Docker, user-docker and system-docker strange behavior

When I boot from the iso, the following commands give the following result which I do not understand:

docker command: works
FATA[0000] remove /var/lib/rancher/engine/docker: permission denied

[rancher@rancher ~]$ sudo user-docker
FATA[0000] open /engine: no such file or directory

[rancher@rancher ~]$ docker
-bash: /bin/docker: No such file or directory

system-docker: works perfectly

SO, I don’t get it: if you try running user-docker it will remove your ability to run the “normal” docker and won’t run anyway but once you run system-docker you still won’t be able to run user-docker?

user-docker is a command designed to be used behind the scenes and not for general usage. It’ll be hidden in v0.8.0 and future releases.

aah, thanks now I get it