Add k8s externaldns and coredns addons switchers

Those parameters needed to control deployment of externaldns and
coredns addons.
Also allowed to control externaldns image version and
base support of externaldns provider switch.
Externaldns and coredns disabled by default in any model.

Change-Id: I05fb713b7e7c053a990f4f3811a4c2042d420b36
diff --git a/classes/cluster/k8s-ha-contrail/kubernetes/control.yml b/classes/cluster/k8s-ha-contrail/kubernetes/control.yml
index 685ea2a..f086fd7 100644
--- a/classes/cluster/k8s-ha-contrail/kubernetes/control.yml
+++ b/classes/cluster/k8s-ha-contrail/kubernetes/control.yml
@@ -37,6 +37,12 @@
           namespace: ${_param:kubernetes_addon_namespace}
           enabled: ${_param:kubernetes_contrail_network_controller}
           image: ${_param:kubernetes_contrail_network_controller_image}
+        coredns:
+          enabled: ${_param:kubernetes_coredns_enabled}
+        externaldns:
+          enabled: ${_param:kubernetes_externaldns_enabled}
+          image: ${_param:kubernetes_externaldns_image}
+          provider: ${_param:kubernetes_externaldns_provider}
     master:
       etcd:
         ssl:
diff --git a/classes/cluster/k8s-ha-contrail/kubernetes/init.yml b/classes/cluster/k8s-ha-contrail/kubernetes/init.yml
index c999ca3..ad6ac37 100644
--- a/classes/cluster/k8s-ha-contrail/kubernetes/init.yml
+++ b/classes/cluster/k8s-ha-contrail/kubernetes/init.yml
@@ -30,6 +30,8 @@
     kubernetes_netchecker_server_image: mirantis/k8s-netchecker-server:v1.1.0
     kubernetes_netchecker_agent_probeurls: "http://ipinfo.io"
     kubernetes_virtlet_image: mirantis/virtlet:v0.7.0
+    kubernetes_externaldns_image: mirantis/external-dns:latest
+    kubernetes_externaldns_provider: coredns
 
     # switches of addons
     kubernetes_addon_namespace: kube-system
@@ -39,6 +41,8 @@
     kubernetes_calico_policy_enabled: false
     kubernetes_virtlet_enabled: false
     kubernetes_contrail_network_controller: true
+    kubernetes_coredns_enabled: false
+    kubernetes_externaldns_enabled: false
 
     # addresses and hostnames
     kubernetes_internal_api_address: 10.254.0.1