I think this is documented as not working when you are using systemd in the file itself:
$ cat /etc/default/docker $ head -8 /etc/default/docker # Docker Upstart and SysVinit configuration file # # THIS FILE DOES NOT APPLY TO SYSTEMD # # Please see the documentation for "systemd drop-ins": # https://docs.docker.com/engine/admin/systemd/ # -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1832819 Title: docker.io in disco can't change config in /etc/default/docker To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/docker.io/+bug/1832819/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs