Fix Galera socket for RedHat

combined backport of :
- https://review.openstack.org/#/c/529880/
- https://review.openstack.org/#/c/529879/

Change-Id: I30e2f9bd17e69dfd5f7d47fc2678faf3388ca5af

templates/my.cnf.j2

@@ -10,11 +10,11 @@
 
 [client]
 port = 3306
-socket = /var/run/mysqld/mysqld.sock
+socket = "{{ galera_var_run_socket }}"
 
 
 [mysqld_safe]
-socket = /var/run/mysqld/mysqld.sock
+socket = "{{ galera_var_run_socket }}"
 nice = 0
 log_error = /var/log/mysql_logs/galera_server_error.log
 

vars/redhat-7.yml

@@ -29,6 +29,7 @@ galera_server_required_distro_packages:
   - MariaDB-devel
   - xinetd
 
+galera_var_run_socket: "/var/lib/mysql/mysql.sock"
 _galera_mariadb_server_package: "MariaDB-server"
 
 galera_server_mariadb_distro_packages:

vars/ubuntu-16.04.yml

@@ -40,6 +40,7 @@ galera_server_required_distro_packages:
   - software-properties-common
   - xinetd
 
+galera_var_run_socket: "/var/run/mysqld/mysqld.sock"
 # The package name for mariaDB is set as a variable
 # so that it can be used in debconf later in the
 # "galera_common" role.