From 11f03096d5b8ca4b1b4e407c679c47fd33242b62 Mon Sep 17 00:00:00 2001
From: Marc Fiuczynski <mef@cs.princeton.edu>
Date: Fri, 1 Feb 2008 21:03:12 +0000
Subject: [PATCH] Generalized logic for setting up /etc/resolv.conf and
/etc/hosts depending on whether myplc has DNS enabled or not.
If PLC's DNS (dnsmasq) is enabled, then:
1) /etc/resolv.conf will point at the local host and
/etc/plc_resolv.conf points either at:
a) the plc-config-tty configured DNS servers, or
b) the servers specific in the original /etc/resolv.conf
2) /etc/plc_hosts will contain a list of the currently configured
nodes. (This needs to be fixed, as the set of nodes and their
network settings can change).
If PLC's DNS (dnsmasq) is disabled, then /etc/resolv.conf will either :
a) remain untouched if PLC_NET_DNS{1,2} are not specified, or
b) be backed up to /etc/resolv_plc.backup and a new /etc/resolv.conf
will be generated with the PLC_NET_DNS{1,2} servers configured by
plc-config-tty
---
plc.d/dns | 67 ++++++++++++++++++++++++++++++++++++++++++++++---------
1 file changed, 56 insertions(+), 11 deletions(-)
diff --git a/plc.d/dns b/plc.d/dns
index b819e32..b195809 100755
--- a/plc.d/dns
+++ b/plc.d/dns
@@ -15,32 +15,77 @@
. /etc/plc.d/functions
. /etc/planetlab/plc_config
+SIGNATURE="; generated by /etc/plc.d/dns --- DO NOT REMOVE THIS TEXT!"
+
# Be verbose
set -x
case "$1" in
start)
- [ $PLC_DNS_ENABLED -ne 1 ] && exit 0
+ if [ $PLC_DNS_ENABLED -eq 1 ] ; then
+ MESSAGE=$"Starting DNS server"
+ dialog "$MESSAGE"
- MESSAGE=$"Starting DNS server"
- dialog "$MESSAGE"
+ dns-config
+ check
+ fi
- dns-config
- check
+ # Set up nameservers
+ if [ -n "$PLC_NET_DNS1" -o -n "$PLC_NET_DNS2" ] ; then
+ MESSAGE=$"Configuring resolv.conf"
+ dialog "$MESSAGE"
- plc_daemon dnsmasq
- check
+ rfile=$(mktemp)
+ (
+ echo $SIGNATURE
+ [ -n "$PLC_NET_DNS1" ] && echo "nameserver $PLC_NET_DNS1"
+ [ -n "$PLC_NET_DNS2" -a "$PLC_NET_DNS1" != "$PLC_NET_DNS2" ] && echo "nameserver $PLC_NET_DNS2"
+ ) > $rfile
+
+ if [ $PLC_DNS_ENABLED -eq 1 ] ; then
+ ourfile=$(grep "$SIGNATURE" /etc/resolv.conf| wc -l)
+ if [ $ourfile -eq 0 ] ; then
+ cp /etc/resolv.conf /etc/plc_resolv.conf
+ fi
+ else
+ cp /etc/resolv.conf /etc/resolv_plc.backup
+ fi
+ mv -f $rfile /etc/resolv.conf
+ chmod 444 /etc/resolv.conf
+ fi
+
+ if [ $PLC_DNS_ENABLED -eq 1 ] ; then
+ plc_daemon dnsmasq
+ check
+ fi
result "$MESSAGE"
;;
stop)
- [ $PLC_DNS_ENABLED -ne 1 ] && exit 0
- MESSAGE=$"Stopping DNS server"
+ MESSAGE=$"Reverting /etc/resolv.conf and /etc/hosts"
dialog "$MESSAGE"
+ if [ $PLC_DNS_ENABLED -eq 1 ] ; then
+ if [ -f "/etc/plc_resolv.conf" ] ; then
+ ourfile=$(grep "$SIGNATURE" /etc/plc_resolv.conf| wc -l)
+ if [ $ourfile -ne 0 ] ; then
+ dialog "WARNING: original /etc/resolv.conf was generated by etc/plc.d/dns"
+ fi
+ mv -f /etc/plc_resolv.conf /etc/resolv.conf
+ fi
+ [ -f "/etc/plc_hosts" ] && rm -f /etc/plc_hosts
+ fi
+ if [ $PLC_DNS_ENABLED -eq 0 -a -f "/etc/resolv_plc.backup" ] ; then
+ mv -f /etc/resolv_plc.backup /etc/resolv.conf
+ fi
+
+ if [ $PLC_DNS_ENABLED -eq 1 ] ; then
+ MESSAGE=$"Stopping DNS server"
+ dialog "$MESSAGE"
- killproc plc_dnsmasq
- check
+ killproc plc_dnsmasq
+ check
+ fi
result "$MESSAGE"
;;
--
2.47.0