From cb31ac08740f764a9b69ece7c8841b727d162ca7 Mon Sep 17 00:00:00 2001
From: Zicheng Huang <lorqor@gmail.com>
Date: Wed, 24 Aug 2022 12:53:13 +0200
Subject: [PATCH] Resolve comments

---
 cmd/node-cache/app/cache_app_test.go |  2 +-
 cmd/node-cache/app/configmap.go      | 10 +++++-----
 pkg/dns/config/config.go             |  7 +++----
 3 files changed, 9 insertions(+), 10 deletions(-)

diff --git a/cmd/node-cache/app/cache_app_test.go b/cmd/node-cache/app/cache_app_test.go
index 7caed0202..922f64e0c 100644
--- a/cmd/node-cache/app/cache_app_test.go
+++ b/cmd/node-cache/app/cache_app_test.go
@@ -246,7 +246,7 @@ func TestUpdateIPv6CoreFile(t *testing.T) {
 	}
 	customConfig := &config.Config{StubDomains: map[string][]string{
 		"acme.local":   {"2001:db8:1:1:1::1"},
-		"google.local": {"8.8.8.8"},
+		"google.local": {"2001:4860:4860::8888"},
 		"widget.local": {"[2001:db8:2:2:2::2]:10053", "2001:db8:3:3:3::3"},
 	},
 		UpstreamNameservers: []string{"[2001:db8:2:2:2::2]:10053", "2001:db8:3:3:3::3"},
diff --git a/cmd/node-cache/app/configmap.go b/cmd/node-cache/app/configmap.go
index 9efae5337..59fcadb3d 100644
--- a/cmd/node-cache/app/configmap.go
+++ b/cmd/node-cache/app/configmap.go
@@ -82,6 +82,11 @@ func getStubDomainStr(stubDomainMap map[string][]string, info *stubDomainInfo) s
 }
 
 func (c *CacheApp) updateCorefile(dnsConfig *config.Config) {
+	if err := dnsConfig.ValidateNodeLocalCacheConfig(); err != nil {
+		clog.Errorf("Invalid config: %v", err)
+		setupErrCount.WithLabelValues("configmap").Inc()
+		return
+	}
 	// construct part of the Corefile
 	baseConfig, err := ioutil.ReadFile(c.params.BaseCoreFile)
 	if err != nil {
@@ -89,11 +94,6 @@ func (c *CacheApp) updateCorefile(dnsConfig *config.Config) {
 		setupErrCount.WithLabelValues("configmap").Inc()
 		return
 	}
-	if err = dnsConfig.ValidateNodeLocalCacheConfig(); err != nil {
-		clog.Errorf("Invalid config: %v", err)
-		setupErrCount.WithLabelValues("configmap").Inc()
-		return
-	}
 
 	stubDomainStr := getStubDomainStr(dnsConfig.StubDomains, &stubDomainInfo{Port: c.params.LocalPort, CacheTTL: defaultTTL,
 		LocalIP: strings.Replace(c.params.LocalIPStr, ",", " ", -1)})
diff --git a/pkg/dns/config/config.go b/pkg/dns/config/config.go
index 274702456..c68cbf1b5 100644
--- a/pkg/dns/config/config.go
+++ b/pkg/dns/config/config.go
@@ -22,7 +22,6 @@ import (
 	"strconv"
 
 	"github.com/coredns/coredns/plugin/pkg/parse"
-
 	types "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/util/validation"
 	fed "k8s.io/dns/pkg/dns/federation"
@@ -136,9 +135,9 @@ func (config *Config) validateUpstreamNameserver() error {
 // ValidateNodeLocalCacheConfig returns nil if the config can be compiled
 // to a valid Corefile.
 func (config *Config) ValidateNodeLocalCacheConfig() error {
-	for _, stubDomains := range config.StubDomains {
-		if err := validateForwardProxy(stubDomains...); err != nil {
-			return err
+	for domain, nameservers := range config.StubDomains {
+		if err := validateForwardProxy(nameservers...); err != nil {
+			return fmt.Errorf("invalid nameservers %s for the stub domain %s: %v", nameservers, domain, err)
 		}
 	}
 	if err := validateForwardProxy(config.UpstreamNameservers...); err != nil {