We are just a few days away from creating the Juniper release branches (open-release/juniper.master) in the relevant repos. Up until now, and still for a few days, everything being committed to master is part of Juniper. Once the Juniper branches are created, changes will have to be cherry-picked to be part of Juniper.
Docker and old VM based solutions are really inconvenient to maintain :\ - I’ve got some ideas about replacing the configuration repository, but really need support for newer Ubuntu versions to make them possible.