fix: client/Dockerfile to reduce vulnerabilities (#3019)

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-ALPINE320-OPENSSL-8235201
- https://snyk.io/vuln/SNYK-ALPINE320-OPENSSL-8235201

Co-authored-by: snyk-bot <snyk-bot@snyk.io>

client/Dockerfile

@@ -1,4 +1,4 @@
-FROM alpine:3.20
+FROM alpine:3.21.0
 RUN apk add --no-cache ca-certificates iptables ip6tables
 ENV NB_FOREGROUND_MODE=true
 ENTRYPOINT [ "/usr/local/bin/netbird","up"]

client/internal/dns/server.go

@@ -374,8 +374,6 @@ func (s *DefaultServer) buildUpstreamHandlerUpdate(nameServerGroups []*nbdns.Nam
 			continue
 		}
 
-		log.Debugf("received a nameserver group with %#v nameservers for \"%s\" domains", nsGroup.NameServers, nsGroup.Domains)
-
 		handler, err := newUpstreamResolver(
 			s.ctx,
 			s.wgInterface.Name(),
@@ -446,11 +444,9 @@ func (s *DefaultServer) updateMux(muxUpdates []muxUpdate) {
 	var isContainRootUpdate bool
 
 	for _, update := range muxUpdates {
-		log.Debugf("registering a new handler for domain %s", update.domain)
 		s.service.RegisterMux(update.domain, update.handler)
 		muxUpdateMap[update.domain] = update.handler
 		if existingHandler, ok := s.dnsMuxMap[update.domain]; ok {
-			log.Debugf("stopping the existing handler for domain %s", update.domain)
 			existingHandler.stop()
 		}
 
@@ -466,7 +462,6 @@ func (s *DefaultServer) updateMux(muxUpdates []muxUpdate) {
 				s.addHostRootZone()
 				existingHandler.stop()
 			} else {
-				log.Debugf("stopping the existing handler for domain %s", key)
 				existingHandler.stop()
 				s.service.DeregisterMux(key)
 			}