问题:

I think this is better:

sudo apt-get install docker

But why didn't choose a clearly name?

回答1:

http://blog.docker.com/2014/04/docker-in-ubuntu-ubuntu-in-docker/

Why do Ubuntu use docker-engine as executable name instead of just docker? Tutorials, blog posts all now have to mention this difference, “if you use Ubuntu 14.04, or if you are with rest of the world (including earlier versions of Ubuntu)”. Why?

This is because of a Debian/Ubuntu policy; there is already a program called “docker” [1], and it was not allowed to use the same binary name.

Full installation instructions for the most-recent version are at https://docs.docker.com/engine/installation/linux/ubuntulinux/.

回答2:

issue this to install docker on ubuntu for your development boxes

curl -sSL https://get.docker.com/ | sh -y

if you want very latest dev release then issue

curl -fsSL https://test.docker.com/ | sh

when running either of above you will notice this walks through the same steps as listed in canonical docker install doc https://docs.docker.com/engine/installation/linux/ubuntulinux/ which is very handy when installing docker on remote servers and should be used for production boxes