How to add a new jdbc interpreter to Zeppelin by editing its conf/interpreter.json file?
I believe you approach will work in new version 0.8.0. In 0.8.0 interpreter ID equals interpreter name.
In previous versions interpreters have unique ID and this maybe reason of your question.
Remember that Zeppelin server must be off while editing conf/interpreter.json
I successfully added a new JDBC interpreter to my preferred DB, by using the normal zeppelin UI. It works. My Zeppelin is running on a docker container on my machine. I noticed it added my interpreter configuration to /zeppelin/conf/interpreter.json file.
I extracted the piece of json that was inserted on the file, under interpreterSettings collection. I built a script that would programmatically add that json block to /zeppelin/conf/interpreter.json so that my container would start with that interpreter configured out of the box.
But after I run my script on a brand new Zeppelin container what happen is that:
 1) it works - the piece of json is successfully inserted into /zeppelin/conf/interpreter.json
 2) Zeppelin won't show my interpreter on its UI
What else must I do to programmatically add this interpreter to my Zeppelin container?