Since an update to the Samba and latest HA, there is an issue with the way you address save and read your json files.
With a little help and a lot of experimentation I have discovered the correct way of addressing files generated in Nodered and reading them in HA.
Here are the details in brief
Here is the proceedure:-
1 The mapping in config is a must
map:
- addon_config:rw
- homeassistant_config:rw
- media:rw
- share:rw
- www:rw
- local:rw
- ssl
2 Nodered write file has to be /homeassistant/www/community/myfolder/myfile.x
3 The REST resource url has to be http://192.168.1.130:8123/local/community/myfolder/myfile.x