SOLVED: Check for empty device note?

Help
1

Hello,

I’d like to set an alert rule depending on some string in the devices.notes.

The idea is to mark devices which are not always on (these have a “_NOTALWAYSON” in their device notes)
and add a condition to my “Device down” alert rule.
I don’t want to see any “Device down” alert for these, but any other alert for them,
when these are up. So ‘ignore’ or ‘disable’ is not an option for me.

I found out, that
%devices.notes !~ “_NOTALWAYSON” &&
does not work as I expected:

This statement is only true for devices that do have a device note, which does not contain “_NOTALWAYSON”.
It is not true for any empty ( null ) device notes (most of my devices don’t have one).

Is this a wanted behavior?

Can somebody give me a hint how to get around this?
How can I check for an empty “device note” (to include this into the alert rule condition)?

Thank you!

  • awaum
2

You can’t check for null fields like that. You need to use a macro:

Put this in config.php

$config['alert']['macros']['rule']['null_notes'] = "(notes IS NULL OR notes != '_NOTALWAYSON')";

Then add this to your rule: && %macros.null_notes = "1"

3

Works like a charm!
Thanks a lot for your help!

Best regards,

  • awaum