Haproxy endpoint resource: set defaults for server_names and IPs

It's not trivial to set the server names and IP addresses for dynamic
haproxy endpoints due to the fact that hiera renders the array as a
string. In order to make this work, we try to be clever and get the
server names and IPs from hiera directly as a default value. This should
work as long as the endpoint uses the same name as the service.

Closes-Bug: #1743626
Change-Id: I51eebfeceb5915fb0add8332c50386f6df93dca5

manifests/haproxy/endpoint.pp

@@ -24,16 +24,18 @@
 # [*service_port*]
 #  The default port on which the endpoint will be listening.
 #
-# [*ip_addresses*]
-#  The ordered list of IPs to be used to contact the balancer member.
-#
-# [*server_names*]
-#  The names of the balancer members, which usually should be the hostname.
-#
 # [*member_options*]
 #  Options for the balancer member, specified after the server declaration.
 #  These should go in the member's configuration block.
 #
+# [*ip_addresses*]
+#  The ordered list of IPs to be used to contact the balancer member.
+#  Defaults to hiera("${name}_node_ips", undef)
+#
+# [*server_names*]
+#  The names of the balancer members, which usually should be the hostname.
+#  Defaults to hiera("${name}_node_names", undef)
+#
 # [*public_virtual_ip*]
 #  Address in which the proxy endpoint will be listening in the public network.
 #  If this service is internal only this should be ommitted.
@@ -99,9 +101,9 @@
 define tripleo::haproxy::endpoint (
   $internal_ip,
   $service_port,
-  $ip_addresses,
-  $server_names,
   $member_options,
+  $ip_addresses                = hiera("${name}_node_ips", undef),
+  $server_names                = hiera("${name}_node_names", undef),
   $public_virtual_ip           = undef,
   $mode                        = undef,
   $haproxy_listen_bind_param   = undef,