cmd/ctrld: add --iface for setting DNS on specific interface

nameservers_unix.go

@@ -3,21 +3,9 @@
 package ctrld
 
 import (
-	"net"
-
-	"tailscale.com/net/dns/resolvconffile"
+	"github.com/Control-D-Inc/ctrld/internal/resolvconffile"
 )
 
-const resolvconfPath = "/etc/resolv.conf"
-
 func nameservers() []string {
-	c, err := resolvconffile.ParseFile(resolvconfPath)
-	if err != nil {
-		return nil
-	}
-	ns := make([]string, 0, len(c.Nameservers))
-	for _, nameserver := range c.Nameservers {
-		ns = append(ns, net.JoinHostPort(nameserver.String(), "53"))
-	}
-	return ns
+	return resolvconffile.NameServersWithPort()
 }