docker@default:~$ docker pull daocloud.io/library/ubuntu:trusty-20151028

docker@default:~$ docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
daocloud.io/library/ubuntu trusty-20151028 4b1e42b414f6 13 months ago 188 MB

docker@default:~$ docker run -i -t daocloud.io/library/ubuntu:trusty-20151028 /bin/bash

root@199576c575aa:/# whoami
root

docker@default:~$ docker container ls
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
047f762f1b95 daocloud.io/library/ubuntu:trusty-20151028 "/bin/bash" 25 seconds ago Up 25 seconds zealous_wiles