From a35b6b1610699df2a59228cecb8ebc662181d34e Mon Sep 17 00:00:00 2001
From: Kees Monshouwer <mind04@monshouwer.org>
Date: Tue, 27 Dec 2016 14:39:51 +0100
Subject: [PATCH] Send a notification to all slave servers after every update.
 This will speed up the propagation of changes and is very useful for acme
 verification.

---
 docs/markdown/authoritative/dnsupdate.md      |  9 +++++++++
 docs/markdown/authoritative/domainmetadata.md |  2 +-
 pdns/rfc2136handler.cc                        | 11 +++++++++++
 3 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/docs/markdown/authoritative/dnsupdate.md b/docs/markdown/authoritative/dnsupdate.md
index 1d6be3f03e..08e1b9eaab 100644
--- a/docs/markdown/authoritative/dnsupdate.md
+++ b/docs/markdown/authoritative/dnsupdate.md
@@ -83,6 +83,15 @@ sql> insert into domainmetadata(domain_id, kind, content) values(5, ‘FORWARD-D
 
 There is no content, the existence of the entry enables the forwarding. This domain-specific setting is only useful when the configuration option **forward-dnsupdate** is set to 'no', as that will disable it globally. Using the domainmetadata setting than allows you to enable it per domain.
 
+## NOTIFY-DNSUPDATE
+Send a notification to all slave servers after every update. This will speed up the propagation of changes and is very useful for acme verification.
+
+```
+sql> select id from domains where name='example.org';
+5
+sql> insert into domainmetadata(domain_id, kind, content) values(5, ‘NOTIFY-DNSUPDATE’,’1’);
+```
+
 ## SOA-EDIT-DNSUPDATE
 This configures how the soa serial should be updated. See [below](#soa-serial-updates).
 
diff --git a/docs/markdown/authoritative/domainmetadata.md b/docs/markdown/authoritative/domainmetadata.md
index 70cc38e78c..84c9f4bbd3 100644
--- a/docs/markdown/authoritative/domainmetadata.md
+++ b/docs/markdown/authoritative/domainmetadata.md
@@ -33,7 +33,7 @@ To dissallow all IP's, except those explicitly allowed by domainmetadata records
 ## AXFR-SOURCE
 The IP address to use as a source address for sending AXFR and IXFR requests.
 
-## ALLOW-DNSUPDATE-FROM, TSIG-ALLOW-DNSUPDATE, FORWARD-DNSUPDATE, SOA-EDIT-DNSUPDATE
+## ALLOW-DNSUPDATE-FROM, TSIG-ALLOW-DNSUPDATE, FORWARD-DNSUPDATE, SOA-EDIT-DNSUPDATE, NOTIFY-DNSUPDATE
 See the documentation on [Dynamic DNS update](dnsupdate.md)
 
 ## ALSO-NOTIFY
diff --git a/pdns/rfc2136handler.cc b/pdns/rfc2136handler.cc
index 9e4df0b30c..7d872d5c17 100644
--- a/pdns/rfc2136handler.cc
+++ b/pdns/rfc2136handler.cc
@@ -14,9 +14,11 @@
 #include "resolver.hh"
 #include "dns_random.hh"
 #include "backends/gsql/ssql.hh"
+#include "communicator.hh"
 
 extern PacketCache PC;
 extern StatBag S;
+extern CommunicatorClass Communicator;
 
 pthread_mutex_t PacketHandler::s_rfc2136lock=PTHREAD_MUTEX_INITIALIZER;
 
@@ -947,6 +949,15 @@ int PacketHandler::processUpdate(DNSPacket *p) {
       zone.append("$");
       PC.purge(zone);
 
+      // Notify slaves
+      if (di.kind == DomainInfo::Master) {
+        vector<string> notify;
+        B.getDomainMetadata(p->qdomain, "NOTIFY-DNSUPDATE", notify);
+        if (!notify.empty() && notify.front() == "1") {
+          Communicator.notifyDomain(di.zone);
+        }
+      }
+
       L<<Logger::Info<<msgPrefix<<"Update completed, "<<changedRecords<<" changed records committed."<<endl;
     } else {
       //No change, no commit, we perform abort() because some backends might like this more.
-- 
2.47.2