules
SHOW VARIABLES LIKE 'validate_password%';
Set password strength
set global validate_password.policy=0; set global validate_password.length=4;
That is, the password only needs to meet four characters (do not repeat with the user name)
View mysql code
show variables like '%set%';
Centos7 installing python3
Installation dependency
View gcc version
gcc --version
Not installed
yum -y install gcc
Installation dependency (important!)
yum -y install zlib-devel bzip2-devel openssl-devel ncurses-devel sqlite-devel readline-devel tk-devel gdbm-devel db4-devel libpcap-devel xz-devel libffi-devel
setup script
Create a folder to store Python 3
mkdir /usr/local/python3.9
Download the specified version of python to the local
Manual Download:
Automatic download:
wget https://www.python.org/ftp/python/3.9.9/Python-3.9.9.tgz
Download the package to linux, taking / data as an example
cd /data tar -zxvf Python-3.9.9.tgz cd Python-3.9.9.tgz ./configure --prefix=/usr/local/python3.9 make && make install
Establish a soft connection (do not replace the default python!)
If you enter Python and enter the 2.7 environment by default, please do not change the soft connection of python, which will cause inexplicable errors in centos.
In fact, the system environment variable of Python should be established here, not just a soft link. But centos has installed python2 by default, so only a soft link is established here.
If the soft connection already exists, use rm to delete it.
ln -s /usr/local/python3.9/bin/python3.9 /usr/bin/python3 ln -s /usr/local/python3.9/bin/pip3.9 /usr/bin/pip3
Establish pip soft connection
ln -s /usr/bin/pip3 /usr/bin/pip
View established soft connections
ls -il /usr/bin/pip
Python creates virtualenv virtual environment
install
pip install virtualenv
View version
virtualenv --version
Enter virtual environment
Go to the directory to be created and create the environment (venv can be changed to its own name)
virtualenv venv
Activate environment
source venv/bin/activate
Exit environment
deactivate
Other related commands:
View the current virtual machine environment directory
worken
Switch virtual environment
workon venv2
Exit virtual environment
deactivate
Delete virtual environment
rmvirtualenv venv
Python installation requirements Txt dependency
Generate project dependencies
pipreqs ./ --encoding=utf8
Installation project dependency
Add requirements Txt copy to the project directory and install
pip install -r requirements.txt