Change SNMP LLD values

[derdeagle]

When using LLD via SNMP a JSON like the following is returned (modified because the log didn't show the full string).

[
    {
      "{#SNMPINDEX}":"14",
      "{#FAN}":"temperature"
   },
   {
      "{#SNMPINDEX}":"17",
      "{#FAN}":"cpu-temperature"
   },
   {
      "{#SNMPINDEX}":"20",
      "{#FAN}":"fan1-speed"
   },
   {
      "{#SNMPINDEX}":"21",
      "{#FAN}":"fan2-speed"
   },
   {
      "{#SNMPINDEX}":"22",
      "{#FAN}":"fan3-speed"
   },
   {
      "{#SNMPINDEX}":"23",
      "{#FAN}":"fan4-speed"
   }
]​

I only want the fans to be returned, so I added a filter filtering "{#FAN} = ^fan[0-9]+-speed$". That work's as expected.
What I could not achieve by trying out myself or search on the forum etc. was changing the name from e.g. "fan1-speed" to "Fan 1".
How can I change those LLD macro values?

Thanks in advance.

[markfree]

There's a catch with item keys.

Note, that commas are not allowed in unquoted item key parameters, so the parameter containing a macro function has to be quoted. The backslash (\) character should be used to escape double quotes inside the parameter.

Try it like this:

fan.speed["fan{{#FAN}.regsub(\"fan([0-9]+)-speed\",\1)}"]

Do you really find it necessary to extract the fan number to use it at the key parameter? Wouldn't the macro value itself be enough?

[markfree]

Macro functions could be helpful for your discovery.

What if you tried something like this?

{{#FAN}.regsub("fan([0-9]+)-speed",\1)}

In my testing, I managed to extract the number from an LLD macro value and use it in the name field.

[derdeagle]

Your suggested way indeed works for the name but unfortunately not for the key.
I was able to set the name to the following value:

Fan {{#FAN}.regsub("fan([0-9]+)-speed",\1)} speed

If I now want to set the key to the following value I get the error message afterwards:

fan.speed[fan{{#FAN}.regsub("fan([0-9]+)-speed",\1)}]

Invalid key "fan.speed[fan{{#FAN}.regsub("fan([0-9]+)-speed",\1)}]" for item prototype "Fan {{#FAN}.regsub("fan([0-9]+)-speed",\1)} speed" on "Template Mikrotik CCR2116-12G-4Splus": incorrect syntax near "+)-speed",\1)}]".

According to the fine manual the macro function should also work in the key.

Btw. I am using version 6.0.9 if that is of interest.

[markfree]

There's a catch with item keys.

Note, that commas are not allowed in unquoted item key parameters, so the parameter containing a macro function has to be quoted. The backslash (\) character should be used to escape double quotes inside the parameter.

Try it like this:

fan.speed["fan{{#FAN}.regsub(\"fan([0-9]+)-speed\",\1)}"]

Do you really find it necessary to extract the fan number to use it at the key parameter? Wouldn't the macro value itself be enough?

[Markku]

Do you really find it necessary to extract the fan number to use it at the key parameter? Wouldn't the macro value itself be enough?

I would definitely keep the original string that was present in the discovery data, that will help hugely when someone looks at the items and the discovery data later. Just my 2 cents

Markku

[derdeagle]

That is now working as intended, thank you very much.

There's a catch with item keys.
[...]
Do you really find it necessary to extract the fan number to use it at the key parameter? Wouldn't the macro value itself be enough?

It is not necessary at all and both if you are 100% right. This should not be done in general. As this is solely for me privately let's just declare it as learning Nevertheless I do think about just using the value (fan1-speed) as the key as this will be unique, too.