[Nut-upsuser] Plea for a more loquacious nut

[Charles Lepple]

On Dec 4, 2013, at 3:35 PM, Roger Price wrote:

> I would like nut to become more loquacious, and to log a much more complete report of its activity.  At present nut reports that its components have started operation but does not automatically log their activity when UPS's switch between OB and OL.  I believe that this under-reporting of important facts is too minimalist - it would be better for system administrators and for the nut support team if a much more complete report were available of all OB/OL activity by each component.

In principle, more logging sounds like a good idea. What syslog level adjustments would you propose?

> Looking at the source code, it seems that much of what is needed is already in place, but behind "if" conditions that ensure that little or nothing gets through.  Long ago I wrote software, including a compiler, but my C programming is limited to a class exercise many many years ago, and its based on this "experience" that I'm guessing that in upssched.c function exec_cmd the code
> 
>  snprintf(buf, sizeof(buf), "%s %s", cmdscript, cmd);
>  err = system(buf);
>  if (WIFEXITED(err)) {
> 	if (WEXITSTATUS(err)) {
> 		upslogx(LOG_INFO, "exec_cmd(%s) returned %d", buf, WEXITSTATUS(err));
> 	}
> 
> attempts to send a command to the operating system, possibly to execute a Bash script.  If system(buf) fails, the tests block the error message. Surely the error message is essential.  An unattended box is now in an emergency situation.  After the inevitable IT failure the system should be auditable to discover what went wrong and what should be done to prevent it happening in the future.  Such an audit expects to find "exec_cmd(%s) returned %d" in the log.

Are you looking for:

 * more diagnostics depending on the value of err,
 * logging of all return codes, even success

or both?

> "But these problems should be found by testing!", one might argue. Firstly, the testing would be facilitated by this error message, and secondly, no amount of testing will ever cover every situation met in the real world.
> 
> I believe nut would be improved by
> 
> 1. Logging a summary of the state of the nut system and the UPS's every 24 hours.

I would personally prefer that NUT didn't do this by default. (Then again, I don't do a lot of sysadmin work for critical systems, so take that with a grain of salt.) To me, this seems like a call to 'upsc' should be placed in a nightly cron job. If you have multiple UPSes, you can iterate over them. We could add an example script to the NUT source tree for that.

> 2. Automatically logging a record of driver, upsd, upsmon and upssched activity for each OB/OL change.

Fair point. I don't think logging at every single point is necessary, but if it's configurable, that would work.

> 3. Replacing the upsmon NOTIFYFLAG "SYSLOG" by "NOSYSLOG".  All notifications are logged unless the sysadmin explicitly calls for no logging.


I suspect I am missing something here. The default upsmon.conf logs everything to syslog (and wall) by default. Unless that part is broken (and I confess I haven't thoroughly tested it recently), wouldn't the defaults work without breaking existing installations? I agree that it is better to err on the side of logging more information, but I don't think we need to break the existing syntax to do that.

If anything, I would want finer-grained control over the syslog level for some of these events.

-- 
Charles Lepple
clepple at gmail