Add JSON tags

go mod tidy

internal/dns/dns.go

@@ -172,6 +172,8 @@ func (m measurement) String() string {
 }
 
 func (s *Server) probeUpstreamLatency() {
+	if !s.once {
+		s.once = true
 		upstreams := s.upstreams()
 		results := make([]measurement, len(upstreams))
 		var wg sync.WaitGroup
@@ -199,13 +201,14 @@ func (s *Server) probeUpstreamLatency() {
 		sort.Slice(results, func(i, j int) bool {
 			return results[i].rtt < results[j].rtt
 		})
-	log.Printf("probe results: %v", results)
+		log.Printf("probe results: %v %v", s.once, results)
 		for idx, result := range results {
 			upstreams[idx] = result.upstream
 		}
 		s.upstreamMu.Lock()
 		defer s.upstreamMu.Unlock()
 		s.upstream = upstreams
+	}
 }
 
 func (s *Server) hostByName(n lcHostname) (string, bool) {
@@ -477,7 +480,6 @@ func (s *Server) handleInternal(w dns.ResponseWriter, r *dns.Msg) {
 		if err == errEmpty {
 			m := new(dns.Msg)
 			m.SetReply(r)
-			m.RecursionAvailable = true
 			w.WriteMsg(m)
 			return
 		}
@@ -486,7 +488,6 @@ func (s *Server) handleInternal(w dns.ResponseWriter, r *dns.Msg) {
 	if rr != nil {
 		m := new(dns.Msg)
 		m.SetReply(r)
-		m.RecursionAvailable = true
 		m.Answer = append(m.Answer, rr)
 		w.WriteMsg(m)
 		return
@@ -494,7 +495,6 @@ func (s *Server) handleInternal(w dns.ResponseWriter, r *dns.Msg) {
 	// Send an authoritative NXDOMAIN for local:
 	m := new(dns.Msg)
 	m.SetReply(r)
-	m.RecursionAvailable = true
 	m.SetRcode(r, dns.RcodeNameError)
 	w.WriteMsg(m)
 }
@@ -582,7 +582,6 @@ func (s *Server) subnameHandler(hostname lcHostname) func(w dns.ResponseWriter,
 			if err == errEmpty {
 				m := new(dns.Msg)
 				m.SetReply(r)
-				m.RecursionAvailable = true
 				w.WriteMsg(m)
 				return
 			}
@@ -592,7 +591,6 @@ func (s *Server) subnameHandler(hostname lcHostname) func(w dns.ResponseWriter,
 			s.promInc("local", r)
 			m := new(dns.Msg)
 			m.SetReply(r)
-			m.RecursionAvailable = true
 			m.Answer = append(m.Answer, rr)
 			w.WriteMsg(m)
 			return
@@ -603,7 +601,6 @@ func (s *Server) subnameHandler(hostname lcHostname) func(w dns.ResponseWriter,
 			s.promInc("local", r)
 			m := new(dns.Msg)
 			m.SetReply(r)
-			m.RecursionAvailable = true
 			m.SetRcode(r, dns.RcodeNameError)
 			w.WriteMsg(m)
 			return