Don't send metrics with no value in nagios perfdata

[flyingflo]

At least icinga2's GraphiteWriter fails to parse perfdata without values and spams the log with error messages like:

Ignoring invalid perfdata for checkable 'host1!ntpmon' and command 'ntpmon' with value: tracehosts=

Anyways, I'm not sure how other consumers of this data behave.

[paulgear]

Thanks for that - are any of the other metrics other than tracehosts which show up like this?

[flyingflo]

Thanks for that - are any of the other metrics other than tracehosts which show up like this?

Yes, all trace* metrics, because this check is disabled by default. If I disable other checks, their metrics are also reported without value and cause such a warning.

[paulgear]

Thanks for that - are any of the other metrics other than tracehosts which show up like this?

Yes, all trace* metrics, because this check is disabled by default. If I disable other checks, their metrics are also reported without value and cause such a warning.

Thanks. I don't think enough people rely on this package to worry about breaking backwards compatibility, and this is getting in the way of your deployment. I'll tag this as a new minor release hopefully this weekend.

[flyingflo]

Thank you, Paul!