Kubernetes exposes DNS for service discovery, but the DNS server itself must be configured after you install Kubernetes. In the future it will be integrated into
kubernetes as part of the platform (see PR11599) but for now you have to setup and run the SkyDNS container yourself.
I have seen some tutorials on how to get
skydns working, but almost all of them are rather involved. However, if you just want a simple setup on a single node for testing then it is actually rather easy to get
skydns set up.