Custom Onboarding Extension with TextFSM

[jeffkala]

When you're creating your own onboarding extension that is using TextFSM its important to know how the case sensitivity works.

The onboarding parsing type is textfsm, which in reality uses ntc-templates behind the scenes, more specifically commands are parsed using the ntc-templates parse method. This method will lowercase all the parsed data keys.
https://github.com/networktocode/ntc-templates/blob/0cb018ab1e96a748969b2231c33bf651dd7483a8/ntc_templates/parse.py#L37

So why does it matter?

Well Jmespath search which is used by Jdiff in this implementation is case sensitive. So just because you look at the template in ntc-templates repo and the key is named INTERFACE in your jpath definition you must realize that it will be lowercased behind the scenes. So make sure your jpath is lowercased for the key calls.