Showing global_tags variable in Grafana SingleStat

I’m fairly new to telegraf/Grafana so bare with me please.
I have some SingleStat panels that run a command in [[inputs.exec]] to get rpm version numbers etc for my dashboard. One thing I would also like to add is the get the version number of the telegraf.conf file. I have added to my file:
telegraf_version = “1.1”

What is the best way to get this onto my Dashboard? I have tried a variable (which returns 1.1 when tested) but can’t get that to display anything but N/A when I try put it in a SingleStat. Is there a better way or should I just use “sh -c 'grep -i etc…” in an [[inputs.exec]]?

Using Grafana v5.2.2 (not my choice…)

Thank you