feat: prepare for dovecot deployment (#415)

- add dovecot role
- import dovecot module via r10k

Reviewed-on: #415

Puppetfile

@@ -63,6 +63,7 @@ mod 'rehan-mkdir', '2.0.0'
 mod 'tailoredautomation-patroni', '2.0.0'
 mod 'ssm-crypto_policies', '0.3.3'
 mod 'thias-sysctl', '1.0.8'
+mod 'cirrax-dovecot', '1.3.3'
 
 mod 'bind',
   :git => 'https://git.service.au-syd1.consul/unkinben/puppet-bind.git',

site/roles/manifests/infra/mail/backend.pp

@@ -0,0 +1,10 @@
+# a role to deploy a imap/pop3 backend for mail services
+class roles::infra::mail::backend {
+  if $facts['firstrun'] {
+    include profiles::defaults
+    include profiles::firstrun::init
+  }else{
+    include profiles::defaults
+    include profiles::base
+  }
+}