Cant't access mysql.sock (running on a jail) from a separate jail

[Miroslav Lachman]

Manolis Tzanidakis wrote:
> Hello all,
> maybe this is already answered, but searching the list's archives
> was not working at the moment.
>
> Anyway, I've got a server running 8.0-RELEASE with various
> jails, all setup with ezjail. One jail is running mysql and another
> is running apache.
> I have a directory /usr/jails/mysqltmp (owned by mysql:mysql)
> on the host system, which is mounted in both jails as /mysqltmp  with:
>
> /etc/fstab.mysqljail:
> /usr/jails/mysqltmp /usr/jails/mysqljail/mysqltmp nullfs rw 0 0
>
> /etc/fstab.apachejail:
> /usr/jails/mysqltmp /usr/jails/mysqlapache/mysqltmp nullfs ro 0 0
> (tried it also with 'rw', same results)
>
> I've setup my.cnf in mysqljail to write the mysql.sock socket in
> /mysqltmp and I can access mysql from this jail without problems,
> as expected.
> On the apachejail the socket shows up in /mysqltmp, however I can't
> connect:
>
> # mysql -S /mysqltmp/mysql.sock -u root -p
> ERROR 2002 (HY000): Can't connect to local MySQL server through
> socket '/mysqltmp/mysql.socket' (2)

You can use hardlink if you have your jails on one filesystem, or you 
can try unionfs instead of nullfs.

Miroslav Lachman