[CFT] multiple instance support in rc.d script

[Jim Riggs]

On 16 Oct 2014, at 20:22, Hiroki Sato <hrs at FreeBSD.org> wrote:

> I would like your feedback and testers of the attached patch.  This
> implements multiple instance support in rc.d scripts.  You can try it
> by replacing /etc/rc.subr with the attached one.


I really like the idea, as I have written at least 2 or 3 ports in which I have needed support for multiple "profiles" (as I have seen them called in several ports). So, I had to duplicate the multiple-instance logic in the rc script for each. This would save all of that aggravation.

The only concern I have with generalizing the approach in rc.subr, though, is that not every app/daemon/script can or should support it. I worry that some things if run multiple times may stomp on each other or corrupt data or break something. It seems that there should be a way for each rc script to either opt in or opt out of multiple instance support. I don't know which is better. Opt-in is probably safer, but then core devs and port maintainers have to make specific changes to support it. :-\

Thoughts?