libvirt-coreos cluster provider

libvirt-coreos is a cluster provider for kubernetes that starts local VMs and
runs kubernetes on it.
Its goal is to provide a multi-machines environment to develop and test kubernetes.

The purpose is mostly the same as the vagrant provider but with a big focus on
efficiency. The vagrant cluster takes a long time to boot and consumes a huge
amount of disk space. libvirt-coreos aims at being cheaper. As a consequence,
libvirt-coreos allows to start bigger clusters with more minions than vagrant.

cluster/kubectl.sh

@@ -120,6 +120,11 @@ elif [[ "$KUBERNETES_PROVIDER" == "vagrant" ]]; then
   config=(
     "--kubeconfig=$HOME/.kubernetes_vagrant_kubeconfig"
   )
+elif [[ "$KUBERNETES_PROVIDER" == "libvirt-coreos" ]]; then
+  detect-master > /dev/null
+  config=(
+    "--server=http://${KUBE_MASTER_IP}:8080"
+  )
 fi
 
 echo "current-context: \"$(${kubectl} "${config[@]:+${config[@]}}" config view -o template --template='{{index . "current-context"}}')\"" >&2