ClusterFromBytes Necessary for unit tests, which store configs as hardcoded strings.

Part of configuration which can't be provided via user input but is computed from user input.

Part of configuration which is specific to controller nodes.

Part of configuration which is specific to worker nodes.

Part of configuration which can be customized for each type/group of nodes(etcd/controller/worker/) by its nature.

The fact KMS encryption produces different ciphertexts for the same plaintext had been causing unnecessary node replacements(https://github.com/kubernetes-incubator/kube-aws/issues/107) Persist encrypted assets for caching purpose so that we can avoid that.

Part of configuration which is specific to etcd nodes.

Part of configuration which is specific to flanneld.

Part of configuration which is shared between controller nodes and worker nodes.