Can't connect to local MySQL server through socket '/tmp/mysql.sock' (2)

[nikolocalhost]

Bueno, lo primero que tienes que hacer es verificar si el sevidor MySQL efectivamente esta corriendo sobre el socket '/tmp/mysql.sock'

Para eso, abres el archivo /etc/my.cnf
y debes hallar algo asi:

[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
user=mysql
# Default to using old password format for compatibility with mysql 3.x
# clients (those using the mysqlclient10 compatibility package).
old_passwords=1

# To allow mysqld to connect to a MySQL Cluster management daemon, uncomment
# these lines and adjust the connectstring as needed.
#ndbcluster
#ndb-connectstring="nodeid=4;host=localhost:1186"

[mysqld_safe]
log-error=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid

[ndbd]
# If you are running a MySQL Cluster storage daemon (ndbd) on this machine,
# adjust its connection to the management daemon here.
# Note: ndbd init script requires this to include nodeid!
connect-string="nodeid=2;host=localhost:1186"

[ndb_mgm]
# connection string for MySQL Cluster management tool
connect-string="host=localhost:1186"

[client]
socket=/var/lib/mysql/mysql.sock

Eso ultimo es lo que te va a permitir conectarte por el socket correcto, probablemente no tengas las lineas en rojo, solo agregalas y reinicia el servidor MySQL.

Seguro te funciona :)