Knowledge Base

Messages about failed logrotate task are received in Plesk on Ubuntu 18 or Debian 9: ‘Access denied for user ‘root’@’localhost’ (using password: NO)

Symptoms

Plesk administrator receives messages about failed logrotate tasks:

/etc/cron.daily/logrotate:
mysqladmin: connect to server at 'localhost' failed
error: 'Access denied for user 'root'@'localhost' (using password: NO)'
error: error running shared postrotate script for '/var/log/mysql/mysql.log /var/log/mysql/mysql-slow.log /var/log/mysql/mariadb-slow.log /var/log/mysql/error.log '
run-parts: /etc/cron.daily/logrotate exited with return code 1

Cause

Plesk bug with ID #PPPM-8915 fixed in:

Plesk Onyx 17.8 25 March 2019
Plesk Obsidian 28 August 2018 (fixed as PPP-37427, Linux)

Resolution

Install Plesk updates

In case Plesk updates can not be installed, following workaround can be applied in Debian based operating systems:

Create a MySQL root user

Connect to the server via SSH
Create a backup of the initial configuration file:

# cp -a /etc/mysql/debian.cnf /root/debian.cnf
Create MySQL database backup:

# MYSQL_PWD=`cat /etc/psa/.psa.shadow` mysqldump -u admin mysql > "mysql`date +%F_%H.%M`.sql"
Access MySQL:

# plesk db
Create MySQL user root with password:

GRANT RELOAD, SHUTDOWN, PROCESS, SHOW DATABASES, SUPER, LOCK TABLES ON *.* TO 'root'@'localhost' IDENTIFIED BY 'your_password';
Exit MySQL:

exit;
Modify /etc/mysql/debian.cnf and specify user with password created above:

[client]
host = localhost
user = root
password = "your_password"
socket = /var/run/mysqld/mysqld.sock
[mysql_upgrade]
host = localhost
user = root
password = "your_password"
socket = /var/run/mysqld/mysqld.sock
basedir = /usr
Make sure that logrotate works. If the command doesn't show the output then everything works properly:

# mysqladmin --defaults-file=/etc/mysql/debian.cnf --local flush-error-log