cmd/cli: ignore un-usable interfaces on darwin when resetDNS

cmd/cli/os_darwin.go

@@ -56,6 +56,18 @@ func setDNS(iface *net.Interface, nameservers []string) error {
 	return nil
 }
 
+// resetDnsIgnoreUnusableInterface likes resetDNS, but return a nil error if the interface is not usable.
+func resetDnsIgnoreUnusableInterface(iface *net.Interface) error {
+	if err := resetDNS(iface); err != nil {
+		// TODO: investiate whether we can detect this without relying on error message.
+		if strings.Contains(err.Error(), " is not a recognized network service") {
+			return nil
+		}
+		return err
+	}
+	return nil
+}
+
 // TODO(cuonglm): use system API
 func resetDNS(iface *net.Interface) error {
 	if ns := savedStaticNameservers(iface); len(ns) > 0 {

cmd/cli/os_freebsd.go

@@ -54,6 +54,11 @@ func setDNS(iface *net.Interface, nameservers []string) error {
 	return nil
 }
 
+// resetDnsIgnoreUnusableInterface likes resetDNS, but return a nil error if the interface is not usable.
+func resetDnsIgnoreUnusableInterface(iface *net.Interface) error {
+	return resetDNS(iface)
+}
+
 func resetDNS(iface *net.Interface) error {
 	r, err := dns.NewOSConfigurator(logf, iface.Name)
 	if err != nil {

cmd/cli/os_linux.go

@@ -119,6 +119,11 @@ func setDNS(iface *net.Interface, nameservers []string) error {
 	return nil
 }
 
+// resetDnsIgnoreUnusableInterface likes resetDNS, but return a nil error if the interface is not usable.
+func resetDnsIgnoreUnusableInterface(iface *net.Interface) error {
+	return resetDNS(iface)
+}
+
 func resetDNS(iface *net.Interface) (err error) {
 	defer func() {
 		if err == nil {

cmd/cli/os_windows.go

@@ -67,6 +67,11 @@ func setDNS(iface *net.Interface, nameservers []string) error {
 	return nil
 }
 
+// resetDnsIgnoreUnusableInterface likes resetDNS, but return a nil error if the interface is not usable.
+func resetDnsIgnoreUnusableInterface(iface *net.Interface) error {
+	return resetDNS(iface)
+}
+
 // TODO(cuonglm): should we use system API?
 func resetDNS(iface *net.Interface) error {
 	resetDNSOnce.Do(func() {

cmd/cli/prog.go

@@ -520,7 +520,7 @@ func (p *prog) resetDNS() {
 	}
 	logger.Debug().Msg("Restoring DNS successfully")
 	if allIfaces {
-		withEachPhysicalInterfaces(netIface.Name, "reset DNS", resetDNS)
+		withEachPhysicalInterfaces(netIface.Name, "reset DNS", resetDnsIgnoreUnusableInterface)
 	}
 }