[Nut-upsdev] feature request -- talk to the router, not the UPS

[Charles Lepple]

On Jun 2, 2014, at 7:27 AM, elliot smith wrote:

> For example I am using FreeNAS.  Rather than supporting my unorthodox UPS
> signaling scheme by installing it as a script in FreeNAS, (and me probably
> messing something up in the process) this scheme could be supported
> instead by NUT.

Bear in mind that all of the NUT drivers have authors who are expected to be maintainers of that driver. Are you volunteering?

> For the port, when I'm configuring my "UPS" settings in
> the FreeNAS GUI, instead of specifying one of the USB ports, I would
> specify the TCI/IP port, with the IP of the device to ping.

Are you referring to an ICMP ping here? Some OSes require root privileges to open a raw socket to send the ping echo-request, and NUT is designed to drop root privileges when a driver starts.

Alternatively, you could call out to the system's ping binary. I haven't checked, but I suspect this would require a bunch of options to handle various command line options and return codes.

You could also have an option for a TCP or UDP "ping" to some service on whatever device you are trying to contact, but I think this explosion of options points to some sort of scripting solution coupled with an existing driver.

Note that we are happy to include these sorts of scripts in NUT.

> On Mon, June 2, 2014 2:50 am, Ted Mittelstaedt wrote:
> 
>> That kind of scheme should be handled by scripting - not by NUT.
>> 
>> As far as having a _perfectly good UPS with no driver_, ANY UPS can
>> be converted into a "dumb" UPS with the addition of 2 relays.

There was also this discussion last summer (similar to Ted's printer idea, but lower power):

http://news.gmane.org/find-root.php?message_id=20130703045347.55D4172182%40mail.gishpuppy.com

I'm not a huge fan of polling when edge-triggered events are available. (That said, dummy-ups polls its state file once a second, and that could be improved upon with something like inotify.)

In most cases, you can add a devd (FreeBSD) or udev (Linux) rule that triggers when a device disappears, without affecting normal operation of that device while it is connected. Both devd and udev will simply run all of the matching rules when the specified action occurs.

-- 
Charles Lepple
clepple at gmail