I am trying patches you just released for magnum (git fetch git://git.openstack.org/openstack/magnum refs/changes/30/629130/9 && git checkout FETCH_HEAD)
I got same issues on proxy. In the old version I modified with the help of spyros the scripts under /usr/lib/python2.7/dist-packages/magnum/drivers/common/templates/kubernetes/fragments
because PROXY variables are not inherited                  
in /etc/sysconfig/heat-params PROXY E NO PROXY variables are present but we must modify configure-kubernetes-master.sh to force them                  
. /etc/sysconfig/heat-params
echo "configuring kubernetes (master)"
 _prefix=${CONTAINER_INFRA_PREFIX:-docker.io/openstackmagnum/}
export HTTP_PROXY=${HTTP_PROXY}
export HTTPS_PROXY=${HTTPS_PROXY}
export NO_PROXY=${NO_PROXY}
echo "HTTP_PROXY IS ${HTTP_PROXY}"
exporting the above variables when external network has a proxy, the master is installed but stack hangs creating kube master Resource Group

Regards

Ignazio