feat: manage externaldns bind (#428)

- add module to manage externaldns bind for k8s
- add infra::dns::externaldns role
- add 198.18.19.20 as anycast for k8s external-dns service

Reviewed-on: #428

modules/externaldns/manifests/init.pp

@@ -0,0 +1,15 @@
+# ExternalDNS BIND module - automatically configures master or slave
+class externaldns (
+  Stdlib::Fqdn $bind_master_hostname,
+  Array[Stdlib::Fqdn] $k8s_zones = [],
+  Array[Stdlib::Fqdn] $slave_servers = [],
+  String $externaldns_key_secret = '',
+  String $externaldns_key_algorithm = 'hmac-sha256',
+) {
+
+  if $trusted['certname'] == $bind_master_hostname {
+    include externaldns::master
+  } else {
+    include externaldns::slave
+  }
+}