Fetch queries the mutable settings from the settings repository, deserializes them, merges them into a clone of the baseConfs representing the configuration file and environment variables state, and returns the fresh configuration instance as an appuc.Builder interface in addition to its visible settings (as an instance of the version-independent model.VisibleSettings struct).

New instantiates a settings Repo struct.

Update converts the version-independent mutable model.Settings instance into a version-dependent serializable settings instance for the last supported version, serializes them as JSON, and then stores them in the settings repository.

Repo represents the settings repository instance.