Small code enhancements

integration/fake_dns_server.go

@@ -93,7 +93,9 @@ func (s *handler) ServeDNS(w dns.ResponseWriter, r *dns.Msg) {
 	auth.Minttl = 1
 	m.Ns = append(m.Ns, auth)
 
-	w.WriteMsg(m)
+	if err := w.WriteMsg(m); err != nil {
+		log.Fatalf("Failed to write message %v", err)
+	}
 }
 
 func startFakeDNSServer() *dns.Server {