kubernetes autoscale fails to get metrics (heapster already installed in kube-system namespace)
Ok I found the solution, my cluster was flawed. I had to install flannel on the master too. With the option --iface=eth1 because of vagrant.
I followed this guide http://severalnines.com/blog/installing-kubernetes-cluster-minions-centos7-manage-pods-services but they didnt say to install flannel on the master.
Now everything is working.