Running LXC and Docker containers on a Jessie instance requires having memory cgroup support enabled.
Memory cgroups support requires editing /etc/default/grub and reboot:
- Add "cgroup_enable=memory swapaccount=1" to GRUB_CMDLINE_LINUX
- Run update-grub2
If these changes were made to the default Jessie image offered in Labs it would make setting up MediaWiki-Vagrant and/or Docker containers easier for everyone.