apply upstream fixes

lib/tapnet.pm

@@ -56,14 +56,12 @@ sub setup_tap_static {
 }
 
 sub get_host_dns {
-    # get DNS server addresses from the host
-    my @forwards;
-    open(FH, '<', "/etc/resolv.conf");
-    while (<FH>) {
-        if ($_ =~ m/^nameserver +(.+)/) {
-            push @forwards, $1;
-        }
-    }
+    # get DNS server addresses from the host. Assumes host uses
+    # systemd-resolved and doesn't use IPv6, for now
+    my $result = `/usr/bin/resolvectl status | grep Servers | tail -1 | cut -d: -f2-`;
+    # FIXME this is gonna break when we have IPv6 DNS servers on the
+    # worker hosts
+    my @forwards = split(' ', $result);
     return @forwards;
 }