[root@slave1 mysql57]# cat /var/log/mysqld.log |grep password
2022-02-03T09:59:22.090885Z 1 [Note] A temporary password is generated for root@localhost: AJDtlg*kM1W1

# For advice on how to change settings please see
# http://dev.mysql.com/doc/refman/5.7/en/server-configuration-defaults.html

[mysqld]
#
# Remove leading # and set to the amount of RAM for the most important data
# cache in MySQL. Start at 70% of total RAM for dedicated server, else 10%.
# innodb_buffer_pool_size = 128M
#
# Remove leading # to turn on a very important data integrity option: logging
# changes to the binary log between backups.
# log_bin
#
# Remove leading # to set options mainly useful for reporting servers.
# The server defaults are faster for transactions and fast SELECTs.
# Adjust sizes as needed, experiment to find the optimal values.
# join_buffer_size = 128M
# sort_buffer_size = 2M
# read_rnd_buffer_size = 2M
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock

# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0

log-error=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid
validate_password=OFF #新添加

登录mysql
mysql -uroot -p回车输入/var/log/mysqld.log中的密码

设置密码（需要关闭密码验证插件validate_password=OFF）
set password for root@localhost=password('123456');

查看mysql现有账号
use mysql;
mysql> select user,host from user;
+---------------+-----------+
| user          | host      |
+---------------+-----------+
| mysql.session | localhost |
| mysql.sys     | localhost |
| root          | localhost |
+---------------+-----------+
3 rows in set (0.00 sec)

添加远程账号

mysql> grant all privileges on *.* to root@'%' identified by 'admin888';
Query OK, 0 rows affected, 1 warning (0.00 sec)

mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)

centos添加3306端口
[root@slave1 mysql57]# firewall-cmd --zone=public --add-port=3306/tcp --permanent
success
[root@slave1 mysql57]# firewall-cmd --reload
success