reset mysql root password

.my.cnf

[client]
user=root
#host=127.0.0.1
socket=/var/run/mysqld/mysqld.sock
[server]
plugin-load-add = auth_socket.so

mysql5.md

sudo service mysql stop
sudo mkdir -p /var/run/mysqld
sudo chown mysql:mysql /var/run/mysqld
sudo mysqld_safe --skip-grant-tables

mysql

use mysql;
update user set authentication_string=PASSWORD("") where User='root';
update user set plugin="mysql_native_password";
flush privileges;

sudo service mysql start

mysql8.md

sudo service mysql stop
sudo mkdir -p /var/run/mysqld
sudo chown mysql:mysql /var/run/mysqld
sudo mysqld --skip-grant-tables

mysql

use mysql;
flush privileges;
ALTER USER 'root'@'localhost' IDENTIFIED BY '';
flush privileges;

sudo service mysql start