[client] Apply routes right away instead of on peer connection (#3907)

Author: lixmal

client/internal/dns/server.go

@@ -489,7 +489,7 @@ func (s *DefaultServer) applyHostConfig() {
 		}
 	}
 
-	log.Debugf("extra match domains: %v", s.extraDomains)
+	log.Debugf("extra match domains: %v", maps.Keys(s.extraDomains))
 
 	if err := s.hostManager.applyDNSConfig(config, s.stateManager); err != nil {
 		log.Errorf("failed to apply DNS host manager update: %v", err)

client/internal/engine.go

@@ -994,6 +994,15 @@ func (e *Engine) updateNetworkMap(networkMap *mgmProto.NetworkMap) error {
 		}
 	}
 
+	protoDNSConfig := networkMap.GetDNSConfig()
+	if protoDNSConfig == nil {
+		protoDNSConfig = &mgmProto.DNSConfig{}
+	}
+
+	if err := e.dnsServer.UpdateDNSServer(serial, toDNSConfig(protoDNSConfig, e.wgInterface.Address().Network)); err != nil {
+		log.Errorf("failed to update dns server, err: %v", err)
+	}
+
 	dnsRouteFeatureFlag := toDNSFeatureFlag(networkMap)
 
 	// apply routes first, route related actions might depend on routing being enabled
@@ -1061,15 +1070,6 @@ func (e *Engine) updateNetworkMap(networkMap *mgmProto.NetworkMap) error {
 	excludedLazyPeers := e.toExcludedLazyPeers(routes, forwardingRules, networkMap.GetRemotePeers())
 	e.connMgr.SetExcludeList(excludedLazyPeers)
 
-	protoDNSConfig := networkMap.GetDNSConfig()
-	if protoDNSConfig == nil {
-		protoDNSConfig = &mgmProto.DNSConfig{}
-	}
-
-	if err := e.dnsServer.UpdateDNSServer(serial, toDNSConfig(protoDNSConfig, e.wgInterface.Address().Network)); err != nil {
-		log.Errorf("failed to update dns server, err: %v", err)
-	}
-
 	e.networkSerial = serial
 
 	// Test received (upstream) servers for availability right away instead of upon usage.