From f10c6e2479afdd5a284fef4fc001784e31e5bce8 Mon Sep 17 00:00:00 2001
From: Kristoffer Dalby <kristoffer@tailscale.com>
Date: Fri, 16 Aug 2024 14:32:03 +0200
Subject: [PATCH] add warning on failing nameservers

Signed-off-by: Kristoffer Dalby <kristoffer@tailscale.com>
---
 hscontrol/types/config.go | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/hscontrol/types/config.go b/hscontrol/types/config.go
index 0beebea3db..e938768ea2 100644
--- a/hscontrol/types/config.go
+++ b/hscontrol/types/config.go
@@ -216,8 +216,6 @@ func LoadConfig(path string, isFile bool) error {
 		}
 	}
 
-	// viper.ExperimentalBindStruct()
-
 	envPrefix := "headscale"
 	viper.SetEnvPrefix(envPrefix)
 	viper.SetEnvKeyReplacer(strings.NewReplacer(".", "_"))
@@ -564,18 +562,27 @@ func (d *DNSConfig) GlobalResolvers() []*dnstype.Resolver {
 	var resolvers []*dnstype.Resolver
 
 	for _, nsStr := range d.Nameservers.Global {
+		warn := ""
 		if _, err := netip.ParseAddr(nsStr); err == nil {
 			resolvers = append(resolvers, &dnstype.Resolver{
 				Addr: nsStr,
 			})
 
 			continue
+		} else {
+			warn = fmt.Sprintf("Invalid global nameserver %q. Parsing error: %s ignoring", nsStr, err)
 		}
 
 		if _, err := url.Parse(nsStr); err == nil {
 			resolvers = append(resolvers, &dnstype.Resolver{
 				Addr: nsStr,
 			})
+		} else {
+			warn = fmt.Sprintf("Invalid global nameserver %q. Parsing error: %s ignoring", nsStr, err)
+		}
+
+		if warn != "" {
+			log.Warn().Msg(warn)
 		}
 	}
 
@@ -591,18 +598,27 @@ func (d *DNSConfig) SplitResolvers() map[string][]*dnstype.Resolver {
 	for domain, nameservers := range d.Nameservers.Split {
 		var resolvers []*dnstype.Resolver
 		for _, nsStr := range nameservers {
+			warn := ""
 			if _, err := netip.ParseAddr(nsStr); err == nil {
 				resolvers = append(resolvers, &dnstype.Resolver{
 					Addr: nsStr,
 				})
 
 				continue
+			} else {
+				warn = fmt.Sprintf("Invalid split dns nameserver %q. Parsing error: %s ignoring", nsStr, err)
 			}
 
 			if _, err := url.Parse(nsStr); err == nil {
 				resolvers = append(resolvers, &dnstype.Resolver{
 					Addr: nsStr,
 				})
+			} else {
+				warn = fmt.Sprintf("Invalid split dns nameserver %q. Parsing error: %s ignoring", nsStr, err)
+			}
+
+			if warn != "" {
+				log.Warn().Msg(warn)
 			}
 		}
 		routes[domain] = resolvers