Add HA/LB endpoints for kube-apiserver

* Add auto-evaluated internal endpoints and clarify the loadbalancer_apiserver
vars and usecases.
* Add loadbalancer_apiserver_localhost (default false). If enabled, override
the external LB and expect localhost:443/8080 to be new internal only frontends.
* Add kube_apiserver_multiaccess to ignore loadbalancers, and make clients
to access the apiservers as a comma-separated list of access_ip/ip/ansible ip
(a default mode). When disabled, allow clients to use the given loadbalancers.
* Define connections security mode for kube controllers, schedulers, proxies.
It is insecure be default, which is the current deployment choice.
* Rework the groups['kube-master'][0] hardcode defining the apiserver
endpoints.
* Improve grouping of vars and add facts for kube_apiserver.
* Define kube_apiserver_insecure_bind_address as a fact, add more
facts for ease of use.

Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>

roles/kubernetes/node/templates/manifests/kube-proxy.manifest.j2

@@ -12,14 +12,10 @@ spec:
     - /hyperkube
     - proxy
     - --v={{ kube_log_level | default('2') }}
-{% if inventory_hostname in groups['kube-master'] %}
-    - --master=http://127.0.0.1:{{kube_apiserver_insecure_port}}
+{% if kube_proxy_insecure %}
+    - --master={{ kube_apiserver_insecure_endpoint }}
 {% else %}
-{%   if loadbalancer_apiserver is defined and apiserver_loadbalancer_domain_name is defined %}
-    - --master=https://{{ apiserver_loadbalancer_domain_name }}:{{ loadbalancer_apiserver.port }}
-{%   else %}
-    - --master=https://{{ hostvars[groups['kube-master'][0]]['access_ip'] | default(hostvars[groups['kube-master'][0]]['ip'] | default(hostvars[groups['kube-master'][0]]['ansible_default_ipv4']['address'])) }}:{{ kube_apiserver_port }}
-{%   endif%}
+    - --master={{ kube_apiserver_access_endpoint }}
     - --kubeconfig=/etc/kubernetes/node-kubeconfig.yaml
 {% endif %}
     - --bind-address={{ ip | default(ansible_default_ipv4.address) }}