From 9490b670984fb57fa5225a977be794883cf294a6 Mon Sep 17 00:00:00 2001
From: Remi Gacogne <remi.gacogne@powerdns.com>
Date: Tue, 11 Jun 2024 14:54:16 +0200
Subject: [PATCH] dnsdist: Get rid of the weird delayed tasks during
 configuration/startup

---
 pdns/dnsdistdist/dnsdist-lua.cc | 20 ++------------------
 pdns/dnsdistdist/dnsdist-lua.hh |  2 +-
 pdns/dnsdistdist/dnsdist.cc     | 13 ++++++++-----
 3 files changed, 11 insertions(+), 24 deletions(-)

diff --git a/pdns/dnsdistdist/dnsdist-lua.cc b/pdns/dnsdistdist/dnsdist-lua.cc
index 52a1b44d828c..c4e3ac95f6a7 100644
--- a/pdns/dnsdistdist/dnsdist-lua.cc
+++ b/pdns/dnsdistdist/dnsdist-lua.cc
@@ -82,8 +82,6 @@
 
 using std::thread;
 
-static std::optional<std::vector<std::function<void(void)>>> s_launchWork{std::nullopt};
-
 static boost::tribool s_noLuaSideEffect;
 
 /* this is a best effort way to prevent logging calls with no side-effects in the output of delta()
@@ -699,12 +697,7 @@ static void setupLuaConfig(LuaContext& luaCtx, bool client, bool configCheck)
                          }
 
                          if (ret->connected) {
-                           if (s_launchWork) {
-                             s_launchWork->push_back([ret]() {
-                               ret->start();
-                             });
-                           }
-                           else {
+                           if (!dnsdist::configuration::isConfigurationDone()) {
                              ret->start();
                            }
                          }
@@ -3365,12 +3358,8 @@ static void setupLuaConfig(LuaContext& luaCtx, bool client, bool configCheck)
   });
 }
 
-vector<std::function<void(void)>> setupLua(LuaContext& luaCtx, bool client, bool configCheck, const std::string& config)
+void setupLua(LuaContext& luaCtx, bool client, bool configCheck, const std::string& config)
 {
-  // this needs to exist only during the parsing of the configuration
-  // and cannot be captured by lambdas
-  s_launchWork = std::vector<std::function<void(void)>>();
-
   setupLuaActions(luaCtx);
   setupLuaConfig(luaCtx, client, configCheck);
   setupLuaBindings(luaCtx, client, configCheck);
@@ -3404,9 +3393,4 @@ vector<std::function<void(void)>> setupLua(LuaContext& luaCtx, bool client, bool
   }
 
   luaCtx.executeCode(ifs);
-
-  auto ret = std::move(*s_launchWork);
-  s_launchWork = std::nullopt;
-
-  return ret;
 }
diff --git a/pdns/dnsdistdist/dnsdist-lua.hh b/pdns/dnsdistdist/dnsdist-lua.hh
index 48d3ed2df59d..dd5ee053a9f3 100644
--- a/pdns/dnsdistdist/dnsdist-lua.hh
+++ b/pdns/dnsdistdist/dnsdist-lua.hh
@@ -170,7 +170,7 @@ std::shared_ptr<DNSRule> makeRule(const luadnsrule_t& var, const std::string& ca
 void parseRuleParams(boost::optional<luaruleparams_t>& params, boost::uuids::uuid& uuid, std::string& name, uint64_t& creationOrder);
 void checkParameterBound(const std::string& parameter, uint64_t value, size_t max = std::numeric_limits<uint16_t>::max());
 
-std::vector<std::function<void(void)>> setupLua(LuaContext& luaCtx, bool client, bool configCheck, const std::string& config);
+void setupLua(LuaContext& luaCtx, bool client, bool configCheck, const std::string& config);
 void setupLuaActions(LuaContext& luaCtx);
 void setupLuaBindings(LuaContext& luaCtx, bool client, bool configCheck);
 void setupLuaBindingsDNSCrypt(LuaContext& luaCtx, bool client);
diff --git a/pdns/dnsdistdist/dnsdist.cc b/pdns/dnsdistdist/dnsdist.cc
index 56b4472ad1fc..09bd364f88aa 100644
--- a/pdns/dnsdistdist/dnsdist.cc
+++ b/pdns/dnsdistdist/dnsdist.cc
@@ -3378,7 +3378,7 @@ int main(int argc, char** argv)
 
     dnsdist::g_asyncHolder = std::make_unique<dnsdist::AsynchronousHolder>();
 
-    auto todo = setupLua(*(g_lua.lock()), false, false, cmdLine.config);
+    setupLua(*(g_lua.lock()), false, false, cmdLine.config);
 
     setupPools();
 
@@ -3481,12 +3481,15 @@ int main(int argc, char** argv)
       webServerThread.detach();
     }
 
-    for (auto& todoItem : todo) {
-      todoItem();
-    }
-
     /* create the default pool no matter what */
     createPoolIfNotExists("");
+
+    for (auto& backend : dnsdist::configuration::getCurrentRuntimeConfiguration().d_backends) {
+      if (backend->connected) {
+        backend->start();
+      }
+    }
+
     if (!cmdLine.remotes.empty()) {
       for (const auto& address : cmdLine.remotes) {
         DownstreamState::Config config;