docker an't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' code example

Example 1: ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/tmp/mysql.sock' (2)

sudo chown -R _mysql:mysql /usr/local/var/mysql

sudo mysql.server start

Example 2: how to connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)

#/usr/sbin/mysqld --defaults-file=/etc/mysql/my.cnf --basedir=/usr --datadir=/var/lib/mysql --pid-file=/var/run/mysqld/mysqld.pid --socket=/var/run/mysqld/mysqld.sock