1#!/usr/bin/perl 2# 3# Copyright (C) Internet Systems Consortium, Inc. ("ISC") 4# 5# This Source Code Form is subject to the terms of the Mozilla Public 6# License, v. 2.0. If a copy of the MPL was not distributed with this 7# file, you can obtain one at https://mozilla.org/MPL/2.0/. 8# 9# See the COPYRIGHT file distributed with this work for additional 10# information regarding copyright ownership. 11 12# A simple nanny to make sure named stays running. 13 14$pid_file_location = '/var/run/named.pid'; 15$nameserver_location = 'localhost'; 16$dig_program = 'dig'; 17$named_program = 'named'; 18 19fork() && exit(); 20 21for (;;) { 22 $pid = 0; 23 open(FILE, $pid_file_location) || goto restart; 24 $pid = <FILE>; 25 close(FILE); 26 chomp($pid); 27 28 $res = kill 0, $pid; 29 30 goto restart if ($res == 0); 31 32 $dig_command = 33 "$dig_program +short . \@$nameserver_location > /dev/null"; 34 $return = system($dig_command); 35 goto restart if ($return == 9); 36 37 sleep 30; 38 next; 39 40 restart: 41 if ($pid != 0) { 42 kill 15, $pid; 43 sleep 30; 44 } 45 system ($named_program); 46 sleep 120; 47} 48