default my.cnf inside the mysql container

my.cnf

# cat my.cnf
# Copyright (c) 2014, 2015, Oracle and/or its affiliates. All rights reserved.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; version 2 of the License.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA

#
# The MySQL Community Server configuration file.
#
# For explanations see
# http://dev.mysql.com/doc/mysql/en/server-system-variables.html

[client]
port		= 3306
socket		= /var/run/mysqld/mysqld.sock

[mysqld_safe]
pid-file	= /var/run/mysqld/mysqld.pid
socket		= /var/run/mysqld/mysqld.sock
nice		= 0

[mysqld]
skip-host-cache
skip-name-resolve
user		= mysql
pid-file	= /var/run/mysqld/mysqld.pid
socket		= /var/run/mysqld/mysqld.sock
port		= 3306
basedir		= /usr
datadir		= /var/lib/mysql
tmpdir		= /tmp
lc-messages-dir	= /usr/share/mysql
explicit_defaults_for_timestamp

# Instead of skip-networking the default is now to listen only on
# localhost which is more compatible and is not less secure.
#bind-address	= 127.0.0.1

#log-error	= /var/log/mysql/error.log

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

# * IMPORTANT: Additional settings that can override those from this file!
#   The files must end with '.cnf', otherwise they'll be ignored.
#
!includedir /etc/mysql/conf.d/