internal/router/dnsmasq: disable cache

So multiple upstreams config could work properly.

internal/router/edgeos/edgeos.go

@@ -15,11 +15,12 @@ import (
 )
 
 const (
-	Name                       = "edgeos"
-	edgeOSDNSMasqConfigPath    = "/etc/dnsmasq.d/dnsmasq-zzz-ctrld.conf"
-	usgDNSMasqConfigPath       = "/etc/dnsmasq.conf"
-	usgDNSMasqBackupConfigPath = "/etc/dnsmasq.conf.bak"
-	toggleContentFilteringLink = "https://community.ui.com/questions/UDM-Pro-disable-enable-DNS-filtering/e2cc4060-e56a-4139-b200-62d7f773ff8f"
+	Name                           = "edgeos"
+	edgeOSDNSMasqDefaultConfigPath = "/etc/dnsmasq.conf"
+	edgeOSDNSMasqConfigPath        = "/etc/dnsmasq.d/dnsmasq-zzz-ctrld.conf"
+	usgDNSMasqConfigPath           = "/etc/dnsmasq.conf"
+	usgDNSMasqBackupConfigPath     = "/etc/dnsmasq.conf.bak"
+	toggleContentFilteringLink     = "https://community.ui.com/questions/UDM-Pro-disable-enable-DNS-filtering/e2cc4060-e56a-4139-b200-62d7f773ff8f"
 )
 
 var ErrContentFilteringEnabled = fmt.Errorf(`the "Content Filtering" feature" is enabled, which is conflicted with ctrld.\n
@@ -95,7 +96,7 @@ func (e *EdgeOS) setupUSG() error {
 		return fmt.Errorf("setupUSG: backup current config: %w", err)
 	}
 
-	// Removing all configured upstreams.
+	// Removing all configured upstreams and cache config.
 	var sb strings.Builder
 	scanner := bufio.NewScanner(bytes.NewReader(buf))
 	for scanner.Scan() {
@@ -106,6 +107,9 @@ func (e *EdgeOS) setupUSG() error {
 		if strings.HasPrefix(line, "all-servers") {
 			continue
 		}
+		if strings.HasPrefix(line, "cache-size") {
+			continue
+		}
 		sb.WriteString(line)
 	}
 
@@ -127,6 +131,10 @@ func (e *EdgeOS) setupUSG() error {
 }
 
 func (e *EdgeOS) setupUDM() error {
+	// Disable dnsmasq cache.
+	if err := dnsmasq.DisableCache(edgeOSDNSMasqDefaultConfigPath); err != nil {
+		return err
+	}
 	data, err := dnsmasq.ConfTmpl(dnsmasq.ConfigContentTmpl, e.cfg)
 	if err != nil {
 		return err
@@ -153,6 +161,10 @@ func (e *EdgeOS) cleanupUSG() error {
 }
 
 func (e *EdgeOS) cleanupUDM() error {
+	// Enable dnsmasq cache.
+	if err := dnsmasq.EnableCache(edgeOSDNSMasqDefaultConfigPath); err != nil {
+		return err
+	}
 	// Remove the custom dnsmasq config
 	if err := os.Remove(edgeOSDNSMasqConfigPath); err != nil {
 		return fmt.Errorf("cleanupUDM: os.Remove: %w", err)