I've seen SaltStack using /var/run
. The only problem is that you need root access to write into that directory, but let's say that you are going to run your process as a system daemon. SaltStack creates /var/run/salt
at the installation time and changes the owner to salt
so that later on it can be used without root privileges.
I also checked the Filesystem Hierarchy Standard and even though it's not really important so much, even they say:
System programs that maintain transient UNIX-domain sockets must place them in this directory.
Since named pipes are something very similar, I would go the same way.