Knife diff nodes behaviour


I want to use knife diff for monitoring and reporting differencce between my repository (managed by git) and my chef server.

I use report done by knife diff, and it’s working nicely for environments and roles.

Therefore the behaviour for nodes diff is strange.
My repository contains json file for each nodes, containing basically the output of the command knife node show <node> -F json, therefore the knife diff command seems to use the long output to get chef server node informations which contains ohai parameters.
As result, all nodes are always listed as not identical between my repository and the server.

Is it the normal behaviour ? How should I monitor my repository ?

From IRC chat, I will test knife-inspect