if there are "non-authorized packages" errors during building ros-kinetic image, adding the following to the Dockerfile might help -- there's another line loading keys, right after that :
RUN apt-key adv --keyserver 'hkp://keyserver.ubuntu.com:80' --recv-key C1CF6E31E6BADE8868B172B4F42ED6FBAB17C654
if there are "non-authorized packages" errors during building ros-kinetic image, adding the following to the Dockerfile might help -- there's another line loading keys, right after that :