Fix for satellite hosts that are unable to contact their relayhost

because the DNS lookup is either impossible (.local domain), or
incorrect (certain openstack/amazon/piston cloud configurations create
this setup when the relayhost is in the same cluster as the satellite).

Fixes #5225

Change-Id: Ifbc201678f2c0e97ee0e12bbf1c7f71d035d45c1

1 files changed, 24 insertions, 0 deletions

diff --git a/puppet/modules/site_postfix/manifests/satellite.pp b/puppet/modules/site_postfix/manifests/satellite.pp
index 7be51b22..f5d5c7b7 100644
--- a/puppet/modules/site_postfix/manifests/satellite.pp
+++ b/puppet/modules/site_postfix/manifests/satellite.pp
@@ -10,5 +10,29 @@ class site_postfix::satellite {
     root_mail_recipient => $root_mail_recipient
   }
 
+  # There are special conditions for satellite hosts that will make them not be
+  # able to contact their relayhost:
+  #
+  # 1. they are on openstack/amazon/PC and are on the same cluster as the relay
+  # host, the MX lookup for the relay host will use the public IP, which cannot
+  # be contacted
+  #
+  # 2. When a domain is used that is not in DNS, because it is internal,
+  # a testing domain, etc. eg. a .local domain cannot be looked up in DNS
+  #
+  # to resolve this, so the satellite can contact the relayhost, we need to set
+  # the http://www.postfix.org/postconf.5.html#smtp_host_lookup to be 'native'
+  # which will cause the lookup to use the native naming service
+  # (nsswitch.conf), which typically defaults to 'files, dns' allowing the
+  # /etc/hosts to be consulted first, then DNS if the entry doesn't exist.
+  #
+  # NOTE: this will make it not possible to enable DANE support through DNSSEC
+  # with http://www.postfix.org/postconf.5.html#smtp_dns_support_level - but
+  # this parameter is not available until 2.11. If this ends up being important
+  # we could also make this an optional parameter for providers without
+  # dns / local domains
+
+  postfix::config { 'smtp_host_lookup': value => 'native'; }
+
   include site_postfix::mx::smtp_tls
 }