mysql 7.3 debian create new user code example

Example 1: enable password in mysql root user in mysql 8

1. If you in skip-grant-tables mode in mysqld_safe:

mysql> UPDATE mysql.user SET authentication_string=null WHERE User='root';
mysql> FLUSH PRIVILEGES;
mysql> exit;

and then, in terminal:

$ mysql -u root

in mysql:
mysql> ALTER USER 'root'@'localhost' IDENTIFIED WITH caching_sha2_password BY 'yourpasswd';


2. Not in skip-grant-tables mode just in mysql:
mysql> ALTER USER 'root'@'localhost' IDENTIFIED WITH caching_sha2_password BY 'yourpasswd';

Example 2: create a sudo user in centos 7

Create a new user accoun: useradd username
Set the user password: passwd username
Add the new user to the sudo group: usermod -aG wheel username
su - username, then run, echo "username  ALL=(ALL) NOPASSWD:ALL" | sudo tee /etc/sudoers.d/username

Example 3: add user with sudoer centos

username ALL=(ALL) NOPASSWD:/usr/bin/du,/usr/bin/ping