centos6.5加epel后,怎么无法搜到docker-io呢?

yum search docker
Loaded plugins: fastestmirror===================================================================== N/S Matched: docker ============================================================================================================
python-docker-registry-core.noarch : Core package for docker-registry (drivers) developers
docker-registry.noarch : Registry server for Docker
golang-github-fsouza-go-dockerclient-devel.i686 : Client for the Docker remote API
docker.i686 : KDE and GNOME2 system tray replacement docking application

加epel还不够么?还需要加啥呢?