refactor vault role (#2733)

* Move front-proxy-client certs back to kube mount

We want the same CA for all k8s certs

* Refactor vault to use a third party module

The module adds idempotency and reduces some of the repetitive
logic in the vault role

Requires ansible-modules-hashivault on ansible node and hvac
on the vault hosts themselves

Add upgrade test scenario
Remove bootstrap-os tags from tasks

* fix upgrade issues

* improve unseal logic

* specify ca and fix etcd check

* Fix initialization check

bump machine size

roles/kubernetes/master/templates/manifests/kube-apiserver.manifest.j2

@@ -117,8 +117,13 @@ spec:
     - --feature-gates={{ kube_feature_gates|join(',') }}
 {% endif %}
 {% if kube_version | version_compare('v1.9', '>=') %}
-    - --requestheader-client-ca-file={{ kube_cert_dir }}/front-proxy-ca.pem
+    - --requestheader-client-ca-file={{ kube_cert_dir }}/{{ kube_front_proxy_ca }}
+{# FIXME(mattymo): Vault certs do not work with front-proxy-client #}
+{% if cert_management == "vault" %}
+    - --requestheader-allowed-names=
+{% else %}
     - --requestheader-allowed-names=front-proxy-client
+{% endif %}
     - --requestheader-extra-headers-prefix=X-Remote-Extra-
     - --requestheader-group-headers=X-Remote-Group
     - --requestheader-username-headers=X-Remote-User