I've made a script that produces old-style command "templates" from new interface definitions in XML in the VyOS 2.0 style.
Generating templates to be fully compatible with the old backend is tricky business though, and a debug mode to help us spot problems would be nice.

https://github.com/vyos/vyos-1x/blob/current/scripts/build-command-templates

There should be a --debug=1 option that makes it print all directories and files being created and generated node.def contents.

Use Python's standard library getopt.