@ErisDS It depends on your OS/distribution: https://www.docker.io/gettingstarted/#h_installation
For Ubuntu it's just: `sudo apt-get install lxc-docker` for example.

If you want to build ghost locally (and not push it to a remote registry for sharing the image with a third party), you can name the image as you want (eg. omit <repo> and do `docker build -t whatever`).