Implement basic cloud provider functionality to deploy Kubernetes on
Azure. SaltStack is used to deploy Kubernetes on top of Ubuntu
virtual machines. OpenVpn provides network connectivity. For
kubelet authentication, we use basic authentication (username and
password). The scripts use the legacy Azure Service Management APIs.
We have set up a nightly test job in our Jenkins server for federated
testing to run the e2e test suite on Azure. With the cloud provider
scripts in this commit, 14 e2e test cases pass in this environment.
We plan to implement additional Azure functionality to support more
test cases.
We've had a lot of salt problems with systemd on AWS; we have a
workaround in place that we use everywhere else, we should use that for
kube-node-unpacker too.
Fixes#19386
Issue #19388
