From: Stephane Bakhos <sbakhos@datacandy.com>
Date: Thu, 23 Jul 2020 02:51:28 +0000 (-0400)
Subject: Add an option to toggle the reconnectOnUp option
X-Git-Tag: rec-4.4.0-beta1~50^2~1
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f7da1535de9d4d87b4502fc453f11264b4817c69;p=thirdparty%2Fpdns.git

Add an option to toggle the reconnectOnUp option
---

diff --git a/pdns/dnsdist-console.cc b/pdns/dnsdist-console.cc
index 9b3255db48..26b12012b9 100644
--- a/pdns/dnsdist-console.cc
+++ b/pdns/dnsdist-console.cc
@@ -462,7 +462,7 @@ const std::vector<ConsoleKeyword> g_consoleKeywords{
   { "newQPSLimiter", true, "rate, burst", "configure a QPS limiter with that rate and that burst capacity" },
   { "newRemoteLogger", true, "address:port [, timeout=2, maxQueuedEntries=100, reconnectWaitTime=1]", "create a Remote Logger object, to use with `RemoteLogAction()` and `RemoteLogResponseAction()`" },
   { "newRuleAction", true, "DNS rule, DNS action [, {uuid=\"UUID\"}]", "return a pair of DNS Rule and DNS Action, to be used with `setRules()`" },
-  { "newServer", true, "{address=\"ip:port\", qps=1000, order=1, weight=10, pool=\"abuse\", retries=5, tcpConnectTimeout=5, tcpSendTimeout=30, tcpRecvTimeout=30, checkName=\"a.root-servers.net.\", checkType=\"A\", maxCheckFailures=1, mustResolve=false, useClientSubnet=true, source=\"address|interface name|address@interface\", sockets=1}", "instantiate a server" },
+  { "newServer", true, "{address=\"ip:port\", qps=1000, order=1, weight=10, pool=\"abuse\", retries=5, tcpConnectTimeout=5, tcpSendTimeout=30, tcpRecvTimeout=30, checkName=\"a.root-servers.net.\", checkType=\"A\", maxCheckFailures=1, mustResolve=false, useClientSubnet=true, source=\"address|interface name|address@interface\", sockets=1, reconnectOnUp=false}", "instantiate a server" },
   { "newServerPolicy", true, "name, function", "create a policy object from a Lua function" },
   { "newSuffixMatchNode", true, "", "returns a new SuffixMatchNode" },
   { "NoneAction", true, "", "Does nothing. Subsequent rules are processed after this action" },
diff --git a/pdns/dnsdist-lua.cc b/pdns/dnsdist-lua.cc
index 39d2e595ad..796753ebc9 100644
--- a/pdns/dnsdist-lua.cc
+++ b/pdns/dnsdist-lua.cc
@@ -465,6 +465,10 @@ static void setupLuaConfig(bool client, bool configCheck)
         ret->minRiseSuccesses=std::stoi(boost::get<string>(vars["rise"]));
       }
 
+      if(vars.count("reconnectOnUp")) {
+        ret->reconnectOnUp=boost::get<bool>(vars["reconnectOnUp"]);
+      }
+
       if(vars.count("cpus")) {
         for (const auto& cpu : boost::get<vector<pair<int,string>>>(vars["cpus"])) {
           cpus.insert(std::stoi(cpu.second));
diff --git a/pdns/dnsdist.hh b/pdns/dnsdist.hh
index 1ffb3aeb74..0e413bcc84 100644
--- a/pdns/dnsdist.hh
+++ b/pdns/dnsdist.hh
@@ -843,6 +843,7 @@ struct DownstreamState
   std::atomic_flag threadStarted;
   bool tcpFastOpen{false};
   bool ipBindAddrNoPort{true};
+  bool reconnectOnUp{false};
 
   bool isUp() const
   {
diff --git a/pdns/dnsdistdist/dnsdist-healthchecks.cc b/pdns/dnsdistdist/dnsdist-healthchecks.cc
index 5b9716c504..ce79c3405b 100644
--- a/pdns/dnsdistdist/dnsdist-healthchecks.cc
+++ b/pdns/dnsdistdist/dnsdist-healthchecks.cc
@@ -60,7 +60,7 @@ void updateHealthCheckResult(const std::shared_ptr<DownstreamState>& dss, bool n
   if(newState != dss->upStatus) {
     warnlog("Marking downstream %s as '%s'", dss->getNameWithAddr(), newState ? "up" : "down");
 
-    if (newState) {
+    if (newState && dss->reconnectOnUp) {
       newState = dss->reconnect();
 
       if (dss->connected && !dss->threadStarted.test_and_set()) {
diff --git a/pdns/dnsdistdist/docs/reference/config.rst b/pdns/dnsdistdist/docs/reference/config.rst
index 2a036de868..6297ce487e 100644
--- a/pdns/dnsdistdist/docs/reference/config.rst
+++ b/pdns/dnsdistdist/docs/reference/config.rst
@@ -469,7 +469,8 @@ Servers
       sockets=NUM,           -- Number of sockets (and thus source ports) used toward the backend server, defaults to a single one
       disableZeroScope=BOOL, -- Disable the EDNS Client Subnet 'zero scope' feature, which does a cache lookup for an answer valid for all subnets (ECS scope of 0) before adding ECS information to the query and doing the regular lookup. This requires the ``parseECS`` option of the corresponding cache to be set to true
       rise=NUM,              -- Require NUM consecutive successful checks before declaring the backend up, default: 1
-      useProxyProtocol=BOOL  -- Add a proxy protocol header to the query, passing along the client's IP address and port along with the original destination address and port. Default is disabled.
+      useProxyProtocol=BOOL, -- Add a proxy protocol header to the query, passing along the client's IP address and port along with the original destination address and port. Default is disabled.
+      reconnectOnUp=BOOL     -- Close and reopen the sockets when a server transits from Down to Up. This helps when an interface is missing when dnsdist is started. Default is disabled.
     })
 
   :param str server_string: A simple IP:PORT string.