Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock'

[lmakarov]

mysql (client) and mysqladmin throw socket connection error when trying to connect from localhost:

[root@db /]# mysql
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)

[root@db /]# mysqladmin ping
mysqladmin: connect to server at 'localhost' failed
error: 'Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)'
Check that mysqld is running and that the socket: '/var/lib/mysql/mysql.sock' exists!

[lmakarov]

The cause of this is that mysql:8.0-oracle upstream image does not define the socket in the client section of the my.cnf config:

[root@db /]# cat /etc/my.cnf
# For advice on how to change settings please see
# http://dev.mysql.com/doc/refman/8.0/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

# Remove leading # to revert to previous value for default_authentication_plugin,
# this will increase compatibility with older clients. For background, see:
# https://dev.mysql.com/doc/refman/8.0/en/server-system-variables.html#sysvar_default_authentication_plugin
# default-authentication-plugin=mysql_native_password
skip-host-cache
skip-name-resolve
datadir=/var/lib/mysql
socket=/var/run/mysqld/mysqld.sock
secure-file-priv=/var/lib/mysql-files
user=mysql

pid-file=/var/run/mysqld/mysqld.pid

!includedir /etc/mysql/conf.d/

We will have to manually add this in the configuration overrides in this image:

[client]
socket = /var/run/mysqld/mysqld.sock