Add an advertise-address flag. This allows the address that the apiserver binds

to (possibly 0.0.0.0) to be different than the address on which members of the cluster
can reach the apiserver (possibly not a local interface).

cluster/gce/configure-vm.sh

@@ -496,6 +496,7 @@ project-id = ${PROJECT_ID}
 EOF
     cat <<EOF >>/etc/salt/minion.d/grains.conf
   cloud_config: /etc/gce.conf
+  advertise_address: '${KUBERNETES_MASTER_NAME}'
 EOF
   fi
 }