ERROR 1698 (28000): Access denied for user 'root'@'localhost'

Question

I\'m setting up a new server and keep running into this problem.

When I try to login to the MySQL database with the root user, I get the error:

Answer 1

os:Ubuntu18.04

mysql:5.7

1. add the skip-grant-tables to the file end of mysqld.cnf

2. cp the my.cnf

sudo cp /etc/mysql/mysql.conf.d/mysqld.cnf /etc/mysql/my.cnf

2. reset the password

(base) ➜  ~ sudo service mysql stop 
(base) ➜  ~ sudo service mysql start
(base) ➜  ~ mysql -uroot
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.7.25-0ubuntu0.18.04.2 (Ubuntu)

Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> use mysql
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Database changed, 3 warnings
mysql> update mysql.user set authentication_string=password('newpass') where user='root' and Host ='localhost';
Query OK, 1 row affected, 1 warning (0.00 sec)
Rows matched: 1  Changed: 1  Warnings: 1

mysql> update user set plugin="mysql_native_password"; 
Query OK, 0 rows affected (0.00 sec)
Rows matched: 4  Changed: 0  Warnings: 0

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

mysql> quit
Bye

3. remove theskip-grant-tables from my.cnf

(base) ➜  ~ sudo emacs /etc/mysql/mysql.conf.d/mysqld.cnf 
(base) ➜  ~ sudo emacs /etc/mysql/my.cnf                 
(base) ➜  ~ sudo service mysql restart

4. open the mysql

(base) ➜  ~ mysql -uroot -ppassword 
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 3
Server version: 5.7.25-0ubuntu0.18.04.2 (Ubuntu)

Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> 

5. check the password policy

mysql> select @@validate_password_policy;
+----------------------------+
| @@validate_password_policy |
+----------------------------+
| MEDIUM                     |
+----------------------------+
1 row in set (0.00 sec)


mysql> SHOW VARIABLES LIKE 'validate_password%';
+--------------------------------------+--------+
| Variable_name                        | Value  |
+--------------------------------------+--------+
| validate_password_dictionary_file    |        |
| validate_password_length             | 8      |
| validate_password_mixed_case_count   | 1      |
| validate_password_number_count       | 1      |
| validate_password_policy             | MEDIUM |
| validate_password_special_char_count | 1      |
+--------------------------------------+--------+
6 rows in set (0.08 sec)！

6. change the config of the validate_password

mysql> set global validate_password_policy=0;
Query OK, 0 rows affected (0.05 sec)

mysql> set global validate_password_mixed_case_count=0;
Query OK, 0 rows affected (0.00 sec)

mysql> set global validate_password_number_count=3;
Query OK, 0 rows affected (0.00 sec)

mysql> set global validate_password_special_char_count=0;
Query OK, 0 rows affected (0.00 sec)

mysql> set global validate_password_length=3;
Query OK, 0 rows affected (0.00 sec)

mysql> SHOW VARIABLES LIKE 'validate_password%';
+--------------------------------------+-------+
| Variable_name                        | Value |
+--------------------------------------+-------+
| validate_password_dictionary_file    |       |
| validate_password_length             | 3     |
| validate_password_mixed_case_count   | 0     |
| validate_password_number_count       | 3     |
| validate_password_policy             | LOW   |
| validate_password_special_char_count | 0     |
+--------------------------------------+-------+
6 rows in set (0.00 sec)

note you should know that you error caused by what? validate_password_policy?

you should decided to reset the your password to fill the policy or change the policy.