This is resin.io's Supervisor, a program that runs on IoT devices and has the task of running user Apps (which are Docker containers), and updating them as Resin's API informs it to.
This Bookshelf.js plugin enables you to define masks on your models and serialize to JSON based on its fields using the json-mask API. It is based on bookshelf-mask, but it allows you to specify an array of scopes instead of just one.