desginate: simplify sample pool and modify it for HA (SOC-9142)

In crowbar's world the dns-master is the master of all and slaves
forward all queries to dns-master. When designate is enabled,
designate-mdns service component(s) become the hidden master(s).

We leave 'also_notifies' empty. It can be configured by the users
via designate-manage utility as and when needed.

designate-mdns service components, in HA, will be
running on multiple hosts and any host can be asked to update a zone
(when a recordset, corresponding to a vm is created) on th real-master so
all have to be listed as master in the pool.

The host with VIP will use that ip as the outgoing ip when connecting
to the real-master, so it should also be named as master for the zone.

chef/cookbooks/designate/recipes/mdns.rb

@@ -20,15 +20,23 @@
 
 dns = node_search_with_cache("roles:dns-server").first
 dnsmaster = dns[:dns][:master_ip]
-dnsslaves = dns[:dns][:slave_ips].to_a
-dnsservers = [dnsmaster] + dnsslaves
 
-network_settings = DesignateHelper.network_settings(node)
+# hidden masters are designate-mdns services, in ha this service will be running on multiple
+# hosts and any host can be asked to update the zone (when a recordset, corresponding to a vm is
+# created) on the real-master so all have to be listed as master in the pool.
+hiddenmasters = node_search_with_cache("roles:designate-server").map do |n|
+  { "host" => Barclamp::Inventory.get_network_by_type(n, "admin").address, "port" => 5354 }
+end
+
+# the host with VIP will use that ip as the outgoing ip when connecting to the real-master
+if node[:designate][:ha][:enabled]
+  hiddenmasters += [{ "host" => CrowbarPacemakerHelper.cluster_vip(node, "admin"), "port" => 5354 }]
+end
 
 # One could have multiple pools in designate. And
 # designate needs to have a default pool, this pools
 # id is hardcoded in the designate conf. By reusing that
-# id we let designate know how crowbar's deployement of
+# id we let designate know how crowbar's deployment of
 # dns servers looks like.
 # This pool id can be generated by in proposal, but this will change
 # with every delete/create cycle of proposal. This might mess
@@ -41,11 +49,11 @@
   "attributes" => {},
   "ns_records" => [{ "hostname" => "#{dns[:fqdn]}.", "priority" => 1 }],
   "nameservers" => dnsservers.map { |ip| { "host" => ip, "port" => 53 } },
-  "also_notifies" => dnsslaves.map { |ip| { "host" => ip, "port" => 53 } },
+  "also_notifies" => [],
   "targets" => [{
     "type" => "bind9",
-    "description" => "BIND9 Server 1",
-    "masters" => [{ "host" => network_settings[:mdns_bind_host], "port" => 5354 }],
+    "description" => "BIND9 Server on node with role dns-server",
+    "masters" => hiddenmasters,
     "options" => {
       "host" => dnsmaster,
       "port" => 53,